Home/class 11

StackOverflow Latest Questions

W3spoint99
  • 0
W3spoint99Begginer
Asked: January 17, 2025In:
  • 0

Please Explain Measurement of Area, Volume and Density (Class 11 – Physics).

class 11densitymeasurement of areasciencevolume
  1. Saralyn
    Saralyn Begginer

    When Humans look at their childhood pictures, the first thing they realize is how tall or heavy they have become as compared to the early stages of their lives. Noticing the increment in the weight or becoming taller is done through measurement. Measurement is required everywhere in order to specifiRead more

    When Humans look at their childhood pictures, the first thing they realize is how tall or heavy they have become as compared to the early stages of their lives. Noticing the increment in the weight or becoming taller is done through measurement. Measurement is required everywhere in order to specifically compare a quantity’s value from its original value. There can be many examples where measurement is required, For example, a thermometer is used to measure the temperature in Celsius of the body, the clocks on the wall are used to measure time in hours, and so on.

    Measurement

    Calculating the value of one quantity by comparing it with the standard value of the same physical quantity is called Measurement. It can be said that measurement associates the physical quantity with its numeric value.

    Normally, objects are measured by placing them next to each other, and it can be explained which one is heavier or taller, etc. Measuring an object gives two results- value and unit of the quantity. For example, The length of the scale is 15 cm long where 15 is the value and the centimeter is the unit used for length.

    Metric System

    Metric system is the system that came from the decimal system and this system is used to measure basic quantities, metric system paves the way for the conversion of units, that is, the conversion of bigger units into smaller and vice-versa is possible due to the system. The basic quantities that are present are meter, gram, and liters, and they are used to measuring quantities of length, volume/mass, and capacity.

    Measurement of Length

    According to the metric system, length is calculated in meters. However, it can easily be converted into other forms depending upon the requirement, for instance, if the requirement is to measure the bigger quantity, it should be measured in kilometers, if the requirement is to measure something smaller, it should be in centimeters. Let’s say, the requirement is to measure a certain distance, it should either be in meters or kilometers.

    Below is the easier way to explain the conversion,

    Measurement of Area

    In the standard way, the area of any quantity is measured in meter2, since the area is a two-dimensional quantity that is scalar in nature. It involves lengths going in two different directions known as length and breadth. The area of bigger and smaller quantities can be converted easily using different units, for example, if the area of a small table is to be measured, it is measured in cm2 and if the area of the plot is to be measured, the unit used is meter2.

    Below is the easier way to explain the conversion,

    Measurement of Volume

    The volume of any quantity is three-dimensional in nature, that is, the length if going in three directions, unlike length or area, the volume contains capacity. The standard unit used to measure volume is meter3. The unit is converted into bigger and smaller units like decimeter3 or kilometer3 based on how big or small the quantity is, it is done by simply dividing/ multiplying by tens, hundreds, thousands, and so on.

    Below is the easier way to explain the conversion,

    Measurement of Density

    The density of any object is defined as the mass of that object per unit volume. Density tells how close or far away molecules are packed in a certain volume. The very famous scientist known as Archimedes discovered the concept of the Density of an object. In the metric system, Density is measured in kg/m3 and is represented as D or ρ. Therefore, it can be denoted as,

    Density (D\ or\ ρ)=\frac {Mass}{Volume}(kg/m^3)

    Note:

    • Density has big significance in real life. One example to prove the same is the concept of an object floating on water, The density of any object helps in identifying whether an object can float on water or not. If the density of the object is lesser than that of water (997.7 kg/m3), it will float on water.
    • The SI unit of density is kg/m3, but for measurement of solids, g/cm3 can also be used. In order to measure the density of liquids, mostly g/ml is used.

    Sample Problems

    Question 1: Convert the following: m3 to mm3, liter to meter3, mile3 to km3.

    Solution:

    The conversion of the above-mentioned quantities are as follows,

    • m3 to mm3

    1 meter = 1000 millimeters

    1m3= 1000 × 1000 × 1000 mm3

    Therefore, 1m3 = 1 × 109 m3.

    • Liter to meter3

    It is known that 1 meter3 = 1000 liters

    By unitary method, 1 liters = 1/1000 m3

    1 liter= 1 × 10-3 m3.

    • Mile3 to km3

    1 mile = 1.609 km

    1 mile3 = 1.609 × 1.609 × 1.609 km3

    1 mile3 = 4.165 km3

    Question 2: What is the difference between the metric system and the imperial system of measurement?

    Answer:

    Difference between metric system and imperial system,

    Metric system Imperial system
    Known as International systems of units Known as British imperial system
    Measurement is done in Meter, gram and liter Measurement is done in feet, pound, inches
    Simple conversion (used by 95% of population currently) Complex conversion

    Question 3: Calculate the density of an object having a mass of 1200kg and its volume is 10m3.

    Solution:

    Density of an object is given as,

    Density (D\ or\ ρ)=\frac {Mass}{Volume}(kg/m^3)

    D = 1200/10 kg/m3

    D = 120 kg/m3.

    Question 4: There are two large boxes filled with biscuits. The first has 10 biscuits and the second has 20 biscuit packets present in it. The box have the same volume. Explain which box will weigh more?

    Answer:

    The concept is based on density. Density of an object is defined as mass/volume. Here, both the boxes have equal volume but the mass of the second box is more as it contain twice as many biscuits as first box. Hence, the second box will weigh more.

    Question 5: A cube is given which has a volume of 1000m3. Calculate the surface area of the cube in cm3.

    Solution:

    The surface area of a cube = 6a2

    where a is the length if the side of cube

    Given, Volume of cube= 1000m3 =a3

    a = 10meter

    Surface area (in meter2) = 6 × 102 = 600meter2

    1 meter= 100 centimeter

    1 m2= 100 × 100 cm2

    Therefore, Surface area of the cube= 600 × 104 cm2.

    Question 6: The length and the breadth of a cuboid are same, but the height is twice in value. If the volume of the cuboid is 54000m3, find the length, breadth and height of the cuboid in centimeters.

    Solution:

    Volume of a cuboid = L × B × H= 54000m3

    Let the length and breadth be z, then the height will be 2z

    2z × z× z= 54000

    2z3= 54000

    z3= 27000

    z= 30m

    Length= 30m, Breadth= 30m, Height = 60m

    In centimeters, Length= 30× 100= 3000cm

    Breadth = 30 × 100= 3000cm

    Height= 60 × 1000= 6000cm

    Question 7: A cm scale has a limit of 15 points, how long is the scale in meters?

    Solution:

    Converting cm scale into m scale,

    1 cm = 10-2m

    15 cm = 0.15m

    Hence, a 15cm long scale has a length of 0.15m in International System of Units.

    See less
W3spoint99
  • 0
W3spoint99Begginer
Asked: January 17, 2025In:
  • 0

Please Explain Length Measurement (Class 11 – Physics).

class 11length measurementphysicsscience
  1. Saralyn
    Saralyn Begginer

    Previously, length was measured using units such as the length of a foot, the breadth of a palm, and so on. The ‘Cubit’ was one of the first means of measuring length. It is the length of the arm from the elbow to the tip of the fingers. These units vary from person to person, resulting in non-unifoRead more

    Previously, length was measured using units such as the length of a foot, the breadth of a palm, and so on. The ‘Cubit’ was one of the first means of measuring length. It is the length of the arm from the elbow to the tip of the fingers. These units vary from person to person, resulting in non-uniform measures.

    How can we know how far the moon is from the earth or how far the moon is from the sun? How did we determine the earth’s diameter? Measuring length isn’t always simple or easy. We’ll try to respond to these queries in the sections below. In addition, we will learn about the many methods for measuring length.

    Length

    The measurement or amount of anything from one end to other is referred to as length.

    In other terms, it is the largest of the two or the highest of three geometrical form or item dimensions. The width and length of a rectangle, for instance, are its dimensions. Furthermore, under the International System of Quantities, length is a quantity with the dimension distance.

    The meter, abbreviated as m, is the basic unit for length in the International System of Units (SI). The length or distance is measured in kilometers (km), meters (m), decimeters (dm), centimeters (cm), and millimeters (mm) in the metric system (mm). It is possible to convert quantities from meters to centimeters, kilometers to meters, centimeters to millimeters, and so on.

    Measurement of Length

    There were no modes of transportation available in ancient times. People used to travel on foot or by using animals to transport goods. Over time, the term “wheel” was coined. This signified a significant shift in human forms of transportation. Since then, new forms of transportation have been invented and improved regularly. The steam engine was created, and it had a great influence and was instrumental in shaping the world as we know it today.

    As a result, transportation has a lengthy history. Did the folks have any idea how far they had to go? To go to any location, one must first determine how far away it is. This aids in deciding whether to walk, take the train, bus, or fly to that location. To determine how far apart two locations are, we must first determine the distance between them. But what exactly does measurement imply? What is the best way to measure a physical quantity? The comparing of an unknown amount to a known amount is known as measurement. A numerical number known as “magnitude” and a “unit” are used to indicate the outcome of the measurement. A ‘unit’ is a pre-determined unit of comparison against which other physical quantities are measured.

    The length of the foot, the breadth of the palm, and other such quantities were used to measure the length in the past. The ‘Cubit’ was one of the first means of measuring length. It is the length of an arm measured from elbow to tips of fingers. These units varied from person to person, resulting in non-uniform measures. A set of standard units of measurement has been recognised all around the world to preserve uniformity in measurements.

    The International System of Units (SI) is one of the most widely used measurement systems in the world. The basic unit of length in the SI system is the meter. The C.G.S. system is another system of units in which the centimeter is the basic unit of length.

    Conventional Methods of Measurements

    Historically, the human body served as the foundation for length units.

    • Inch: An inch is a unit of measurement that was once used to measure the length of little things such as the length of paper, the seam of cloth, and so on.
    • Foot: A foot is a unit of length that is commonly defined as 15.3 per cent of a human body’s height, with an average height of 160 cm. This unit differed from one location to the next and from one transaction to the next. The Romans and Greeks favored this unit, which was commonly used to compute the height of humans and livestock, the size of a piece of fabric, the size of a structure, and so on.
    • Cubit: A cubit is a unit of length based on the length of the forearm, which is commonly measured from the tip of the middle finger to the forearm’s length bottom of the elbow. The Egyptians and Mesopotamians favored this unit. Cubit rods have been unearthed among the ancient Egyptian civilization’s relics. These rods are typically 20 inches long and are split into seven palms, each of which is split into four fingers, which are further subdivided.
    • Yard: A yard is a measurement of distance based on human paces. It is usually measured in two cubits, which is around 36 inches.
    • Mile: A mile is equal to 1,000 paces, where a pace is equal to two steps and the walker returns to the same foot.

    A foot is 12 inches long, and a yard is three feet long. It was simple to describe how distant the next village was and to determine if an object would fit through a doorway using these dimensions. These dimensions also made it easier for individuals to swap garments and wood.

    Scale

    Triangulation Method

    Let’s take a closer look at what the triangulation approach entails. How might triangulation assist us in determining the distances between distant stars? The parallax approach makes use of the fact that a triangle may be entirely defined using only three parts. Triangulation is the process of determining the values of a triangle to determine an item’s position. Surveyors and architects frequently employ such techniques.

    Triangulation is the method of identifying the location of a point by calculating the angles to it from two known sites rather than calculating distances directly.

    Triangulation Example

    Let’s put this into practice with a real-life scenario. How can we estimate a large object distance from any distance without actually measuring it? It may be measured using the triangulation method.

    Triangulation Method of measurement

    • Let’s start by constructing a fixed baseline with two points AB.
    • The angle formed by point A concerning the object is denoted by α, whereas the angle formed by point B concerning the object is marked by β.
    • Now that we have the baseline AB and the angles, we can determine the remainder of the triangle’s attributes, such as the position of the third point, which is the object.

    Parallax Method

    The displacement or shift in the apparent location of an item when observed from two distinct points of view is known as parallax.

    The two places of vision each have their own line of sight, and parallax is defined as half the angle between them. When you’re driving in a car and glance about, you’ll notice that items far away appear to move more slowly than items closer to you. This is the parallax effect. Because the parallax of nearby objects is greater than that of distant ones, the parallax may be utilised to measure distances.

    When the phenomena of parallax is coupled with triangulation, the position of the item may be determined with great precision. The parallax method is commonly used by astronomers to determine the distances between stars.

    Distance Measurement by Parallax Method

    The principle of triangulation is used to the measuring of distance through parallax. We learned from triangulation that a triangle may be completely specified if two angles and sides are known.

    The distance of a faraway star is being computed in the image below. The star closer to Earth than the farthest one gives the limited parallax value. By observing the star from two known places on Earth that form the triangle’s baseline, we may determine the value of the parallax angle.

    Parallax Method

    Let’s denote the parallax half-angle between two places on Earth ‘p.’ The radius of the Earth is the greatest value of ‘d,’ and the distance of the star may be considered to be just slightly more than that of the sun. Because the distance from the sun is several orders of magnitude lower than the radius of the Earth, the parallax angle we obtain is exceedingly modest.

    Application

    The distance to an object measured in parsecs (in terms of light speed) is equal to the reciprocal of parallax angle measured in arcseconds.

    Relation between the distance of a star, and its parallax is given as:

    D = 1 ⁄ p

    where D is the distance of star and p is the parallax angle.

    To solve the difficulty of tiny ratios, the parallax of a star is most commonly estimated using yearly parallax, which is defined as the difference in a star’s location as seen from the Earth and the Sun. Instead of using the Earth’s radius as a fixed baseline, the radius of the Earth’s revolution around the Sun is used, which increases the size of the baseline and hence the top angle, making it simpler to measure.

    However, for any celestial objects near to the Earth, we can consider the diameter of the Earth as a baseline, and the distance of any celestial objects is given as:

    x = b ⁄ θ

    where x is the distance of the object from the Earth, b is the baseline or diameter of the Earth and θ is the angle subtended by the object.

    Sample Problems

    Problem 1: If a person covers 1.5 yards in one step, how much distance will he cover in 30 steps?

    Solution:

    Given:

    Total number of steps, n = 30

    Value of 1 step, d = 1.5 yards

    Total distance covered by the person, D = n d

    = 30 × 1.5 yard

    = 45 yards

    Hence, the distance covered by the person is 45 yards.

    Problem 2: Astronomers apply which method to determine how far away a star is?

    Answer:

    Astronomers use parallax to calculate the distance between stars. Trigonometric parallax is another name for parallax.

    Problem 3: What is parallax?

    Answer:

    The two items appear to be coincident when seen in a straight line. There is a relative displacement between the things if they are at separate locations and the eye is shifted sideways. The closer item travels in the opposite direction from the eye, whereas the further object travels in the same direction.

    When two things are perceived in a straight line and the eye is shifted to the side, this is referred to as parallax.

    Problem 4: What was the conventional method of measuring the length?

    Answer:

    The length was measured in history with the help of human body. These were based on the several methods like distance from tip of middle finger to bottom of elbow, or human paces or human heights, etc. However, it was discarded later because these methods were different for different countries and were limited to measure the long distances.

    Problem 5: The Moon subtends an angle of 1° 55’ at the baseline equal to the diameter of the Earth. What is the distance of the Moon from the Earth? (Radius of the Earth is 6.4 × 106 m)

    Solution:

    Given:

    The angle subtended by moon, θ = 1° 55’ = 115’

    We know, 1’ = 60’’ and 1’’ = 4.85 × 10-6 rad

    Therefore, 115’ = (115 × 60)’’ × 4.85 × 10-6 rad = 3.34 × 10-2 rad

    The baseline for the Moon is the diameter of the Earth, b = 2 × 6.4 × 106 m = 1.28 × 107 m

    Distance of the Moon from the Earth, x = b ⁄ θ

    = 1.28 × 107 m ⁄ 3.34 × 10-2 rad

    = 3.83 × 108 m

    Hence, the distance of the Moon from the Earth is 3.83 × 108 m.

    See less
W3spoint99
  • 0
W3spoint99Begginer
Asked: January 17, 2025In:
  • 0

Please Explain System of Units (Class 11 – Physics).

class 11physicssciencesystem of units
  1. Saralyn
    Saralyn Begginer

    Measurement forms the fundamental principle to various other branches of science, that is, construction and engineering services. Measurement is defined as the action of associating numerical with their possible physical quantities and phenomena. Measurements find a role in everyday activities to aRead more

    Measurement forms the fundamental principle to various other branches of science, that is, construction and engineering services. Measurement is defined as the action of associating numerical with their possible physical quantities and phenomena. Measurements find a role in everyday activities to a large extent. Therefore, it is necessary to study and explore the associated elements along with their theoretical foundations, conditions as well as limitations. It defines the units to be chosen for the measurement of various commodities. It also caters to the comparison of plausible units with the ones already existing of a similar kind.

    Measurement defined the new standards as well as form transductions for the quantities which do not have any possible access for direct comparison. These physical quantities can be converted into analogous measurement signals.

    Measurements may be made by unaided human senses, generally termed as estimates. It can also be estimated by the use of instruments, which may range in complexity from simple rules for measuring lengths to highly complex analogous systems to handle and design the commodities beyond the capabilities of the senses. Thus, the measurements may range from buying some quantity of milk (in L) or to the highly complex mechanisms, such as radio waves from a distant star or the nuclear bomb radiations. Therefore, we can consider that a measurement, always involves a transfer of energy or interaction between the object and the observer or observing instrument.

    Measurement of Height of a person

    Unit

    The unit of a specified physical quantity can be considered as an arbitrarily chosen standard that can be used to estimate the quantities belonging to similar measurements. The units are well accepted and recognized by the people and well within all guidelines.

    A physical quantity is measured in terms of the chosen standards of measurement.

    The chosen standard is recognized as the unit of that corresponding physical quantity. A standard unit, in short, is a definite amount of a physical quantity. These standard units can be quickly reproduced to create a wide variety of units and are internationally accepted and accessible.

    The measurement of any physical quantity is based on a formula, nu,

    where, n = numerical value of the measure of the quantity,

    u = unit of the quantity.

    Standard

    The actual physical embodiment of the unit of a physical quantity is termed as a standard of that physical quantity. The standard is expressed in terms of the numerical value (n) and the unit (μ).

    Measurement of physical quantity = Numerical value × Unit

    For example: Length of a rod = 12 m. Here 12 is its numerical segment and m (meter) is the unit.

    Fundamental Units

    Fundamental units are elementary in nature, that is, they can be expressed independently without any dependence on any other physical quantity. This implies that it is not possible to resolve it further in terms of any other physical quantity. It is also termed as a basic physical quantity. Fundamental quantities have their own values and units.

    Fundamental Quantities Fundamental Units Symbol
    Length meter m
    Mass kilogram kg
    Time second s
    Temperature kelvin k
    Electric current ampere A
    Luminous intensity candela cd
    Amount of substance mole mol

    Supplementary Fundamental Units

    There are two other supplementary fundamental units, namely Radian and steradian are two supplementary which measures plane angle and solid angle respectively.

    Supplementary Fundamental Quantities Supplementary Unit
    Plane angle radian
    Solid angle steradian
    • Radian (rad)
      One radian is equivalent to an angle subtended at the center of a circle by an arc of length equal to the radius of the circle. It is the unit represented for the plane angle.

    θ = 1 radian

    dθ=\left(\frac{ds}{r}\right)\ radian

    • Steradian (sr)
      One steradian is equivalent to the solid angle subtended at the center of a sphere by its surface. Its area is equivalent to the square of the radius of the sphere.It is the unit represented for the solid angle. Solid angle in steradian,

    Ω = 1 steradian

    dΩ =\frac{Area\ cut\ out\ from\ the\ surface\ of\ sphere}{(Radius)^2}\\ dΩ =\left(\frac{dA}{r^2}\right)\ steradian

    Properties of Fundamental Units

    Any standard unit should have the following two properties:

    • Invariability
      The standard unit must be invariable. Thus, defining distance between the tip of the middle finger and the elbow as a unit of length is not invariable.
    • Availability
      The standard unit should be easily made available for comparing with other quantities.

    The seven fundamental units of S.I. have been defined as under.

    • Meter (m)
      Defined as 1650763.73 times the wavelength, in vacuum of the orange light emitted in transition from 2p10­  to 5d5.
    • Kilogram (kg) 
      Defined as the mass of a platinum-iridium cylinder kept at Serves.
    • Second (s) 
      Time taken by 9192631770 cycles of the radiation from the hyperfine transition in cesium – 133 when unperturbed by external fields.
    • Ampere (A)
      The constant current which, if maintained in each of two infinitely long, straight, parallel wires of negligible cross-section placed 1 m apart, in vacuum, produces between the wires a force of 2×10-7 newton per meter length of the wires.
    • Kelvin (K)
      Temperature is measured with absolute zero as the zero and the triple point of water as the upper fixed point on the thermodynamic scale. The interval is divided into 273.15 divisions and each division is considered to be unit temperature.
    • Candela (cd)
      The luminous intensity in the perpendicular direction of a surface of \frac{1}{600000} square meter of a full radiator at the temperature of freezing platinum under a pressure of 101325 newtons per square meter.
    • Mole (mol)
      The mole is the amount of any substance which contains as many elementary entities as there are atoms in 0.012 kg of the carbon isotope \frac{12}{6} C.

    Derived units

    The derived units are in usage for the commodities where the units are obtained from a combination of fundamental units. Derived units are sometimes assigned names. For instance, the S.I unit of force is kg ms-2 , termed as Newton (N). The unit of power is kg m2 s-3 , termed as watt (W).

    Steps to find Derived Units

    • Fetch the formula for the quantity whose unit is to be derived.
    • Substitute units of all the involved quantities. The chosen units should all belong to one system on units in their fundamental or standard form.
    • Simplify for the derived unit of the quantity to compute its final unit.

    Example: Compute the unit of velocity.

    Since, we know velocity is a derived quantity, obtained from distance and time(fundamental quantities).

    Mathematically ,

    velocity =  displacement/time

    S.I. unit of velocity = \frac{S.I.\ unit\ of\ displacement}{ S.I.\ unit\ of\ time}  = m/s

    Thus S.I. unit of velocity is m/s.

    Some Important derived units

    Some of the derived units have been given specific names, depending on the increase in their usage , though they are not recognized in S.I units.

    • Micron (mm) = 10-6 m
    • Angstrom (Å)  = 10-10 m
    • Fermi (fm) = 10-15 m
    • Barn (b) = 10-28 m2

    Systems of Units

    Any system of units contains the entire set of both fundamental as well as derived units, for all kinds of physical quantities. The preferred system of units are the following :

    • CGS System  (Centimeter Gram Second)
      The unit of length is centimeter, the unit of mass is gram and the unit of time is second according to the guidelines of this system.
    • FPS System  (Foot Pound Second)
      The unit of length is foot, the unit of mass is pound and the unit of time is second according to the guidelines of this system.
    • MKS System (Meter Kilogram Second)
      The unit of length is meter, the unit of mass is kilogram and the unit of time is second according to the guidelines of this system.
    • SI System 
      The System Internationale d’ Units, that is S.I system contains seven fundamental units and two supplementary fundamental units.

    Note:

    While computation of values for any physical quantity, the units for the involved derived quantities are treated as algebraic quantities till the desired units are obtained.

    Advantages of S.I Unit System

    The S.I unit of measurement is preferred over other units of measurement, because,

    • It is internationally accepted.
    • It is a metric system.
    • It is a rational and coherent unit system,
    • Easy conversion between CGS and MKS systems of units.
    • Uses decimal system, which is easy to understand and apply.

    Other Important Units of Length

    The distances can be infinitely larger in magnitude, which cannot be depicted in terms of meters or kilometers. For instance, the distances of planets and stars etc. Therefore, it is necessary to use some larger units of length such as ‘astronomical unit’, ‘light year’, parsec’ etc. while making such calculations, some of which are :

    • Astronomical Unit – The average separation between the Earth and the sun.
      1 AU = 1.496 x 1011 m.
    • Light Year – The distance travelled by light in vacuum in one year.
      1 light year = 9.46 x 1015 m.
    • Parsec – The distance at which an arc of length of one astronomical unit subtends an angle of one second at a point.
      1 parsec = 3.08 x 1016 m
    • Fermi – Size of a nucleus is expressed in ‘fermi’.
      1 fermi = If = 10-15 m
    • Angstrom – Size of a tiny atom
      1 angstrom = 1A = 10-10 m

    Sample Problems

    Problem 1. Convert the unit of G, which is gravitational constant, G = 6.67 x 10-11Nm2/kg2 in CGS system.

    Solution: 

    Since, we have

    G = 6.67 x 10-11 Nm2/kg2

    Converting kg into grams, 1 kg = 1000 gms

    = 6.67 x 10-11 x 108 x 103 cm3/g1 s2

    = 6.67 x 108  cm3/g1 s2

    Problem 2. Name the S.I units of the following commodities : 

    a. Pressure

    b. Solid angle

    c. Luminous intensity.

    Solution: 

    a. Pascal

    b. Steradian

    c. Candela

    Problem 3. Derive the S.I unit of latent heat. 

    Solution: 

    Latent heat = \frac{Heat energy}{Mass}

    Latent\space Heat = \frac{Q}{m} \\ =\frac{ kg m^2 s^{-2}}{kg} \\ = m^2 s^{-2}

    Problem 4: How are A0 and A.U related? 

    Solution: 

    Describing both quantities in terms of meters,

    Ao = 10-10m

    and 1 A.U. = 1.4961011m.

    Therefore,

    1 A.U. =  1.496 x 1011 x 1010 A0

    1 A.U = 1.496 x 1021 A0

    Problem 5: Describe 1 light-year in meters. 

    Solution: 

    A light-year is a distance travelled by light in 1 year with the speed of light :

    = 9.46 x 1011 m

    See less
W3spoint99
  • 0
W3spoint99Begginer
Asked: December 30, 2024In:
  • 0

Explain Diversity In The Living World (Class 11 – Biology) – Notes.

biologyclass 11living world
  1. Saralyn
    Saralyn Begginer
    This answer was edited.

    Diversity In The Living World Each residing life form will in general share highlights like development, upkeep of homeostasis, propagation, utilization of energy, adaption, and so forth. These highlights help to recognize various species and furthermore prove to be useful in laying out a connectionRead more

    Diversity In The Living World

    Each residing life form will in general share highlights like development, upkeep of homeostasis, propagation, utilization of energy, adaption, and so forth. These highlights help to recognize various species and furthermore prove to be useful in laying out a connection between organic entities with a typical hereditary part.

    Biodiversity: Biodiversity is every one of the various types of life you’ll track down in one region — the range of creatures, plants, growths, and even microorganisms like microbes that make up our normal world. Every one of these animal categories and living beings cooperates in environments, similar to a multifaceted web, to keep up with equilibrium and back life. Biodiversity upholds everything in nature that we want to get by food, clean water, medication, and asylum.

    • Taxonomy: Taxonomy is the area of science that manages the recognizable proof, terminology, and grouping of creatures.
    • Identification: Identification is the acknowledgment of the fundamental person of a life form.
    • Nomenclature: Nomenclature is the naming of life forms. Latinized names are utilized to allude to various types of plants and creatures.

    Features of Living World 

    • Development: The expansion in cells’ number and mass through cell division.
    • Material sense: It is the capacity to detect the climate.
    • Digestion: A progression of biochemical responses happening in the body to shape and change substance organization.
    • Proliferation: The method involved creating posterity and proceeding with the progeny.
    • Organization: The very characterizing qualities of every living organic entity.
    • Cognizance: The feeling of monitoring one’s environmental factors, activities, and aims.

    Diversity in the Living World

    Diversity in Living Organism

    The world is overwhelmed by plenty of living organic entities living in the land, water, ice, sweets, and so forth. Each living organic entity is one of a kind of structure, body capabilities, hereditary make-up, etc. The living life forms found in various natural surroundings have different primary organs or capabilities created according to the states of their environment. Organic entities have advanced to adjust to their evolving surroundings. Various sorts and classes of life forms possessing various conditions are known as biodiversity. Districts that are warm and damp have more different organic entities and are called super biodiversity.

    People have advanced from primates. However, presently they don’t appear to be comparative in any capacity. Likewise, every individual is not quite the same as the other. Each individual has an alternate skin tone, hair tone, and eyes, and generally significant of everything is hereditary cosmetics. And that implies that the qualities of each and every individual are unique.

    In this manner, to recognize better, we have made gatherings of creatures that in some way seem to be comparative and have a few utilitarian and primary similitudes. This is known as order. There are different variables that impact the order of creatures. It is significantly done based on the accompanying models

    • Presence of core
    • Body plan which infers the make-up of cells or the presence of single or numerous cells
    • Food creation
    • Level of the association in groups of creatures completing photosynthesis
    • In creatures – an association of one’s body parts, advancement of body, particular organs for various capabilities, organs frameworks.

    Classification System

    The grouping of life forms is finished by two techniques. One is characterizing them into plants and creatures and the other one which is a five-realm framework is a more nitty-gritty and coordinated characterization of living beings:

    • Two-Kingdom Classification- It was proposed via Carolus Linnaeus. He ordered organic entities into two classifications, plants, and creatures.
    • Five-Kingdom Classification- It was proposed by Whittaker. He separated the life forms into five distinct classes.
      • Monera
      • Protista
      • Fungi
      • Plantae
      • Animalia

    Hierarchy of Classification

    Carolus Linnaeus additionally organized the organic entities into various scientific classifications at various levels. These scientific classifications in a chronic request are as per the following

    • Kingdom
    • Phylum
    • Class
    • Order
    • Family
    • Genus
    • Species

    Characteristics of Five Kingdoms

    Kingdom Monera

    These are unicellular prokaryotes. The life forms come up short on the evident nucleus. They might contain a cell wall. They might be heterotrophic or autotrophic in nature. For instance Bacteria, Cyanobacteria.

    Kingdom Protista

    Protista are unicellular and eukaryotic organic entities go under this group. They display an autotrophic or heterotrophic method of nutrition. They show the presence of pseudopodia, cilia, or flagella for headway. For instance one-celled critter, paramecium.

    Kingdom Fungi

    These are multicellular, eukaryotic organisms. They have a saprophytic method of nourishment which includes chemoheterotrophic extracellular processing. The cell wall in these organic entities is comprised of chitin. They live in a cooperative relationship with blue-green growth. For instance Yeast, Aspergillus

    Kingdom Plantae

    These are multicellular, eukaryotic organisms. The cell mass of these creatures is comprised of cellulose. They are heterotrophs and set up their own food through photosynthesis. Kingdom Plantae is partitioned into Thallophyta, Bryophyta, Pteridophyta, Gymnosperms, and Angiosperms. For instance Pines, plants, palm trees, mango trees, and so on.

    Kingdom Animalia

    Kingdom Animalia is multicellular, eukaryotic living beings yet they don’t show the presence of cell walls. They are heterotrophs or creatures who can’t set up their own food. Both straightforward and complex life forms are found in this gathering and it’s an extremely general gathering of organisms. The organic entities are hereditarily diverse. They display an organ-framework level of organization. It is partitioned into various phyla like Porifera, Coelenterata, Echinodermata, Chordata, Annelids, and so on. For instance Earthworms, Hydra, and so on.

    FAQs on Diversity In The Living World

    Question 1: Why are living creatures arranged?

    Answer:

    A colossal assortment of plants, creatures, and organisms are tracked down on the planet. This multitude of living creatures varies in size, shape, variety, natural surroundings, and numerous different attributes. As there is an enormous number of living organic entities on the planet, concentrating on every one of them is unimaginable. Accordingly, researchers have concocted systems to arrange every single living creature. These strategies for arrangement depend on decisions and rules that permit recognizable proof, terminology, and lastly characterization of an organic entity.

    Question 2: Why are the order frameworks changing occasionally?

    Answer:

    Huge quantities of plants, creatures, and microorganisms are tracked down on the planet. A significant number of these have been recognized by researchers while numerous new species are as yet being found all over the planet. In this manner, to order these newfound species, new frameworks of the arrangement must be determined from time to time. This makes the necessity to change the current frameworks of order.

    Question 3: What various measures could you decide to group individuals that you meet frequently?

    Answer:

    The different standards that might be decided to arrange individuals whom we meet frequently incorporate a way of behaving, geological area, morphology, relatives, family members, companions, and so forth.

    Question 4: What do we gain from distinguishing proof of people and the populace?

    Answer:

    The information on attributes of an individual or its entire populace helps in recognizable proof of similitudes and dissimilarities among the people of a comparative kind or between various sorts of life forms. It assists us with grouping living beings into different classes relying on these similitudes and dissimilarities.

    Question 5: Given underneath is the logical name of Mango. Recognize the accurately composed name. Mangifera Indica

    Answer:

    In the binomial arrangement of terminology, the conventional name of an animal group generally begins with a capital letter though the particular name begins with a little letter. Accordingly, the right logical name for Mango is Mangifera indica.

    See less
W3spoint99
  • 0
W3spoint99Begginer
Asked: December 30, 2024In:
  • 0

Explain Fundamental Forces in Nature (Class 11 – Physics) – Notes

cbseclass 11forcesfundamentalnaturephysics
  1. Saralyn
    Saralyn Begginer

    Fundamental Forces The most beautiful phenomenon that can be seen in physics is that how universe is so disciplined and synced together. The force has kept the universe bind together. Forces have always played an important role in the human existence, but it is not realized by humans. Human beings cRead more

    Fundamental Forces

    The most beautiful phenomenon that can be seen in physics is that how universe is so disciplined and synced together. The force has kept the universe bind together. Forces have always played an important role in the human existence, but it is not realized by humans. Human beings constantly experience some force acting on them like gravitational force, etc.  There are some forces that naturally exist in the universe, they are known as Fundamental Forces. Let’s learn about them in some detail.

    Force

    Force is an interaction, either with contact or without contact. When there is no opposition given to the Force, It can result in changing the motion, shape, position, of a body. Whenever some interaction occurs between two objects, there is a certain force acting upon them. There are many types of Forces present, For instance, Applied Force, Gravitational Force, Frictional Force, Tension Force, etc.

    Fundamental Forces in nature

    These forces are so well-defined that they cover the macroscopic and microscopic forces present in nature. The forces learned or seen by humans in everyday life, from frictional force, pull, push, thrust, etc. are known as derived forces, and they are not considered the fundamental forces. The derived forces are actually derived from the fundamental forces in some way or the other. Some Fundamental Forces are,

    • Gravitational Force
    • Electromagnetic Force
    • Strong Nuclear Force
    • Weak Nuclear Force

    These above-mentioned forces are responsible for all the observations obtained in forces present in the nature.

    Gravitational Force

    This force exists by the virtue of the masses of any objects. Gravitational force is the mutual force of attraction between two masses. Attraction between any mass and Earth is called Gravity. Isaac Newton first gave the concept of gravity. Gravity is the most intuitive and the weakest force present in nature. The Irony is that Gravity actually holds the planet, Solar system, Entire Universe together, yet it is known to be the weakest force present in nature.

    The Force of Gravitation is given as,

    Formula for Gravitational Force,

    F1=F2=G\frac{M1.M2}{r^2}

    Where, F = Force of Gravitation

    M1, M2 = Masses 1 and 2

    r = Distance between the masses

    G = Gravitational Constant (6.67× 10-11m3kg-1s-2)

    Electromagnetic Force

    Charges when they are at rest exert a force at each other known as the Electric force of attraction/repulsion. Like charges repel each other while unlike charges attract each other. When charges start to move and become dynamic, they develop magnetic field lines around and have magnetic force, these two forces combined are known as Electromagnetic forces present in nature.

    Magnetic force produced by current (moving charge)

    Combining the above two forces which are always perpendicular to each other will give rise to Electromagnetic Force. The force is produced by massless bosons and photons present in the charges, Electromagnetic force exists in nature and is responsible for many derived forces we experience every day, for example, Friction Force, Normal Force, Elasticity, and so on.

    Strong Nuclear Force

    It is the force of attraction between Protons and Neutrons. The force is the same whether protons and protons are present or neutrons and neutrons are present or protons and neutrons are looked at. In short, a Strong nuclear force exists between all nucleons. In short Ranges, this Force is the strongest among all the forces. It is important to note that at a distance of 10-13 cm, this force vanishes.

    Weak Nuclear Force 

    This Force is seen In the β Decay of a nucleus. Scientist named Wolfgang Pauli First predicted a particle named Neutrino. The Neutrino is an uncharged Particle that is released along with the electron in the β Decay process. During β Decay, when Beta Particle is ejected from an Atom, it tends to accelerate away from the atom and some force is required to accelerate the particle known as Weak Nuclear Force. Weak Nuclear Force is stronger than gravitational force but weaker than a strong nuclear force. 

    Table to represent Range and Relative Strength of Different Forces:

    Forces Range Relative strength
    Gravitational Force ∞ 10-38
    Electromagnetic Force ∞ 10-2
    Strong nuclear force < 10-15m 1
    Weak nuclear Force < 10-18m 10-13

    Conceptual Questions

    Question 1: Which Fundamental Force is the strongest and weakest among the fundamental forces present in nature?

    Answer:

    The strongest force present in nature is the Strong Nuclear Force and the weakest force present in nature at atomic scale is Gravity.

    Question 2: Which of the following forces are Fundamental, and which are derived in nature?

    Weak Nuclear Force, Friction Force, Gravity, Elasticity, Electromagnetic Force, Push

    Answer:

    Fundamental Forces ⇢ Weak Nuclear Force, Gravity, Electromagnetic Force.

    Derived Force ⇢ Friction Force, Elasticity, Push.

    Question 3: A statement is being used now “Gravity is not a force” Throw light on this statement.

    Answer:

    Isaac Newton initially discovered Gravity and Gravitational Force. It was then stated that gravity is a Force. Later on, with the help of Theory of Relativity, Einstein stated that Gravity is actually not a force but a result of space-time orientation. It is a consequence of masses moving along a geodesic lines in space time.

    Question 4: If the masses of 2 objects are doubled and the space between them is also doubled. How will the gravitational Force between them change?

    Answer:

    Gravitational Force is given as,

    F_G=G\frac{M_1.M_2}{r^2}

    When, Mass 1 and Mass 2 is doubled, M1’=2M1, M2’=2M2

    Distance between the masses is doubled, r’= 2r

    New Gravitational Force Between them,

    F_G'=G\frac{M_1'.M_2'}{r'^2}=G\frac{2M_1.2M_2}{4r^2} \\=G\frac{M_1.M_2}{r^2}=F_G

    Hence, The new value of gravitational Force will be same as the old Gravitational Force.

    Question 5: What are Pseudo Forces? Give Examples.

    Answer:

    Pseudo Forces are also known as Inertial Force or Fictitious Force. These forces actually do not exist and are the apparent forces that are seen due to fact that they are defined from a non-inertial frame.

    Example: A man sees another man going in a car and realized that some force is acting on the man in the car. This type of force seen is real as it is seen from a non-accelerated or inertial frame. However, the man in the car if looks at the man standing would feel that some force is acted upon the man and he is going backwards, this force is pseudo force, Since this force is seen from a non-inertial frame or an accelerated frame.

    Question 6: Which two forces have infinite range?

    Answer:

    The two fundamental forces having infinite range are Gravitational force and Electromagnetic force.

    See less
W3spoint99
  • 0
W3spoint99Begginer
Asked: December 27, 2024In:
  • 0

Explain – Representation of a Set (Class 11 – Maths). Please also Provide Some examples.

class 11examplemathssetsolution
  1. Saralyn
    Saralyn Begginer

    Imagine a very haphazard world where no categories are divided to memorize and classify things separately, a world like this will be full of chaos and mess, this is why humans prefer to categorize things and classify them to neatly understand and remember them. The same case happens in mathematics,Read more

    Imagine a very haphazard world where no categories are divided to memorize and classify things separately, a world like this will be full of chaos and mess, this is why humans prefer to categorize things and classify them to neatly understand and remember them. The same case happens in mathematics, studying math involves dealing with a lot of data, and when the data can be grouped, it is preferred to group them and categorize them, hence, Sets come into play.

     

    What are the Sets in Mathematics?

    Sets are defined as the collection of well-defined data. In Math, a Set is a tool that helps to classify and collect data belonging to the same category, even though the elements used in sets are all different from each other, they all are similar as they belong to one group. For instance, a set of different outdoor games, say set A= {Football, basketball, volleyball, cricket, badminton} all the games mentioned are different, but they all are similar in one way as they belong to the same group (outdoor games).

    The set is denoted as a capital letter, for example, set A, set B, etc., and the elements belonging to the set are denoted as a small letter, and they are kept in curly brackets {}, for example, set A= {a, b, c, d}, as it is clear that a, b, c, d belong to set A, it can be written a ∈ A, do p belong to set A? No. Therefore, it will be written as, p∉ A.

    Representation of Sets

    Sets can be represented in two ways, one is known as the Roster form and the other is famous as the Set-Builder form, these two forms can be used to represent the same data, but the style varies in both cases.

    Roster Form

    In Roster Form, the elements are inside {}⇢ Curly brackets. All the elements are mentioned inside and are separated by commas. Roster form is the easiest way to represent the data in groups. For example, the set for the table of 5 will be, A= {5, 10, 15, 20, 25, 30, 35…..}.

    Properties of Roster Formrelations of Sets:

    • The arrangement in the Roster form does not necessarily to be in the same order every time. For example, A= {a, b, c, d, e} is equal to A= {e, d, a, c, b}.
    • The elements are not repeated in the set in Roster form, for example, the word “apple” will be written as, A= {a, p, l, e}
    • The Finite sets are represented either with all the elements or if the elements are too much, they are represented as dots in the middle. The infinite sets are represented with dots in the end.

    Set-Builder Form

    In Set-builder form, elements are shown or represented in statements expressing relations among elements. The standard form for Set-builder, A= {a: statement}. For example, A = {x: x = a3, a ∈ N, a < 9}

    Properties of Set-builder form:

    • In order to write the set in Set- builder form, the data should follow a certain pattern.
    • Colons (:) are necessary in Set-builder form.
    • After colon, the statement is to be written.

    Order of the Set

    The order of the Set is determined by the number of elements present in the Set. For example, if there are 10 elements in the set, the order of the set becomes 10. For finite sets, the order of the set is finite, and for infinite sets, the order of the set is infinite.

    Sample Problems

    Question 1: Determine which of the following are considered assetsin and which are not.

    1. All even numbers on the number line.
    2. All the good basketball players from class 9th.
    3. The bad performers from the batch of dancers.
    4. All prime numbers from 1 to 100.
    5. Numbers that are greater than 5 and less than 15.

    Answer: 

    Sets are not those bunches or groups where some quality or characteristic comes in the picture. Therefore,

    1. “All even numbers on the number line” is a set.
    2. “All the good basketball players from class 9th” is not a Set as “good” is a quality which is involved.
    3. “The bad performers from the batch of dancers” cannot be a Set since “bad” is a characteristic.
    4. “All prime numbers from 1 to 100” is a Set.
    5. “Numbers that are greater than 5 and less than 15” is a Set.

    Question 2: Represent the following information inSet-Builder the Roster form.

    1. All Natural numbers.
    2. Numbers greater than 6 and less than 3.
    3. All even numbers from 10 to 25.

    Answer:

    The Roster form for the above information,

    1. Set A = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11……}
    2. Set B = {} ⇢ Null set, since there are no numbers greater than 6 and less than 3.
    3. Set C = {10, 12, 14, 16, 18, 20, 22, 24}

    Question 3: Express the given information in the Set-Builder form.

    1. Numbers that are greater than 10 and less than 20.
    2. All Natural numbers greater than 25.
    3. Vowels in English Alphabet.

    Answer: 

    The Set-Builder form for the above information,

    1. A = {a: a∈ N and 10 < a < 20}
    2. B = {b: b∈ N and b > 25}
    3. C = {c: c is the vowel of English Alphabet}

    Question 4: Convert the following Sets given in Roster form into Set-Builder form.

    1. A = {b, c, d, f, g, h, j, k, l, m, n, p, q, r, s, t, v, w, x, y, z}
    2. B = {2, 4, 6, 8, 10}
    3. C = {5, 7, 9, 11,13, 15, 17, 19}

    Answer: 

    The Set- builder form for the above Sets,

    1. A = {a: a is a consonant of the English Alphabet}
    2. B = {b: b is an Even number and 2 ≤ b ≤10}
    3. C = {c: c is an odd number and 5 ≤ c ≤ 19}

    Question 5: Give an example of the following types of Sets in both Roster form and Set-builder form.

    1. Singular Set.
    2. Finite Set.
    3. Infinite Set.

    Solution:

    The Examples can be taken as per choice since there can be a infinite number of examples for any of the above Sets,

    • Singular Set

    Roster Form: A = {2}

    Set- builder form: A= {a: a∈N and 1<a<3}

    • Finite Set

    Roster Form: B = {0,1, 2, 3, 4, 5}

    Set-builder form: B = {b: b is a whole number and b<6}

    • Infinite Set

    Roster Form: C = {2, 4, 6, 8, 10, 12, 14, 16…..}

    Set- builder form: C= {c: c is a Natural and Even number}

    Question 6: What is the order of the given sets,

    1. A = {7, 14, 21, 28, 35}
    2. B = {a, b, c, d, e, f, g….x, y, z}
    3. C = {2, 4, 6, 8, 10, 12, 14……}

    Answer:

    The order of the set tells the number of element present in the Set.

    1. The order of Set A is 5 as it has 5 elements.
    2. The order of set B is 26 as the English Alphabet have 26 letters.
    3. The order of set C is infinite as the set has the infinite number of elements.

    Question 7: Express the given Sets in Roster form,

    1. A = {a: a = n/2, n ∈ N, n < 10}
    2. B = {b: b = n2, n ∈ N, n ≤ 5}

    Answer:

    Representing the above Set-builder sets in Roster form,

    1. A = {1/2, 1, 3/2, 2, 5/2, 3, 7/2, 4, 9/2}
    2. B = {1, 4, 9, 16, 25}
    See less
W3spoint99
  • 0
W3spoint99Begginer
Asked: December 27, 2024In:
  • 0

Explain – Biological Classification (NCERT Class 11 Chapter 2 Biological Classification).

biologicalbiologyclass 11classification
  1. Saralyn
    Saralyn Begginer

    Notes for NCERT Class 11 Chapter 2 Biological Classification: Biological classification is the process by which biologists group living organisms which, are classified on the basis of their similarity. Classification is essential for the convenient study of living organisms. It is required to identiRead more

    Notes for NCERT Class 11 Chapter 2 Biological Classification: Biological classification is the process by which biologists group living organisms which, are classified on the basis of their similarity. Classification is essential for the convenient study of living organisms. It is required to identify different varieties of organisms. It helps in the correct identification of many organisms. It leads to the evolution of organisms. It also establishes phylogenetic relationships among organisms. Carolus Linneuas was one of the scientists to classify organisms.

    NCERT Class 11 Biology Chapter 02 Biological Classification: The practice of classifying organisms based on shared characteristics is known as biological classification. Linnaeus proposed two areas of classification. He divided organisms into two kingdoms: the animal kingdom (Animalia) and the plant kingdom (Plantae). The classification of the two kingdoms had some disadvantages, such as the impossibility of distinguishing between eukaryotes and prokaryotes, unicellular and multicellular species, and photosynthetic and non-photosynthetic organisms. As a result, the field continued to grow and served as a primary example of R.H. Whittaker’s classification of the five domains or kingdoms.

    Biological Classification

    Two Kingdom Classification

    Two kingdom classification was given by a biologist, Carolus Linnaeus. He classified organisms into two kingdoms, i.e. Plantae (included all plants) and Animalia (included all animals).

    Disadvantages of Two Kingdom Classification

    This system didn’t distinguish between the following types of organisms-

    1. Eukaryotes and prokaryotes
    2. Unicellular and multicellular organisms
    3. Photosynthetic (green algae) and non-photosynthetic (fungi) organisms

    Five Kingdom Classification

    In 1969, R.H. Whittaker proposed the five-kingdom classification. He classified those five kingdoms as Monera, Protista, Fungi, Plantae, and Animalia. He primarily used the following criteria for classification:

    1. Cell structure
    2. Body organisation
    3. Mode of nourishment
    4. Reproduction
    5. Phylogenetic linkages or relationships
    Five Kingdom Classification

    Kingdom Monera

    Bacteria are the main members of this kingdom. Kingdom Monera is further divided into:

    1. Archaebacteria 
    2. Eubacteria or true bacteria
    Classification of Bacteria on the basis of Shape

    Archaebacteria

    They are special bacteria as they can withstand extreme environmental conditions because of their different cell wall structure. They can be:

    • Thermoacidophiles: They are found in the hot springs
    • Halophiles: They are found in the salty areas
    • Methanogens: They are found in the marshy areas/ gut of ruminant animals (production of biogas)

    Eubacteria or True Bacteria

    They have rigid cell walls and flagellum (locomotion), if motile. They can be photosynthetic autotrophs, chemosynthetic autotrophs and heterotrophs.

    • Photosynthetic Autotrophs: Cyanobacteria (blue-green algae, have chlorophyll a), Nostoc and Anabaena are their common examples. They are surrounded by a gelatinous sheath or mucilaginous covering, which protects them from wetting. They fix atmospheric nitrogen in specialised cells called heterocysts (significance)
    • Chemosynthetic Autotrophs: These are the bacteria which oxidise inorganic substances, e.g. nitrates, nitrites and ammonia and use the released energy for ATP production. They recycle nutrients, e.g. nitrogen, phosphorous, iron and sulphur (significance).
    • Heterotrophs: They are decomposers. Some of them are pathogens and some are beneficial as they are helpful in making curd from milk, producing antibiotics, and fixing atmospheric nitrogen in leguminous plants (significance).

    Heterocyst

    Reproduction in Bacteria

    They reproduce by asexual mode- binary fission, sexual mode- transfer of DNA and spore formation in unfavourable conditions.

    Binary Fission

    Mycoplasma

    They are the smallest organisms which lack cell walls. They can survive in the absence of oxygen (anaerobic). They cause diseases (pathogens).

    Kingdom Protista

    They are single-celled eukaryotes. They include:

    1. Chrysophytes
    2. Dinoflagellates
    3. Euglenoids
    4. Slime moulds
    5. Protozoans
    Classification of Protista Characteristic Features Examples
    Chrysophytes (chief producers in oceans) Their cell walls form two overlapping shells, which are fit together and embedded with silica which, makes them indestructible. So, cell wall deposits and their accumulation leads to ‘diatomaceous earth’. This soil can be used to polish things, and filter oils and syrups. Diatoms and golden algae (desmids)
    Dinoflagellates They show rapid multiplication and make the appearance of sea red (bioluminescence). Toxins released by them can kill other aquatic animals. Red dinoflagellates (Example: Gonyaulax)
    Euglenoids They have a pellicle protein-rich layer) which keeps them flexible Euglena
    Slime Moulds During suitable conditions, they form plasmodium and during unfavourable conditions,
    plasmodium differentiates and forms fruiting bodies (spores inside)    		 Acrasia, Plasmodiophorina
    Protozoans They are heterotrophs and live as predators or parasites. They are classified into four types Plasmodium

    Types of Protozoans and their Features/ Diseases Caused

    Protozoans Features/Diseases Caused Examples
    Amoeboid Protozoans They form pseudopodia to capture their prey. Some of them are parasites Amoeba, Entamoeba
    Flagellated Protozoans Sleeping sickness, a disease caused by the parasitic forms Trypanosoma
    Ciliated Protozoans Cilia (locomotion) and gullet, a cavity is present on the body Paramoecium
    Sporozoans Some species cause malaria Plasmodium

    Kingdom Fungi

    Fungi are multicellular and the how heterotrophic mode of nutrition (saprophytes/parasites/symbiotic- mycorrhiza). Some fungi are unicellular, e.g. yeast.

    Fungi

    Some Useful Fungi

    Mushrooms and yeast are the most valuable fungi. Mushrooms are edible and are a good source of proteins. Yeast is used to make bread and cheese. Penicillium fungi are used to produce antibiotics.

    Some Harmful Fungi

    Some fungi cause diseases in both plants and animals, e.g. wheat rust disease is caused by Puccinia fungus.

    Reproduction in Fungi

    There are three modes of reproduction in fungi, i.e. vegetative, asexual and sexual.

    • Vegetative Propagation: It takes place by fragmentation, fission and budding.
    • Asexual Reproduction: It takes place by conidia or sporangiospores or zoospores.
    • Sexual Reproduction: It takes place by oospores, ascospores and basidiospores.

    Stages of Sexual Reproduction in Fungi

    1. Plasmogay- It is the fusion of protoplasms between two motile or non-motile gametes.
    2. Karyogamy- It is the fusion of two nuclei.
    3. Meiosis in zygote, gives rise to haploid spores.

    In ascomycetes and basidiomycetes, the dikaryotic stage (n + n, i.e., two nuclei per cell) is formed, known as dikaryon and the phase is dikaryophase.

    Four Major Groups of Fungi

    Classification of Fungi Characteristic Features Examples
    Phycomycetes They grow on decaying wood in moist sites and obligate parasites on plant bodies Mucor, Rhizopus (bread
    mould fungi) and Albugo (parasitic fungi
    on mustard)
    Ascomycetes (sac-fungi) Neurospora is used in biochemical and genetic work. Some are edible, e.g. morels and truffles Penicillium, yeast, Aspergillus, Claviceps and Neurospora
    Basidiomycetes Some are edible, e.g. mushrooms. Mushrooms are rich in protein Agaricus (mushroom), Ustilago (smut) and Puccinia (rust
    fungus), Mushrooms, bracket fungi, puffballs
    Deuteromycetes They are known as ‘Imperfect Fungi’ because in this group, only asexual or vegetative phases are seen. Some fungi of this group are saprophytes or parasites while the majority are decomposers of litter, which aid in mineral cycling Alternaria, Colletotrichum and Trichoderma

    Kingdom Plantae

    All eukaryotic organisms that contain chlorophyll, usually known as plants, are classified as Plantae. A few species, like parasites and plants that feed on insects, are partially heterotrophic. Insectivorous plants include bladderwort and Venus fly traps, and parasites like Cuscuta feed on them. The eukaryotic structure of plant cells has large chloroplasts and a cell wall comprised primarily of cellulose. Algae, bryophytes, pteridophytes, gymnosperms, and angiosperms are all part of the plant kingdom.

    Alternation of Generation

    The haploid gametophytic and the diploid sporophytic phases of a plant’s life cycle alternate with one another. Various plant families have different haploid and diploid phase lengths and whether they are independent or reliant on others.

    Kingdom Plantae

    Kingdom Animalia

    They are multicellular and heterotrophic (show the holozoic mode of nutrition) eukaryotes. They lack cell walls. Almost, all the animals show locomotion. Sexual reproduction occurs by the fusion of male and female gametes which give rise to an embryo followed by repeated cell divisions.

    Viruses, Viroids, Prions And Lichens

    The differences between viruses, viroids and prions are given below:

    Viruses Viroids Prions
    They are oblique intracellular agents They are oblique intracellular agents They are the abnormal form of a cellular protein
    They have either DNA or RNA which is surrounded by a protein coat They consist of only RNA. The protein coat is absent They don’t possess DNA or RNA. Only protein coat is present

    Bacteriophage

    Bacteriophages are also known as phages. These are the viruses which infect and replicate in the bacterial cells.

    Bacteriophage

    Tobacco Mosaic Virus

    The tobacco mosaic virus (TMV) consists of single-stranded RNA. It infects tobacco plants and members of the family Solanaceae. The infection can cause some patterns like a mosaic, which shows mottling and discolouration on the surface of the leaves.

    Tobacco Mosaic Virus

    Lichens

    The close association of fungus and algae form lichens. They are found in a pollution-free environment. Lichens are used in deodorant, pH papers, insense-sticks, toothpaste and perfumes. The fungal component is known as mycobiont and the algal component is known as phycobiont.

    FAQs on Biological Classification

    Q1: What are the Commercial Applications for Heterotrophic Bacteria and Archaea?

    Answer:

    Heterotrophic Bacteria: They help with nitrogen fixation, ammonification and nitrification. In addition, Rhizobium bacteria, they maintain soil fertility. Other members produce dairy products such as cheese and cottage cheese. Archaebacteria: Methanogens in animal feces produce biogas.

    Q2: Write Some Plant like and Animal-like Features of Euglena.

    Answer:

    Plant-like features are:

    • Euglena has plastids which help in photosynthesis
    • Some of the species of euglena have carotenoid pigments, which give it red colour

    Animal-like features are:

    • Euglena doesn’t have a cell wall
    • Flagella are present for locomotion

    Q3: What Function Do Fungi Play in Our Daily Lives?

    Answer:

    Mushroom and yeast are the most useful fungi. Mushrooms are edible and are a good source of proteins. Yeast is used to make bread and cheese. Penicillium fungi is used to produce antibiotics.

    See less