Plant Physiology: IV. Plant Reproduction

Total Questions: 28

1. To study meiosis in plants, the best part would be [M.P.P.C.S. (Pre) 2017]

(a) Shoot apex
(b) Root apex
(c) Anthers
(d) Leaf cells

Correct Answer: (c) Anthers

Solution:To study meiosis in plants, the best part would be anthers. In this, the pollination is formed after the meiosis which is actually immature male gametophyte. Stamens are in the form of male genital and carpels are in the form of egg-born female.

2. Which of the following statements is/are correct regarding vegetative propagation of plants? [I.A.S. (Pre) 2014]

Vegetative propagation produces clonal population.
Vegetative propagation helps in eliminating the virus.
Vegetative propagation can be practiced most of the year.

Select the correct answer using the code given below.

(a) 1 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3

Correct Answer: (c) 1 and 3 only

Solution:Vegetative or clonal propagation is an asexual reproduction in which successive mitosis of specialized vegetative propagules (as bulbs, corms, tubers, cuttings, buds and apomictic seeds) develop new plants and results in a clonal population. Therefore statement 1 is correct. Viruses are transmitted from plant to plant in a number of ways such as vegetative propagation. Viral diseases could be transferred through vegetative parts. So the statement 2 is incorrect. Vegetative propagation can be practised most of the year. Hence, statement 3 is correct.

3. The practice of gootee in plants is used for the purpose of: [U.P. R.O./A.R.O. (Pre) 2021]

(a) Control of insects
(b) For vegetative propagation
(c) Germination of seeds
(d) Weed control

Correct Answer: (b) For vegetative propagation

Solution:Gootee in plants is a method of vegetative propagation of plants that requires the rooting of aerial stems when connected to the parent plant. It is also named as air layering, marcotting, pot layerage, marcottage and circumposition.

4. With reference to the current trends in the cultivation of sugarcane in India, consider the following statements: [I.A.S. (Pre) 2020]

A substantial saving in seed material is made when 'bud chip settlings' are raised in a nursery and transplanted in the main field.
When direct planting of setts is done, the germination percentage is better with single-budded setts as compared to setts with many buds.
If bad weather conditions prevail when setts are directly planted, single-budded setts have better survival as compared to large setts.
Sugarcane can be cultivated using settlings prepared from tissue culture.

Which of the statements given above is/are correct?

(a) 1 and 2 only
(b) 3 only
(c) 1 and 4 only
(d) 2, 3 and 4 only

Correct Answer: (c) 1 and 4 only

Solution:With reference to the current trends in the cultivation of sugarcane in India:

The 'bud chip' method for cane plantation reduces the mass and enables quick multiplication of seeds. This method has proved to be more economical and convenient than the traditional way of planting two or three bud sets.
The returns are relatively better and a substantial saving in seed material is made when 'bud chip settlings' are raised in a nursery and transplanted in the main field.
When direct planting of setts is done, it is found that the germination percentage is better with many-buds setts as compared to single-budded setts.
When setts are directly planted, large setts have better survival under bad weather than single-budded setts.
Planting material for vegetative propagation of sugarcane includes whole cane, setts having of single buds to many buds, setts prepared in nursery or setts prepared from tissue culture.
Hence, among the given statements, only statements 1 and 4 are correct.

5. Sugarcane is a : [Jharkhand P.C.S. (Pre) 2023]

(a) short day plant
(b) long day plant
(c) day neutral plant
(d) photo insensitive plant

Correct Answer: (a) short day plant

Solution:Sugarcane plants usually bloom in winter, when days are shorter. It is therefore a short day plant as classified by photoperiodism. In general, sugarcane is termed an intermediate daylength plant with quantitative short-day behavior.

6. With reference to crop rotation, which of the following statement is/are correct? [U.P. R.O./A.R.O. (Pre) 2021]

Deep rooted crops should be followed by the same type of crop.
Legume must be followed by a non-legume.

Select the correct answer using the codes given below :
Code :

(a) Only 1
(b) Only 2
(c) Both 1 and 2
(d) Neither 1 nor 2

Correct Answer: (b) Only 2

Solution:Crop rotation refers to the cultivation of different crops successively, in line with changing seasons. The order and area of crops to be grown is accordingly patterned for optimizing soil nutrients and water, controlling pests and suppressing weeds. An effective crop rotation system requires right selection of crops that adjust well with the space, sunlight and soil in rooftop garden. General principles that guide crop rotation are listed hereafter :

Leguminous crops should be followed by non-leguminous crops.
The crops with tap roots (dicots) should be grown after those which have fibrous root system (monocots).
Slow-growing crops which are more vulnerable to weeds should be grown immediately after weed-suppressing crops in a rotation system.
Closely related species should not be grown successively as they act as alternate hosts for insects, pests and diseases.
Deep rooted crops should be succeeded by shallow rooted crops.
Crops susceptible to soil borne pathogens and parasitic weeds should be followed by tolerant crops.

7. Given below are two statements, in which one is labelled as Assertion (A) and the other as Reason (R). [U.P. R.O./A.R.O. (Pre) 2023]

Assertion (A): Pulses, when included in intercropping with cereals, act as complimentary crops.

Reason (R): Pulses with tap root system, do not compete for nutrients and moisture with cereals having fibrous root system.

Select the correct answer from the code given below :
Code :

(a) (A) is true but (R) is false.
(b) (A) is false but (R) is true.
(c) Both (A) and (R) are true but (R) is not correct explanation of (A).
(d) Both (A) and (R) are true and (R) is correct explanation of (A).

Correct Answer: (c) Both (A) and (R) are true but (R) is not correct explanation of (A).

Solution:Intercropping is the practice of growing two or more crops in proximity. Pulses are generally intercropped with coarse cereals and oilseeds under rainfed condition in our country. Pulses, when included in intercropping with cereals, act as complimentary crops. The slow initial growth habit and deep tap root system makes these crops more suitable for intercropping with cereals and oilseed crops than any other crop. Pulses with tap root system, do not compete for nutrients and moisture with cereals having fibrous root system. The tap root system allows plants to anchor better, get sources of minerals and water from further into the ground than fibrous-rooted plants. Apart from increasing profitability and resource use efficiency, pulses as intercrop act as safeguard under unprecedented moisture stress condition. Pulses can contribute significantly to achieve the twin objectives of increasing productivity and improving the sustainability of rice and wheat based cropping systems. The pulses grown together with or before a cereal crop can reduce and sometimes substitute the need of nitrogen application as well. Hence, both (A) and (R) are true but (R) is not the correct explanation of (A).

8. Clonal selection can be used in - [U.P.P.C.S. (Mains) 2009]

(a) Groundnut
(b) Mustard
(c) Wheat
(d) Potato

Correct Answer: (d) Potato

Solution:The procedure of selection used for asexually propagated crops is known as clonal selection since the selected plants are used to produce new clones. This method is used in the production of potatoes.

9. A plant bud is - [56th to 59th B.P.S.C. (Pre) 2015]

(a) An embryonic shoot
(b) An embryonic leaf
(c) An endosperm
(d) A seed

Correct Answer: (a) An embryonic shoot

Solution:In botany, a bud is an undeveloped or embryonic shoot and normally occurs in the axil of a leaf or at the tip of the stem.

10. Embryo is found in - [53rd to 55th B.P.S.C. (Pre) 2011]

(a) Flowers
(b) Leaves
(c) Seeds
(d) Buds

Correct Answer: (c) Seeds

Solution:The embryo along with other cells from the mother plant develops into the seed for the next generation, which, after germination, grows into a new plant.

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