Tag: evs

Questions Related to evs

Most seeds go through ____ period before germination.

  1. Cold

  2. Hot

  3. Solid

  4. None of the above


Correct Option: A
Explanation:

Most seeds go through a cold period before germination. Helps prevent seeds from sprouting as soon as they mature.

Deeply sown seeds do not germinate and do not come up over due to the deficiency of ...................

  1. Nutrients

  2. Water

  3. Oxygen

  4. Both B and C


Correct Option: D
Explanation:

Soil is ploughed before seeds are sown. It is done to ensure the supply of oxygen in soil. Aerated soils can only support the growth of plants. Thus, if the seeds are sown deeply it will not germinate.

The most important external factor for seed germination is

  1. Light

  2. Soil

  3. Oxygen

  4. Water


Correct Option: D
Explanation:

Water, air and suitable temperature are necessary for seed germination. Water is necesssary for germination because food is stored in the seeds in dry condition, but the developing embryo cannot utilize this dry food. Food can be utilized in liquid form only and seeds can utilize only dissolved oxygen. Excess water stops germination because once all the dissolved oxygen is utilised by the seed, further germination is not possible as the life supporting oxygen is now lacking. So, the correct answer is 'Water'.

Seeds of tomato do not germinate in its pullp due to

  1. Presence of ferulic acid

  2. Presence of excess salts

  3. Absence of oxygen

  4. Presence of ABA


Correct Option: A
Explanation:

In general seeds within the fruit do not germinate due to germination inhibitory effects of fruit pulp except viviparous germination. Tomato seeds loose viability and germination percentage up to 50% within one year after fresh extraction. Ferulic acid is a growth inhibitor in tomato. So, the correct answer is 'Presence of ferulic seed'.

A seed which does not require oxygen for germination is

  1. Pea

  2. Rice

  3. Typha

  4. Both B and C


Correct Option: D
Explanation:

All seeds need water, oxygen, and proper temperature in order to germinate. Some seeds require proper light also. Some germinate better in full light while others require darkness to germinate. Rice seeds and typha seeds are able to germinate anaerobically by means of coleoptile elongation. Pea seeds require oxygen to germinate. So, the correct answer is ‘Both B and C’.

Seeds placed deep in the soil do not germinate because they are

  1. Unable to get sufficient oxygen

  2. Without sufficient food to bring the seedling to the surface

  3. Under pressure of overlying soil layers

  4. Unable to get light


Correct Option: A
Explanation:

During germination rapid cell division takes place. Energy is required for cell division. This energy is obtained from oxidation. The oxygen required for oxidation is supplied by the air. So, air is necessary for seed germination. Seeds placed deep in the soil do not germinate because they are unable to get sufficient oxygen. So, the correct answer is 'Unable to get sufficient oxygen'.

Freshly shed seeds can germinate immediately under favourable conditions in

  1. Xanthium

  2. Pisum sativum

  3. Zea mays

  4. Both B and C


Correct Option: D
Explanation:

A. Xanthium has seed dormancy due to present of germination inhibitors like abscisic acid, phenolic acid, ferulic acid, coumarin, short fatty acids and cyanogenic chemicals. So, it  won’t germinate in the presence of favorable condition.

B. Pisum sativum- Don’t have germination inhibitors. So, it germinate in the presence of favorable condition.


C. Zea mays- Don’t have germination inhibitors. So, it germinate in the presence of favorable condition.

So, the correct answer is ‘Both B and C’.

Which are the external conditions required for seed germination?

  1. Oxygen, carbon dioxide and suitable temperature

  2. Oxygen, light and suitable temperature

  3. Light, moisture and suitable temperature

  4. Oxygen, moisture and suitable temperature


Correct Option: D
Explanation:

Conditions necessary for germination: Water, air and suitable temperature are necessary for seed germination.

Water is necesssary for germination because food is stored in the seeds in dry condition, but the developing embryo cannot utilize this dry food. Food can be utilized in liquid form only and seeds can utilize only dissolved oxygen. Excess water stops germination because once all the dissolved oxygen is utilised by the seed, further germination is not possible as the life supporting oxygen is now lacking.

During germination rapid cell division takes place. Energy is required for cell division. This energy is obtained from oxidation. The oxygen required for oxidation is supplied by the air. So, air is necessary for seed germination.

Suitable temperature is necessary because low temperature retards the embryo activity and high temperature destroys the delicate embryo tissue. 

So, the correct answer is 'Oxygen, moisture and suitable temperature'

A seed which is unable to germinate in the presence of light is ___________.

  1. Viscum

  2. Onion

  3. Bean

  4. Maize


Correct Option: B

Which one is essential for good germination in pea?

  1. $ O _2 $

  2. $ H _2 $

  3. $ N _2 $

  4. $ CO _2 $


Correct Option: A
Explanation:

Air (oxygen) is necessary for seed germination(Pea seed). During germination rapid cell division takes place. Energy is required for cell division. This energy is obtained from oxidation. The oxygen required for oxidation is supplied by the air. So, air is necessary for seed germination. So, the correct answer is ‘Oxygen’.