Top 100+ Sexual Reproduction in Flowering Plants - Biology Questions and Answers For NEET 2024 Exam Preparation

Q1. Which one of the following is correct for animal pollinated plants?

1. To harvest the rewards from the flower, animal come in contact with anther and stigma.
2. Nectar and pollen grains are usual floral rewards.
3. Animal carrying pollen when come in contact with stigma, it brings about pollination.
4. All the above

Answer: (d)

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Q2. The below diagram refers to a T. S. of anther. Identify A to E respectively-

1. Sporogenous tissue, tapetum, epidermis, middle layer, endothecium
2. Sporogenous tissue, epidermis, middle layer, tapetum, endothecium
3. Sporogenous tissue, epidermis, tapetum, middle layer, endothecium
4. Sporogenous tissue, tapetum, middle layer, epidermis, endothecium

Answer: (a)

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Q3. Unisexuality of flowers prevents

1. geitonogamy, but not xenogamy
2. autogamy, but not geitonogamy
3. autogamy and geitonogamy
4. both geitonogamy and xenogamy

Answer: (b)

Unisexuality or dicliny is a condition in which two types of unisexual flowers are present i.e., staminate (male flower) and pistillate (female flower). The plant may be monoecious or dioecious. This is a device for cross pollination (or xenogamy).

Both xenogamy and geitonogamy (i.e., transfer of pollen from anther of one flower to stigma of another flower of either the same or genetically similar plant) are included under allogamy/ cross pollination. Autogamy or self pollination (i.e., transfer of pollen from anther to stigma of the same flower) occurs in bisexual flower.

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Q4. Syncarpous condition is referred to as

1. More than one pistil fused together
2. Gynoecium containing single pistil
3. More than one pistil free from one another
4. Gynoecium containing many pistils

Answer: (a)

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Q5. A close relation between flower and pollinating agent is best exhibited by :

1. Cocos
2. Yucca
3. Salvia
4. Avena

Answer: (b)

Obligate symbiotic relationship is present between Yucca flowers and moth, Tageticula.

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Q6. Double fertilization is fusion of

1. two eggs
2. one male gamete with egg and other with synergid
3. two eggs and polar nuclei with pollen nuclei
4. one male gamete with egg and other with secondary nucleus

Answer: (d)

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Q7. Megasporangia is referred to as

1. Ovary
2. Ovule
3. Gynoecium
4. All of these

Answer: (b)

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Q8. Assertion: Pollen bank can be formed for crop breeding programmes.

Reason: Pollen grain of many species can be stored for year in liquid nitrogen (–196°C).

1. If both the assertion and reason are true but the reason is not a correct explanation of the assertion.
2. If both the assertion and the reason are true and the reason is a correct explanation of the assertion.
3. If the assertion is true but the reason is false.
4. If both the assertion and reason are false.

Answer: (b)

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Q9. From among the situations given below, choose the one that prevents both autogamy and geitonogamy.

1. Monoecious plant bearing unisexual flowers.
2. Monoecious plant with bisexual flowers.
3. Dioecious plant bearing only male or female flowers.
4. Dioecious plant with bisexual flowers.

Answer: (c)

The method of self-pollination in which the transfer of pollen grains from anther to stigma of the same flower takes place is called autogamy. While geitonogamy, is the transfer of pollen grains from anther to stigma of another flower of the same plant.

In the above condition, dioecious plants, that bear only male or female flowers prevent both autogamy and geitonogamy. Geitonogamy is ecologically cross-pollination which is supposed to be equivalent to self-pollination because all flowers on a plant are genetically identical.

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Q10. What are the parts A, B, C, D and E in the below figure?

1. A: Middle layers, B: Endothecium, C: Tapetum, D: Epidermis, E: Microspore mother cell
2. A: Tapetum, B: Middle layers, C: Microspore mother cells, D: Endothecium, E: Epidermis
3. A: Endothecium, B: Epidermis, C: Tapetum, D: Endothecium, E: Microspore mother cell
4. A: Epidermis, B: Endothecium, C: Middle layers, D: Microspore mother cells, E: Tapetum

Answer: (d)

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Q11. If a diploid female plant and a tetraploid male plant are crossed, the ploidy of endosperm shall be

1. tetraploid
2. diploid
3. triploid
4. pentaploid

Answer: (a)

Diploid female plant will have 2 polar nuclei (each haploid) with which one male gamete form tetraploid male plant (male gamete of tetraploid plant will be diploid) fuses, making endosperm. So endosperm will be tetraploid.

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Q12. Albuminous seeds store their reserve food mainly in

1. perisperm
2. cotyledons
3. endosperm
4. hypocotyl

Answer: (c)

Endosperm is the nutritive tissue which provides nourishment to the embryo in seed plant. Albuminous seeds retain a part of endosperm as it is not completely used up during embryo development (e.g., wheat, maize, barley, castor, sunflower).

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Q13. Which one of the following is correct for artificial hybridization?

1. Combine desirable characters to produce superior varieties.
2. Approach towards crop improvement programme.
3. Desired pollen grains are used for pollination.
4. Stigma is exposed to receive pollen.

1. Only A
2. All are correct
3. Only A and B
4. Only A, B and C

Answer: (d)

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Q14. Male gametes in angiosperms are formed by

1. Meiotic division in pollen mother cell
2. Mitotic division in vegetative cell
3. Meiotic division in vegetative cell
4. Mitotic division in generative cell

Answer: (d)

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Q15. 60% of the angiosperms shed their pollens at the

1. 3-celled stage
2. 2-celled stage
3. 4-celled stage
4. 1-celled stage

Answer: (b)

60% of angiosperms shed their pollens at 2-celled stage and in rest 40%, the pollens are shed at 3-celled stage.

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Q16. Which one of the following statements is wrong ?

1. Vegetative cell is larger than generative cell
2. Intine is made up of cellulose and pectin
3. Pollen grains in some plants remain viable for months
4. When pollen is shed at two-celled stage, double fertilization does not take place

Answer: (d)

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Q17. In a type of apomixis known as adventive embryonic, embryos develop directly from the

1. nucellus or integuments
2. synergids or antipodals in an embryo sac
3. zygote
4. accessory embryo sacs in the ovule

Answer: (a)

Normal type of sexual reproduction having two regular features, i.e., meiosis and fertilisation, is called amphimixis. But in some plants, this normal sexual reproduction (amphimixis) is replaced by some abnormal type of sexual reproduction called apomixis.

Apomixis may be defined as, 'abnormal kind of sexual reproduction in which egg or other cells associated with egg (synergids, antipodals, etc.) develop into embryo without fertilisation and with or without meiosis'.

Adventive embryony is a type of apomixis in which development of embryos directly takes place from sporophytic tissues like nucellus and integuments, e.g., Citrus, mango, etc.

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Q18. Endosperm is completely consumed during seed formation in

1. Castor and coconut
2. Pea, castor and coconut
3. Pea and beans
4. Groundnut and castor

Answer: (c)

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Q19. Flowers are considered as objects of

1. Ornamental value
2. Aesthetic value
3. Religious and cultural value
4. All of these

Answer: (d)

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Q20. The microsporangium cells which possess dense cytoplasm and have more than one nucleus is the characteristic of

1. Tapetum
2. Middle layers
3. Endothecium
4. Epidermis

Answer: (a)

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Q21. Pollination in plants is referred to as

1. Transfer of pollen grain to stigma of pistil.
2. Fusion of male and female gametes.
3. Germination of pollen of stigma.
4. Production of pollen grew inside the microsporangium.

Answer: (a)

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Q22. Which type of association is found in between entomophilous flower and pollinating agent?

1. Mutualism
2. Cooperation
3. Commensalism
4. Co-evolution

Answer: (a)

Commensalism is an interaction between two individuals in which one is benefitted while the other is unaffected. In mutualism both individuals are beneficial for each other. The pollinating insect gets nectar from flower and in turn helps in pollination of flowers.

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Q23. The devices developed by plants to discourage self-pollination include

1. In some species, the pollen release and receptive stigma are not synchronized.
2. In some species, the anther and stigma are placed at different positions, so they do not come in contact.
3. Self-incompatibility

1. A and B only
2. All are correct
3. A only
4. B only

Answer: (b)

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Q24. Double fertilization and triple fusion were discovered by

1. Hofmeister
2. Leeuwenhoek
3. Nawaschin and Guignard
4. Strasburger

Answer: (c)

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Q25. When an ovary develops into a fruit, without fertilization, it is called

1. apospory
2. parthenocarpy
3. apogamy
4. porogamy

Answer: (b)

Parthenocarpy is the development of a fruit without the formation of seeds as a result of lack of pollination, lack of fertilization and lack of development. This condition can be artificially induced by application of hormones.

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Q26. Syngamy means

1. fusion of gametes
2. fusion of two similar spores
3. fusion of cytoplasms
4. fusion of two dissimilar spores

Answer: (a)

Syngamy means fusion of gametes. Syngamy is the phenomenon in which male gamete fuses with an egg.

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Q27. What are A and B in the following figure?

1. A: Vacuoles, B: Nucleus
2. A: Vacuoles, B: Intine
3. A: Nucleus, B: Intine
4. A: Exine, B: Intine

Answer: (a)

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Q28. Assertion : Endosperm is a nutritive tissue and it is triploid.

Reason: Endosperm is formed by fusion of secondary nucleus to second male gamete. It is used by developing embryo.

1. If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion.
2. If Assertion is true but Reason is false.
3. If both Assertion and Reason are true but the Reason is not the correct explanation of the Assertion.
4. If both Assertion and Reason are false.

Answer: (a)

Male gamete (n) + secondary nucleus (2n) = primary endosperm nucleus which develops into endosperm (3n) Endosperem is the reserve food used by developing embryo.

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Q29. Find out the correct statement(s).

1. Most common endosperm is of nuclear type.
2. Coconut water is male gametophyte.
3. Coconut has both free-nuclear and cellular type of endosperm.

1. I and III
2. I, II and III
3. II and III
4. I and II

Answer: (a)

Statements I and III are correct, but statement II is incorrect and can be corrected as The coconut water from tender coconut represents free-nuclear endosperm not male gametophyte and the surrounding white kernel is the cellular endosperm.

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Q30. Water is the main medium of transport for male gametes of

1. Bryophytes
2. Algae
3. Pteridophyte
4. All of these

Answer: (d)

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Q31. Megasporangium is equivalent to

1. nucellus
2. embryo sac
3. ovule
4. fruit.

Answer: (a)

In angiosperms, body of the ovule consists of a mass of parenchymatous cells called nucellus, which is equivalent to megasporangium. A megasporangium along with its protective integuments is called as an ovule.

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Q32. Post-fertilization events do not include

1. Formation of primary endosperm cell
2. Maturation of ovules in seed
3. Formation of ovary into fruit
4. Formation of embryo inside seed

1. Only B
2. Only A
3. Only C
4. None of these

Answer: (b)

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Q33. An interesting modification of flower shape for insect pollination occurs in some orchids in which a male insect mistakes the pattern on the orchid flower for the female species and tries to copulate with it, thereby pollinating the flower. This phenomenon is called

1. pseudopollination
2. mimicry
3. pseudoparthenocarpy
4. pseudocopulation.

Answer: (d)

In an orchid Ophrys speculum, there is most interesting and unique mechanism of pollination. Here pollination occurs by a wasp called Culpa aurea. In this orchid, pollination occurs by act of pseudocopulation.

The appearance and odour of Ophrys is similar to female wasp and are mistake by male wasps and they land on Ophrys flowers to perform act of pseudo- copulation and thus pollination takes place. This plant-insect relationship is useful only to plant.

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Q34. Ovule is straight with funiculus, embryo sac, chalaza and micropyle lying on one straight line. It is

1. orthotropous
2. campylotropous
3. anatropous
4. amphitropous

Answer: (a)

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Q35. Pollination in water hyacinth and water lily is brought about by the agency of

1. Birds
2. Insects or wind
3. Bats
4. Water

Answer: (b)

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Q36. Flowers convey important human feelings such as

1. Happiness and grief
2. Love and aff ection
3. Mourning
4. All of these

Answer: (d)

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Q37. Unisexuality of flowers prevents

1. geitonogamy, but not xenogamy
2. autogamy, but not geitonogamy
3. autogamy and geitonogamy
4. both geitonogamy and xenogamy.

Answer: (b)

Unisexuality or dicliny is a condition in which two types of unisexual flowers are present i.e., staminate (male flower) and pistillate (female flower). The plant may be monoecious or dioecious. This is a device for cross pollination (or xenogamy).

Both xenogamy and geitonogamy (i.e. transfer of pollen from anther of one flower to stigma of another flower of either the same or genetically similar plant) are included under allogamy/cross pollination. Autogamy or self pollination (i.e. transfer of pollen from anther to stigma of the same flower) occurs in bisexual flower.

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Q38. The reward produced by plants to their animal visitors is in the form of

1. Pollen grain
2. Nectar
3. Both (a) and (b)
4. None of these

Answer: (c)

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Q39. Persistent nucellus in the seed is known as

1. tegmen
2. perisperm
3. chalaza
4. hilum

Answer: (b)

In some seeds, remains of nucellus persist. This residual nucellus which persists in the seed is called perisperm, e.g., black pepper, coffee, castor, cardamum, Nymphaea.

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Q40. From among the sets of terms given below, identify those that are associated with the gynoecium.

1. Thalamus, pistil, style, ovule
2. Stigma, ovule, embryo sac, placenta
3. Ovule, ovary, embryo sac, tapetum
4. Ovule, stamen, ovary, embryo sac

Answer: (b)

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Q41. Which of the following are the important floral rewards to the animal pollinators?

1. Nectar and pollen grains
2. Protein pellicle and stigmatic exudates
3. Floral fragrance and calcium crystals
4. Colour and large size flower

Answer: (a)

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Q42. Identify the parts labelled as A to D in structure of seed given below.

1. A– Plumule, B– Coleoptile, C– Coleorhiza, D– Radicle
2. A– Coleoptile, B– Plumule, C– Radicle, D– Coleorhiza
3. A– Coleorhiza, B– Radicle, C– Plumule, D– Coleoptile
4. A– Radicle, B– Plumule, C– Coleoptile, D– Coleorhiza

Answer: (b)

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Q43. Embryo sac represents

1. megaspore
2. megasporophyll
3. megagametophyte
4. megagamete

Answer: (c)

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Q44. Which one of the following is resistant to enzyme action?

1. Cork
2. Pollen exine
3. Wood fibre
4. Leaf cuticle

Answer: (b)

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Q45. How many nuclei are found in female gametophyte?

1. 7
2. 8
3. 6
4. 5

Answer: (b)

A typical angiospermic embryo sac at maturity has 8-nuclei. Six out of the eight nuclei are surrounded by cell walls and organised into cells (egg apparatus and antipodal cells) and the remaining two nuclei, called polar nuclei, are situated below the egg apparatus in the large central cell.

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Q46. Which of the following is correct for the relationship existence between moth and yucca plant?

1. Moth deposits egg in the locule of the ovary and the flower and in turn flower gets pollinated by the moth.
2. Moth and the plant cannot complete their life cycle without each other.
3. Larva of the moth comes out of the eggs as the seeds start developing.
4. All the above

Answer: (d)

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Q47. Assertion: Pollen grains are well preserved as fossils.

Reason: Pollen posses sporopollenin.

1. If both the assertion and reason are true but the reason is not a correct explanation of the assertion.
2. If both the assertion and the reason are true and the reason is a correct explanation of the assertion.
3. If the assertion is true but the reason is false.
4. If both the assertion and reason are false.

Answer: (b)

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Q48. Out of the following choose the post-fertilisation event(s).

1. Embryogenesis
2. Endospermogenesis
3. Both (a) and (b)
4. Megasporogenesis

Answer: (c)

Endospermogenesis and embryogenesis are the post-fertilisation event under which formation of endosperm and embryo take place. Whereas, megasporogenesis is the formation of megaspores and is a pre-fertilisation event.

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Q49. Which one of the following statement is incorrect?

1. When pollen is shed at two-celled stage, double fertilization does not take place.
2. Pollen grains in some plants remain viable for months.
3. Vegetative cell is larger than generative cell.
4. Intine is made up of cellulose and pectin.

Answer: (a)

In over 60 per cent of angiosperms, pollen grains are shed at cell 2-celled stage. In the remaining species the generative cell divides mitotically to give rise to the two male gametes before pollen grains are shed (3-celled stage.)

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Q50. In majority of angiosperms

1. Reduction division occurs in the megaspore mother cells
2. There are numerous antipodal cells
3. A small central cell is present in the embryo sac
4. Egg has a filiform apparatus

Answer: (a)

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Q51. Assertion: The ploidy of primary endosperm nucleus (PEN) in angiosperm is 3n.

Reason: PEN is formed by triple fusion.

1. If both the assertion and reason are true but the reason is not a correct explanation of the assertion.
2. If both the assertion and the reason are true and the reason is a correct explanation of the assertion.
3. If the assertion is true but the reason is false.
4. If both the assertion and reason are false.

Answer: (b)

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Q52. Wind pollinated and water pollinated flowers

1. are non-colourful
2. are colourful
3. are small in size
4. produce nectar

Answer: (a)

Wind pollinated and water pollinated flowers are non-colourful. As these do not need any biotic agency for pollination, there is no need for fragrance, nectar and colourfulness.

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Q53. Which one of the following statements regarding post-fertilisation development in flowering plants is incorrect?

1. Ovules develop into embryo sac.
2. Zygote develops into embryo.
3. Ovary develops into fruit.
4. Central cell develops into endosperm

Answer: (a)

Ovules develop into seeds.

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Q54. In the embryos of a typical dicot and a grass, true homologous structures are

1. coleoptile and scutellum
2. coleorhiza and coleoptile
3. cotyledons and scutellum
4. hypocotyl and radicle

Answer: (c)

In the embryos of a typical dicot and a grass (monocot), true homologous structures are cotyledons and scutellum. This is because in the monocots such as the grass family a single cotyledon is present which is called scutellum.

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Q55. Anemophily type of pollination is found in

1. Salvia
2. Vallisneria
3. bottlebrush
4. coconut

Answer: (d)

Anemophily is the pollination by wind. Anemophilous plants are characterised by small flowers, pollens present in large number which are small, dry and light in weight, number of ovules generally reduced in ovary, feathery or brushy stigma to receive the pollen. All these features are shown by coconut flower.

In Vallisneria, pollination occurs outside water called epihydrophily. Callistemon (Bottlebrush) is pollinated by birds and is an example of ornithophily. Salvia is insect pollinated and is an example of entomophily.

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Q56. In a cereal grain the single cotyledon of embryo is represented by

1. coleoptile
2. scutellum
3. coleorhiza
4. prophyll.

Answer: (b)

The cotyledons are known as seed leaves, they are attached to the embryonic axis. Dicotyledons typically have two cotyledons and monocotyledons have only one cotyledon. The single shield shaped cotyledon in grains is known as scutellum.

The scutellum does not contain food and its function is to absorb food from the endosperm and transfer it to the growing parts of the embryo. The plumule consists of growing tip of the shoot along with few young leaf primordia. It is covered by a sheath called coleoptile. The radicle which lies at the base of the grain is also covered with a sheath called coleorhiza. The hypocotyl is very short and is represented by a short axis in between radicle and plumule. pericarp and seed coat fused endosperm aleurone layer coleoptile leaf plumule cotyledon (scutellum) redicle coleorhiza L. S. of corn grain

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Q57. In an embryo sac, the cells that degenerate after fertilisation are:

1. synergids and primary endosperm cell
2. antipodals and primary endosperm cell
3. synergids and antipodals
4. egg and antipodals

Answer: (c)

In unfertilised embryo sac, the antipodals and synergids are present at chalazal end distinctly and micropylar end respectively. While, in a fertilised embryo sac antipodals and synergids gradually degenerate after the formation of zygote.

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Q58. The function of filiform apparatus is to

1. Stimulate division of generative cell
2. Recognize the suitable pollen at stigma
3. Produce nectar
4. Guide the entry of pollen tube

Answer: (d)

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Q59. Parthenogenesis is

1. development of embryo without fertilization
2. development of fruit without hormones
3. development of fruit without fertilization
4. development of embryo from egg without fertilization.

Answer: (d)

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Q60. Why bagging is done in an emasculated flower?

1. To pollinate the stigma with required anthers only.
2. To prevent contamination of its stigma with unwanted pollen.
3. Both (a) and (b)
4. None of these

Answer: (c)

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Q61. The phenomenon wherein, the ovary develops into a fruit without fertilisation is called

1. apomixis
2. parthenocarpy
3. asexual reproduction
4. sexual reproduction

Answer: (b)

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Q62. The viability of seeds is tested by

1. Safranine
2. 2, 3, 5 triphenyl tetrazolium chloride
3. 2, 6 dichlorophenol indophenols
4. DMSO

Answer: (b)

Dehydrogenase enzymes present in living tissue reduce the tetrazolium chloride to formazan, a reddish, water insoluble compound. This reaction occurs in or near living cells which are releasing hydrogen in respiration processes. Viable tissues produce a normal red colour, weak living tissue produce an abnormal colour. Dead tissues do not stain, remaining usually white.

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Q63. Male gametes in angiosperms are formed by the division of

1. microspore
2. vegetative cell
3. generative cell
4. microspore mother cell

Answer: (c)

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Q64. During pollen pistil the interaction chemical components are released from

1. Only pistil
2. Only pollen
3. Both pollen and pistil
4. The ovary

Answer: (c)

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Q65. The study of formation, growth and development of new individual from an egg is called

1. embryology
2. morphogenesis
3. embryogenesis
4. embryolysis

Answer: (a)

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Q66. How many embryo sacs are present in an ovule?

1. More than one embryo sac
2. One embryo sac
3. One embryo sac (generally)
4. Two embryo sacs

Answer: (c)

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Q67. The viability of seeds is tested by

1. Safranine
2. 2, 3, 5 triphenyl tetrazolium chloride
3. 2, 6 dichlorophenol indophenols
4. DMSO

Answer: (b)

Dehydrogenase enzymes present in living tissue reduce the tetrazolium chloride to formazan, a reddish, water insoluble compound. This reaction occurs in or near living cells which are releasing hydrogen in respiration processes. Viable tissues produce a normal red-colour, weak living tissue produce an abnormal colour. Dead tissues do not stain, remaining usually white.

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Q68. What is common between vegetative reproduction and apomixis?

1. Both are applicable to only dicot plants
2. Both occur round the year
3. Both bypass the flowering phase
4. Both produce progeny identical to the parent

Answer: (d)

Apomixis is a reproductive process in plants that superficially resembles normal sexual reproduction but in which there is no fusion of gametes. The embryos develop simply by division of a diploid cell the ovule.

So, the progenies produced are identical to the parent. In vegetative reproduction also progenies produced are identical to the parent.

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Q69. Functional megaspore in an angiosperm develops into an

1. endosperm
2. embryo
3. embryo sac
4. ovule

Answer: (c)

In angiosperms, the functional megaspore is the first cell of female gametophyte. It enlarges and undergoes three nuclear mitotic divisions to form embryo sac.

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Q70. In an angiosperm, how many microspore mother cells are required to produce 100 pollen grains?

1. 75
2. 25
3. 100
4. 50

Answer: (b)

Pollen grains or microspores are formed inside anther, which is the fertile portion of stamen or microsporophyll. The formation of microspores or pollens is called microsporogenesis. The primary sporogenous cell gives rise to microspore mother cells or pollen mother cells.

Each microspore mother cell on reduction division gives rise to 4 microspores or pollens. So, for the formation of 100 pollen grains, 25 MMC are required. It involves karyokinesis followed by cytokinesis.

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Q71. What is 'G' in the given figure?

1. Coleorhiza
2. Scutellum
3. Coleoptile
4. Shoot apex

Answer: (a)

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Q72. Chief pollinators of agricultural crops are

1. butterflies
2. moths
3. bees
4. beetles

Answer: (c)

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Q73. Find out A, B and C in the flowchart given below.

1. A−Endosperm, B–Female gamete, C–Male gamete
2. A–Female gamete, B–Male gamete, C–Endosperm
3. A–Male gamete, B–Polar nuclei, C–Endosperm
4. A–Female gamete, B–Endosperm, C–Male gamete

Answer: (c)

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Q74. Identify the parts of A to F in the following figure?

1. A: Antipodals, B: Polar nuclei, C: Central cell, D: Egg, E: Synergids, F: Filiform apparatus
2. A: Filiform apparatus, B: Polar nuclei, C: Antipodals, D: Synergids, E: Egg, F: Central cell
3. A: Antipodals, B: Central cell, C: Polar nuclei, D: Egg, F: Synergids, G: Filiform apparatus
4. A: Eggs, B: Central cell, C: Filiform apparatus, D: Polar nuclei, E: Antipodals, F: Synergids

Answer: (a)

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Q75. Wind pollinated flowers are

1. Small, producing large number of dry pollen grains
2. Small, brightly coloured, producing large number of pollen grains
3. Large, producing abundant nectar and pollen
4. Small, producing nectar and dry pollen

Answer: (a)

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Q76. Which one of the following statements is wrong?

1. When pollen is shed at two-celled stage, double fertilisation does not take place.
2. Pollen grains in some plants remain viable for months.
3. Vegetative cell is larger than generative cell.
4. Intine is made up of cellulose and pectin

Answer: (a)

In 60% of flowering plants, the pollen grains are shed at two-celled stage (tube cell + generative cell). Further, development of male gametophyte (pollen grain) occurs on stigma. Pollen grain gives rise to pollen tube which absorbs nourishment from the cells of style for its growth.

Generative cell divides to give rise to two male gametes. Out of these, one fuses with the egg to form diploid zygote (generative fertilisation or syngamy) whereas the second male gamete fuses with the two haploid polar nuclei or diploid secondary nucleus of the central cell to form primary endosperm nucleus (vegetative fertilisation or triple fusion). These two acts of fertilisation occur in the same embryo sac and are referred to as double fertilisation.

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Q77. The arrangement of the nuclei in a normal embryo sac in the dicot plants is

1. 3 + 3 + 2
2. 3 + 2 + 3
3. 2 + 4 + 2
4. 2 + 3 + 3.

Answer: (b)

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Q78. Which one of the following pairs of plant structures has haploid number of chromosomes?

1. Megaspore mother cell and antipodal cells
2. Nucellus and antipodal cells
3. Egg cell and antipodal cells
4. Egg nucleus and secondary nucleus

Answer: (c)

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Q79. Assertion: Embryos of monocotyledons posses only one cotyledon.

Reason: In the grass family the cotyledon is called scutellum.

1. If both the assertion and reason are true but the reason is not a correct explanation of the assertion.
2. If both the assertion and the reason are true and the reason is a correct explanation of the assertion.
3. If the assertion is true but the reason is false.
4. If both the assertion and reason are false.

Answer: (a)

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Q80. Whorl of carpel in flower represents

1. Androecium
2. Gynoecium
3. Calyx
4. Corolla

Answer: (b)

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Q81. What is common between vegetative reproduction and apomixis?

1. Both are applicable to only dicot plants.
2. Both occur round the year.
3. Both bypass the flowering phase.
4. Both produce progeny identical to the parent

Answer: (d)

Apomixis is a reproductive process in plants that superficially resembles normal sexual reproduction but in which there is no fusion of gametes. The embryos develop simply by division of a diploid cell the ovule.

So, the progenies produced are identical to the parent. In vegetative reproduction, the progenies produced are also identical to the parent.

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Q82. In a flower, if the megaspore mother cell forms megaspores without undergoing meiosis and if one of the megaspores develops into an embryo sac, its nuclei would be

1. diploid
2. haploid
3. a few haploid and a few diploid
4. with varying ploidy

Answer: (a)

Megaspore mother cell is diploid (2n). lf it forms megaspores without meiosis, the megaspores will be diploid (2n) too. If this diploid megaspore develops into embryo sac, its nuclei would also be diploid.

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Q83. Entry of pollen tube through micropyle is

1. chalazogamy
2. porogamy
3. mesogamy
4. pseudogamy

Answer: (b)

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Q84. Formation of diploid embryo sac from diploid vegetative structure is called

1. diplospory
2. adventive polyembryony
3. apospory
4. apomixis

Answer: (c)

When a diploid vegetative cell (nucellus cell) gives rise to diploid embryo sac directly, it is called apospory.

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Q85. Wheat is the ploidy of perisperm

1. 2n
2. n
3. 3n
4. 4n

Answer: (a)

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Q86. Match the following columns.

Codes A B C D E

1. 1 2 3 4 5
2. 5 4 3 2 1
3. 1 3 2 4 5
4. 5 4 1 2 3

Answer: (b)

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Q87. Pollen grains can be stored for several years in liquid nitrogen having temperature of

1. – 80°C
2. – 196°C
3. – 120°C
4. – 160°C

Answer: (b)

Pollen grains can be stored for several years in liquid nitrogen having a temperature of −196°C (cryopreservation). Pollen grains can be later used in plant breeding programmes.

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Q88. Landing platform for pollen grains is

1. Style
2. Stigma
3. Ovary
4. None of them

Answer: (b)

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Q89. The cells located at chalazal ends are called as

1. Antipodals
2. Synergids
3. Egg apparatus
4. None of these

Answer: (a)

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Q90. Endosperm is formed during the double fertilization by

1. two polar nuclei and one male gamete
2. ovum and male gamete
3. one polar nuclei and one male gamete
4. two polar nuclei and two male gametes.

Answer: (a)

Double fertilization is the simultaneous occurrence of syngamy and triple fusion. Syngamy involves fusion of one male gamete with egg cell to form zygote. The result of syngamy is zygote (2n) which ultimately develops into embryo.

The second male gamete fuses with 2 polar nuclei or secondary nucleus to form triploid primary endosperm nucleus and this is called triple fusion. This primary endosperm nucleus (3n) ultimately develops into a nutritive tissue for developing embryo called endosperm.

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Q91. What does the filiform apparatus do at the entrance into ovule?

1. It helps in the entry of pollen tube into a synergid.
2. It brings about opening of the pollen tube.
3. It prevents entry of more than one pollen tube into the embryo sac.
4. It guides pollen tube from a synergid to egg.

Answer: (a)

Fili form apparatus helps in the entry of pollen tube into a synergid in ovule. Filiform apparatus is in form of finger like projection comprising a core of microfibrils enclosed in a sheath. The filiform apparatus resembles transfer cells meant for short-distance movement of metabolites. The filiform apparatus is responsible for the absorption of food from the nucleus.

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Q92. What does the filiform apparatus do at the entrance into ovule?

1. It brings about opening of the pollen tube.
2. It helps in the entry of pollen tube into a synergid.
3. It guides pollen tube from a synergid to egg.
4. It prevents entry of more than one pollen tube into the embryo sac

Answer: (c)

Within the embryo sac three cells are grouped together at the micropylar end and constitute the egg apparatus. The egg apparatus, in turn, consists of two synergids and one egg cell. The synergids have special cellular thickenings at the micropylar tip called filiform apparatus, which plays an important role in guiding the pollen tubes from synergid to egg. Three cells are at the chalazal end and are called the antipodals. The large central cell, has two polar nuclei.

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Q93. Light and non-sticky pollen grains are favourable for

1. Wind pollinated plant
2. Water pollinated plant
3. Plants with fatherly sigma
4. Both (b) and (c)

Answer: (a)

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Q94. Which is most crucial for seed storage?

1. Endosperm and water
2. Dehydration and dormancy
3. Least amount of development
4. Endosperm in large quantity

Answer: (b)

Dehydration and dormancy are most crucial for seed storage. In dehydration, there is less amount of water due to which the seed enzymes cannot work and hence, there will be no germination. Dormancy is the time period in which seed cannot grow due to inactive state of embryo or lacking of other necessary condition for growing.

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Q95. Adventive embryonic in Citrus is due to

1. nucellus
2. zygotic embryo
3. integuments
4. fertilized egg

Answer: (a)

Presence of more than one embryo inside the seed is called polyembryony. It is more common in gymnosperms than angiosperms. In angiosperms, it is generally present as an unusual feature in few cases like Citrus, mango, etc.

In Citrus many embryos are formed from the structures outside the embryo (like nucellus). This is commonly called adventive polyembryony. In Citrus upto 10 nucellar embryos are formed.

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Q96. In an embryo sac, the cells that degenerate after fertilization are

1. Synergid and antipodal
2. Synergid and primary endosperm nucleus cell
3. Antipodal and primary endosperm nucleus cell
4. Egg and antipodals

Answer: (a)

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Q97. Identify the A to E in the following diagram of typical dicot embryo.

1. A–Radicle, B–Root cap, C–Plumule, D–Hypocotyl, E–Cotyledons
2. A–Cotyledons, B–Hypocotyl, C–Plumule, D–Root cap, E–Radicle
3. A–Hypocotyl, B–Cotyledons, C–Plumule, D–Radicle, E–Root cap
4. A–Plumule, B–Cotyledons, C–Hypocotyl, D–Radicle, E–Root cap

Answer: (d)

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Q98. A Polygonum type of embryo sac is

1. 7-celled and 8-nucleate
2. 7-celled and 7-nucleate
3. 8-celled and 7-nucleate
4. 8-celled and 8-nucleate

Answer: (a)

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Q99. Which one of the following statements is not true?

1. Pollen grains of many species cause severe allergies.
2. Tapetum helps in the dehiscence of anther.
3. Stored pollen in liquid nitrogen can be used in the crop breeding programmes.
4. Exine of pollen grains is made up of sporopollenin.

Answer: (b)

Tapetum is the innermost wall layer of microsporangium that nourishes developing pollen grains.

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Q100. Occurrence of more than one embryo is called

1. embryony
2. polyembryony
3. parthenogenesis
4. fertilisation

Answer: (b)

Occurrence of more than one embryo is called polyembryony. It is generally observed in Citrus varieties. Orange and lemon are common examples of polyembryony.

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