Origin and Evolution of Life — BIOLOGY STD 12 Science — Question

Read the following and answer any four questions from (i) to (v) given below:
Green manuring is the fanning practice where a leguminous plant which has derived enough benefits from its association with appropriate species of Rhizobium, is ploughed into the field soil and then a non-legume is sown and allowed to get benefitted from the already present nitrogen fixer. Some legumes, such as, Crotolaria juncea, Sesbania rostrata, Lencaena leucocephala, etc. are used as green manure. Rhizobia, that fix atmospheric nitrogen in the form of nitrate, live in the roots ofleguminous plants. These nutrients are used by non-leguminous plants through the practice of green manuring.

1. Green manures mainly provide nutrient enriched in:

1. Magnesium.
2. Sulphur.
3. Nitrogen.
4. Both (a) and (b).

2. Which of the following plants is used as green manure in crop fields?

1. Saccharum.
2. Dichanthium.
3. Phyllonthus.
4. Crotolaria.

3. Green manure plants belong to the Family:

1. Lamiaceae.
2. Papilionaceae.
3. Liliaceae.
4. Poaceae.

4. Due to excess use of chemical fertilisers rich in nitrate, ________ disease occurred in children.

1. Jaundice.
2. Septicemia.
3. Methemoglobinemia.
4. Botulism.

5. A green manure is:

1. Rice.
2. Maize.
3. Sorghum.
4. Sesbania.

Distinguish between: Homologous organs and Analogous organs.

A regulatory body working under MoEF for the release of transgenic crop is ____________:

1. NBPGR
2. NSC
3. NIPGR
4. GEAC

Read the following and answer any four questions from (i) to (v) given below:
Many adaptations are found in flowers to achieve certain kind of pollination. The pollination achieved by insects is known as entomophily. The given diagram shows the cross-section of an anther of an insect pollinated flower.

1. Which of the following is/ are the function(s) of structure Y?

1. To carry waste products away from the anther.
2. To supply oxygen to the cells of the anther.
3. To transport food and mineral salts to the anther.
4. To supply water to the anther.

1. Conly.
2. C and D only.
3. A, B and D only.
4. A, B, C and D.

2. Which of the following most accurately describes the structures found in compartment X?

1. They contain two haploid nuclei resulting from meiosis.
2. They contain two haploid nuclei resulting from mitosis.
3. They contain two haploid male gametes, resulting from mitosis.
4. They contain a vegetative nucleus and pollen tube nucleus.

3. Which of the following is a distinctive characteristic of insect-pollinated flower?

1. All of them have nectar guides on their flowers.
2. They produce sugary fruit.
3. Their pollen grains tend to have rough surfaces.
4. They produce abundant quantities of pollen to make up for pollen grains that might be removed by the wind.

4. Which of the following are likely characteristics of the structures found in X and stamens of this plant?

S. No	Structure of X	Stamens
(a)	Abundant and light	Pendulous
(b)	Rough surfaces	Non-pendulous
(c)	Light and sticky	Pendulous
(d)	Coarse and sticky	Protrude outside the flower

5. Spiny or sticky pollen grains and large, attractively coloured flowers are associated with:

1. Hydrophily.
2. Entomophily.
3. Ornithophily.
4. Anemophily.

Distinguish between: Morula and Blastula.