Plant Physiology: IV. Plant Reproduction

Total Questions: 28

21. Consider the following kinds organisms – [I.A.S. (Pre) 2012]

Bat
Bee
Bird

Which of the above is/are pollinating agent/agents?

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

Correct Answer: (d) 1, 2 and 3

Solution:Pollination is the act of transferring pollen grains from male anther of a flower to the female stigma. It is a prerequisite for fertilization. Fertilization allows the flower to develop fruits and seeds. Bees are the most important pollinating agent. Pollination by bees and butterflies often occurs in the flowers which bloom in the day time. Hummingbird-pollinated flowers appear in warm colours like red, yellow and orange. Bat is also a pollinating agent of many flowers. However the number of animals - pollinated flowers are not so high, some of them are found in the southern hemisphere.

22. Pollination is best defined as : [67th B.P.S.C. (Pre) (Re. Exam) 2022]

(a) transfer of pollen grain from anther to stigma
(b) germination of pollen grains
(c) growth of pollen tube in ovule
(d) visiting flowers by insects
(e) None of the above/More than one of the above

Correct Answer: (a) transfer of pollen grain from anther to stigma

23. Seed that is changed every year is known as - [U.P.P.C.S. (Mains) 2010]

(a) Breeder seed
(b) Certified seed
(c) Foundation seed
(d) Hybrid seed

Correct Answer: (d) Hybrid seed

Solution:Hybrid seed is changed every year. In agriculture and gardening, hybrid seed is seed produced by cross pollinated plants. Hybrid seed production is predominant in agriculture and home gardening.

Breeder Seed: This is the seed directly controlled by the plant breeder or the institution where the breeding program is carried out. It's the source for the initial production of foundation seed.

Foundation Seed: This is the progeny of breeder seed, meaning it's produced from breeder seed or from previous generations of foundation seed. It's produced under the supervision of qualified plant breeders and is a step in the process of increasing seed supply for commercial use.

Certified Seed: This is the progeny of foundation seed, and its production is overseen and certified by a certification agency to ensure it meets specific standards for genetic identity and purity.

24. Consider the following events of seed multiplication stages and arrange these in correct chronological order from earliest stage to last. [U.P. R.O./A.R.O. (Pre) 2023]

I. Breeder seed
II. Foundation seed
III. Certified seed
IV. Nucleus seed

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

(a) III, I, IV, II
(b) II, III, I, IV
(c) II, IV, III, I
(d) IV, I, II, III

Correct Answer: (d) IV, I, II, III

Solution:The correct chronological order of events of seed multiplication stages from earliest stage to last, is as follows :
Nucleus seed → Breeder seed → Foundation seed → Certified seed.
Hence, option (d) is the correct answer.

25. In a bisexual flower, if androecium and gynoecium mature at different times, the phenomenon is known as : [I.A.S. (Pre) 2002]

(a) Dichogamy
(b) Herkogamy
(c) Heterogamy
(d) Monogamy

Correct Answer: (a) Dichogamy

Solution:In a bisexual flower, if androecium and gynoecium mature at different time the phenomenon is known as dichogamy. It is of two types (1) Protandry (2) Protogyny. Protogyny is a condition of flower in which female parts mature before the male ones, while protandry is the condition in which male part of flower mature before the female ones.

26. Which of the following genomic conditions is found in commercial edible wheat? [Jharkhand P.C.S. (Pre) 2023]

(a) AB genome
(b) ABC genome
(c) ABCD genome
(d) ABD genome

Correct Answer: (d) ABD genome

Solution:

ABD genome (AABBDD) is found in commercial edible wheat (i.e., Bread wheat; Triticum aestivum).

27. How many chromosomes are found in the endosperm of maize? [Jharkhand P.C.S. (Pre) 2023]

(a) 20
(b) 30
(c) 40
(d) 23

Correct Answer: (b) 30

Solution:In maize, meiocyte contains 20 chromosomes and gamete has 10 chromosomes. Endosperm is triploid in maize. Hence, the number of chromosomes in the endosperm (triploid tissue that nourishes embryo) of maize is 30.

28. Which component of plants receives stimulus for flowering? [Jharkhand P.C.S. (Pre) 2013]

(a) Stems
(b) Branches
(c) Leaves
(d) Roots

Correct Answer: (c) Leaves

Solution:The stimulus for flowering which are light, energy and carbon dioxide are received by the leaves of a plant. The leaves are the sites of food production for the flowering plant. Apart from this, florigen, the flowering hormone or stimulus is also produced in leaves.

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