Tag: evs

Quizzes (439) Questions (4580)

Questions Related to evs

Multiple choice evs forests: our lifeline food material and source sources of food and food habits of animals seed dispersal

The decomposers in the forest perform 

  1. Production of the plants

  2. Decomposition of the plants and animals

  3. Breakdown of the forests

  4. All of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Decomposers are saprotrophs, which decompose the organic remains of plants and animals by secreting extracellular digestive enzymes. Due to degradation of organic remains, decomposers are also called reducers. Heterotrophic bacteria and saprophytic fungi are the important organisms which usually act as decomposers. Thus, the correct answer is option B.

Multiple choice evs forests: our lifeline food material and source sources of food and food habits of animals seed dispersal

Assertion : Interspecific hybridization often fails to form normal embryos.

Reason : Such embryos can germinate in culture conditions.

  1. If both assertion and reason are true and the reason is the correct explanation of the assertion.

  2. If both assertion and reason are true but reason is not the correct explanation of the assertion.

  3. If assertion is true but reason is false.

  4. If the assertion and reason both are false.

  5. If assertion is false but reason is true.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Interspecific hybridization often fails to form normal embryos due to genetic incompatibility. However, the reason provided is not the cause of the failure; rather, it is a technique used to rescue such embryos.

Multiple choice evs forests: our lifeline food material and source sources of food and food habits of animals seed dispersal
Assertion:Methyl mercury highly persistent kind of pollutant that accumulates in food chain 
Reason: Mercury pollution is responsible for Minamata disease

  1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion

  2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion

  3. If the assertion is true but the reason is false

  4. If both the assertion and reason are false

  5. If the assertion is false but reason is true
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Methyl mercury is a persistent pollutant that biomagnifies in food chains, and mercury poisoning is indeed the cause of Minamata disease. These are two distinct facts about mercury, so the reason does not explain the assertion.

Multiple choice evs forests: our lifeline food material and source sources of food and food habits of animals seed dispersal

Which among the following always decreases in a Food chain across tropic levels?

  1. Number

  2. Accumulated chemicals

  3. Energy

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

According to the 10% law of energy transfer, energy is lost as heat at each trophic level. Therefore, the amount of available energy always decreases as you move up the food chain.

Multiple choice evs forests: our lifeline food material and source sources of food and food habits of animals seed dispersal

Which organism will be affected in the absence of the decomposers?

  1. Plants

  2. Animals

  3. Insects

  4. All of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Decomposers are the organisms that play a critical role by breaking down and decomposing the body and release the element back to nature for other organisms. Thus they help in recycling the nutrients in the atmosphere. They also act as the cleaning agent of the environment because without them dead organisms will pile up. Thus in their absence all the organisms i.e., plants, animals, and insects will be affected. Thus, the correct answer is option D.

Multiple choice evs light and shadow dual nature of light nature and sources of light theories on light

Light of wavelength $\lambda $ from a point source falls on a small circular obstacle of diameter d. Dark and bright circular rings around a central bright spot are formed on a screen beyond the obstacle. The distance between the screen and obstacle is D. Then , the condition for the formation of rings, is

  1. $\sqrt { \lambda } \approx \cfrac { { d } }{ 4D } $
  2. $\lambda \approx \cfrac { { d }^{ 2 } }{ 4D } $
  3. $d\approx \cfrac { { \lambda }^{ 2 } }{ D } $
  4. $\lambda \approx \cfrac { D }{ 4 } $
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The condition for diffraction rings around a circular obstacle (Poisson spot) is related to the Fresnel zone plate condition, where lambda is approximately d^2 / 4D.

Multiple choice evs light and shadow dual nature of light nature and sources of light theories on light

Which of the following is incorrect?

  1. A thin convex lens of focal length ${f} _{1}$ is placed in contact with a thin concave lens of focal length ${f} _{2}$. The combination will act as convex lens if ${f} _{1}<{f} _{2}$
  2. Light on reflection at water-glass boundary will undergo a phase change of $\pi$

  3. Spherical aberration is minimized by achromatic lens

  4. If the image of distant object is formed in front of the retina then defect of vision may be myopia
Reveal answer Fill a bubble to check yourself
B Correct answer