Plant Physiology: IV. Plant Reproduction

Total Questions: 28

11. Match List-I with List-II and select the correct answer by using the codes given below the lists : [I.A.S. (Pre) 1998]

List-I	List-II
A. Fruit	1. Ovule
B. Seed	2. Leaf
C. Wood	3. Stem
D. Starch	4. Ovary

Code :

Code	A	B	C	D
(a)	2	1	3	4
(b)	4	1	3	2
(c)	2	3	1	4
(d)	4	3	1	2

Correct Answer: (b)

Solution:The correctly matched order is :
Fruit - Ovary
Seed - Ovule
Wood - Stem
Starch - Leaf

12. Plants are formed like parent plant from - [39th B.P.S.C. (Pre) 1994]

(a) Seeds
(b) Stem cut
(c) None of these
(d) Both of these

Correct Answer: (b) Stem cut

Solution:Plants are propagated by two methods –

Sexual propagation or seed propagation.
Asexual or vegetative propagation. Vegetative propagation is a form of asexual reproduction of a plant. Only one plant is involved and offspring is the result of one parent, The new plant is genetically identical to the parent. In this process, new organism arises from any vegetative part of the parent (root, stem, leaf etc.) and possesses exactly the same characteristics of the parent plant. The purity of plants is maintained in vegetative propagation which is not possible in sexual reproduction. Stem cutting, grafting, layering, etc. are common artificial methods of vegetative propagation.

13. Stem cutting is done generally to grow - [39th B.P.S.C. (Pre) 1994]

(a) Banana
(b) Sugarcane
(c) Mango
(d) Cotton

Correct Answer: (b) Sugarcane

Solution:Botanically, Sugarcane belongs to the Andropogoneae tribe of the family Gramineae. Sugarcane plants are propagated by stem cutting. Stem cutting is segmented parts of the stem or entire stems detached from the main branch. Mango and cotton are generally grown from seeds while suckers are used as the planting material for banana. Sucker in banana arises from the root and is an extension of the rhizome as a lateral root. Some farmers also practice tissue culture for banana cultivation using seedlings developed through tissue culture. Rhizomes and peepers are the other planting materials used for banana cultivation.

14. Consider the following plants : [I.A.S. (Pre) 2002]

Bougainvillea
Carnation
Cocoa
Grapes

Which of these plants are propagated by stem cuttings ?

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

Correct Answer: (d) 1, 2, 3 and 4

Solution:Propagation of plants by stem cuttings is the most popular plant propagation method for woody shrubs and ornamental plants. This is also a good technique for house plants. Some of the plants propagated by stem cuttings are Sugarcane, grapes, Rose, Cocoa, Carnation, Duranta, Bougainvillea, etc. Although in plants like Cocoa, propagation by seeds is also popular.

15. Consider the following statements: [I.A.S. (Pre) 2009]

Sweet orange plant is propagated by grafting technique.
Jasmine plant is propagated by layering technique.

Which of the statement(s) given above is/are correct?

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

Correct Answer: (c) Both 1 and 2

Solution:Layering is a way to grow new plants as in case of Jasmine, (from existing plants without having to take any cuttings). In a nutshell, bury part of a stem or branch in the soil and new roots and shoots will form. Grafting or graftage is a horticultural technique whereby tissues from one plant are inserted into those of another so that the two sets of vascular tissues may join together. Sweet orange plant is propagated by this technique.

16. The most important part of the plant in term of its life cycle is- [47th B.P.S.C. (Pre) 2003]

(a) Flower
(b) Leaf
(c) Stem
(d) Root

Correct Answer: (a) Flower

Solution:The flower is the most important part of the plant in term of its life cycle. The biological function of a flower is to mediate the union of male and female gametes in order to produce seeds. The process begins with pollination followed by fertilization and continues with the formation and dispersal of the seed.

17. Which of the three circumstances among these are most necessary in the germination of single seed plants? [Uttarakhand U.D.A./L.D.A. (Pre) 2003]

(a) Soil, water, oxygen
(b) Water, proper temperature, oxygen
(c) Proper temperature, oxygen, CO₂
(d) Temperature, oxygen, light

Correct Answer: (b) Water, proper temperature, oxygen

Solution:Water, proper temperature and oxygen are the most required substances/circumstances for the germination of seed, while the sunlight is not essential. There are two types of germination of seed in plants - epigeal and hypogeal.

Water is needed to activate enzymes within the seed and to help dissolve stored food reserves, enabling the embryo to resume growth.

A suitable temperature range is required for enzymatic reactions to occur efficiently, promoting growth.

Oxygen is essential for respiration, providing the energy the seed needs to germinate.

While light is crucial for photosynthesis in the growing plant, it's not directly necessary for the germination process itself. Many seeds germinate perfectly well in the dark.

18. Which one is not required for the germination of seed? [U.P.P.C.S. (Pre) 1990]

(a) Light
(b) Humidity
(c) Proper temperature
(d) Oxygen

Correct Answer: (a) Light

Water is needed to activate enzymes within the seed and to help dissolve stored food reserves, enabling the embryo to resume growth.

A suitable temperature range is required for enzymatic reactions to occur efficiently, promoting growth.

Oxygen is essential for respiration, providing the energy the seed needs to germinate.

While light is crucial for photosynthesis in the growing plant, it's not directly necessary for the germination process itself. Many seeds germinate perfectly well in the dark.

19. Censer mechanism of dispersal of seeds is found in : [U.P.P.C.S. (Mains) 2010]

(a) Pea
(b) Poppy
(c) Cotton
(d) Maize

Correct Answer: (b) Poppy

Solution:Seed dispersal is the movement or transport of seeds away from the parent plant. Plants have very limited mobility and consequently rely upon a variety of dispersal vectors to transport their propagules, including both abiotic and biotic vectors. Censer mechanism of dispersal of seeds is found in poppy.

20. Transfer of pollen grains from the anther to stigma of another flower of the same plant is called [M.P.P.C.S. (Pre) 2019]

(a) Autogamy
(b) Geitonogamy
(c) Xenogamy
(d) None of the above

Correct Answer: (b) Geitonogamy

Solution:Transfer of pollen grains from the anther to stigma of another flower of the same plant is called geitonogamy. It is a type of self-pollination.

Autogamy: This occurs when pollen from a flower's anther is transferred to the stigma of the same flower. It's a form of self-pollination, also known as self-fertilization.

Xenogamy: This is cross-pollination where pollen is transferred from the anther of one flower to the stigma of a flower on a different plant. It's the most common type of cross-pollination, promoting genetic diversity,

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