Questions Related to evs

Multiple choice evs life within the seed introduction to plant organs and germination seed to plants germination of seeds developmental journey of seed

Consider the following statements.
a. The seeds of Zea mays would germinate immediately after falling from the plant if favourable conditions of moisture, temperature and aeration are available.
b. Seed-coat dormancy is exhibited by Cassia and Gossypium
Which of the statements given is/are correct?

  1. $1$ only
  2. $2$ only
  3. Both $1$ and $2$
  4. Neither $1$ nor $2$
Reveal answer Fill a bubble to check yourself
C Correct answer
Multiple choice evs seeds and seeds introduction to plant organs and germination seed to plants germination of seeds

Occasionally, in some seeds such as ______(A) ___, remnants of nucellus are also persistent.This residual, persistent nucellus is the __(B)__________.

  1. (A) Castor and beet (B) Endopserm

  2. (A) Castor and beet (B) Carucele

  3. (A) Maize and rice (B) Aleurone layer

  4. (A) Black pepper and beet (B) Perisperm

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In some seeds such as black pepper and beet, remnants of the nucellus persist persistently. This residual nutritive nucellar tissue is known as the perisperm.

Multiple choice evs life within the seed introduction to plant organs and germination seed to plants germination of seeds developmental journey of seed

State whether the following statements are true or false.
Seedlings grown for a few days in the dark often have lesser fresh weight and greater dry weight than those kept in light for a comparable period.

  1. True

  2. False

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

For the development of any seedling or plants, both light and dark phases are required for proper growth. The seedlings that are growing requires light as the carbon sources in them and the other nutrients are present in its complete amount but when they are placed in the darkness they are unable to perform certain functions so there is less production of nutrients resulting in lower fresh weight. Thus, the light phase is the phase on which growth of the plant is dependent upon. 

So, the correct statement is 'False'. 

Multiple choice evs seeds and seeds introduction to plant organs and germination seed to plants germination of seeds

State whether the following statements are true or false.
A dry pea seed will have more dry weight than a germinated one.

  1. True

  2. False

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The dry seeds of the pea have more dry weight as all the moisture in the seeds got absorbed and becomes hard due to the loss of water. In the germinated seed, more water is present so its fresh weight will be higher than the dry seed. Fresh weight is the weight of the living part of the plant while dry weight is the weight of the dry plant part.

So, the correct statement is 'True'. 

Multiple choice evs soil- our life horizons of soil soil - formation and profile soil-nature

Rate of decomposition depends upon

  1. Chemical composition of detritus

  2. Temperature

  3. Soil moisture and soil pH

  4. All of these

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Rate of decomposition of detritus depends upon chemical mature of detritus, temperature, soil moisture and soil pH. A soil temperature of 25oC and more hastens decomposition. A low temperature of less than 10oC reduces the rate of decomposition. Moisture is essential for decomposition. Excessive moisture also impedes decomposition probably due to anaerobiosis. Neutral and slightly alkaline soils are rich in detritivores, earthworms and decomposer microbes. Acidity decreases the number of detritivores and earthworms. Soil with a small amount of lignin/chitin/cellulose and rich in nitrogen and water-soluble substances(like sugars), decomposes rapidly.

So, the correct answer is 'All of these'.

Multiple choice evs soil- our life horizons of soil soil - formation and profile soil-nature

Which of the following provides shelter for many living organisms?

  1. A-Horizon

  2. B-Horizon

  3. C-Horizon

  4. None of the above

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

As we know, the soil is made up of many layers. These layers are called horizons. The topmost among these layers is A horizon. It is the layer parallel to the soil surface. It is rich in organic matter. It also contains humus, which is necessary for the proper growth of plants. Thus, we can say that A horizon has many necessary ingredients to support the plant and animal life.

So, option A 'A Horizon" is the correct answer.

Multiple choice evs soil- our life horizons of soil soil - formation and profile soil-nature

Which of the following layer has more minerals?

  1. A-Horizon

  2. B-Horizon

  3. C-Horizon

  4. Both A and C

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The horizon B is also known as the layer of subsoil. It is light brown in colour. it has lots of iron and clay minerals accumulated inside it. this layer contains more soluble minerals and clay inside it and so the plant roots reaching here can get maximum mineral content for their growth and development.

So, option B "B Horizon" is the correct option.

Multiple choice evs soil- our life horizons of soil soil - formation and profile soil-nature

Soil contains 

  1. Air and water

  2. Water and plants

  3. Minerals, organic matter, air and water

  4. Water, air and plants

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Soil is one of the most important abiotic resources of the environment. It provides habitat to a vast number of living organisms. It holds the roots of plants and trees. It provides the necessary nutrients to the plants when their roots absorb water from the soil, along with minerals and organic matter present in the form of humus in the soil. Soil also has spaces between its particles, providing space for air and water to percolate into it. So, the soil is a mixture of minerals, organic matter, air, and water.

So, option C "Minerals, organic matter, air and water" is the correct answer.