MCQs on Sexual Reproduction in Flowering Plants – CBSE Class 12 Biology

Course: CBSE Class 12 Biology | Unit I: Reproduction
NCERT-Based MCQs with Answers and Concept-Clearing Explanations

Section A: Introduction to Sexual Reproduction in Flowering Plants

Q1. Sexual reproduction in flowering plants involves the formation of

A. spores only
B. seeds without fertilisation
C. male and female gametes
D. vegetative buds

Correct Answer: C
Explanation: Sexual reproduction requires the formation of male (pollen grains) and female (egg) gametes, followed by fertilisation.

Q2. The reproductive unit of angiosperms is the

A. seed
B. fruit
C. flower
D. ovule

Correct Answer: C
Explanation: The flower contains both male and female reproductive organs, making it the reproductive unit.

Q3. Flowers that possess both androecium and gynoecium are called

A. unisexual
B. bisexual
C. neuter
D. sterile

Correct Answer: B
Explanation: Bisexual flowers have both male and female reproductive structures.

Section B: Structure of Flower and Reproductive Parts

Q4. The male reproductive organ of a flower is the

A. pistil
B. carpel
C. stamen
D. ovary

Correct Answer: C
Explanation: Stamen consists of anther and filament and produces pollen grains.

Q5. The female reproductive part of a flower is known as

A. anther
B. filament
C. gynoecium
D. thalamus

Correct Answer: C
Explanation: Gynoecium includes stigma, style, and ovary.

Q6. Pollen grains are produced in the

A. filament
B. ovary
C. anther
D. stigma

Correct Answer: C
Explanation: Anthers contain pollen sacs (microsporangia) where pollen grains develop.

Q7. The receptive surface for pollen grains is the

A. ovule
B. stigma
C. style
D. ovary

Correct Answer: B
Explanation: The stigma receives pollen during pollination.

Section C: Microsporogenesis and Pollen Grain

Q8. Microsporogenesis refers to

A. formation of ovules
B. formation of pollen grains
C. fertilisation
D. seed formation

Correct Answer: B
Explanation: It is the process by which microspore mother cells form pollen grains through meiosis.

Q9. Each microspore mother cell produces how many microspores?

A. One
B. Two
C. Three
D. Four

Correct Answer: D
Explanation: Meiosis produces four haploid microspores.

Q10. The outer wall of a pollen grain is made of

A. cellulose
B. pectin
C. sporopollenin
D. lignin

Correct Answer: C
Explanation: Sporopollenin is highly resistant and protects pollen grains.

Q11. How many cells are present in a mature pollen grain at shedding stage?

A. One
B. Two
C. Three
D. Four

Correct Answer: B
Explanation: A mature pollen grain contains a vegetative cell and a generative cell.

Section D: Megasporogenesis and Embryo Sac

Q12. Megasporogenesis occurs in the

A. anther
B. ovary
C. ovule
D. stigma

Correct Answer: C
Explanation: Megaspore mother cell in the ovule undergoes meiosis.

Q13. How many functional megaspores remain after megasporogenesis?

A. Four
B. Three
C. Two
D. One

Correct Answer: D
Explanation: Only one megaspore remains functional; others degenerate.

Q14. The most common type of embryo sac in angiosperms is

A. monosporic
B. bisporic
C. tetrasporic
D. polysporic

Correct Answer: A
Explanation: The Polygonum type embryo sac is monosporic.

Q15. A mature embryo sac contains

A. 5 cells, 6 nuclei
B. 6 cells, 7 nuclei
C. 7 cells, 8 nuclei
D. 8 cells, 8 nuclei

Correct Answer: C
Explanation: Typical embryo sac has 7 cells and 8 nuclei.

Section E: Pollination

Q16. Transfer of pollen grains from anther to stigma is called

A. fertilisation
B. pollination
C. germination
D. dispersal

Correct Answer: B
Explanation: Pollination precedes fertilisation.

Q17. Pollination within the same flower is known as

A. geitonogamy
B. xenogamy
C. autogamy
D. hybridisation

Correct Answer: C
Explanation: Autogamy occurs within the same flower.

Q18. Which type of pollination promotes genetic variation?

A. Autogamy
B. Geitonogamy
C. Xenogamy
D. Cleistogamy

Correct Answer: C
Explanation: Xenogamy involves different plants, increasing variation.

Q19. Wind-pollinated flowers generally have

A. sticky pollen
B. large petals
C. light and dry pollen
D. nectar

Correct Answer: C
Explanation: Light pollen is easily carried by wind.

Q20. Which agent is most commonly involved in pollination?

A. Water
B. Wind
C. Insects
D. Birds

Correct Answer: C
Explanation: Entomophily (insect pollination) is the most common.

Section F: Fertilisation and Double Fertilisation

Q21. Entry of pollen tube into ovule usually occurs through

A. chalaza
B. funiculus
C. micropyle
D. integument

Correct Answer: C
Explanation: Most angiosperms show porogamy.

Q22. Fusion of one male gamete with egg is called

A. triple fusion
B. syngamy
C. pollination
D. fusion

Correct Answer: B
Explanation: Syngamy forms the zygote.

Q23. Triple fusion results in formation of

A. zygote
B. embryo
C. endosperm
D. seed coat

Correct Answer: C
Explanation: Male gamete fuses with two polar nuclei forming primary endosperm nucleus.

Q24. Double fertilisation is unique to

A. algae
B. bryophytes
C. gymnosperms
D. angiosperms

Correct Answer: D
Explanation: Double fertilisation is a characteristic feature of flowering plants.

Q25. Endosperm is generally

A. haploid
B. diploid
C. triploid
D. tetraploid

Correct Answer: C
Explanation: It is formed by fusion of one male gamete and two polar nuclei.

Section G: Post-Fertilisation Changes

Q26. Ovule after fertilisation develops into

A. fruit
B. seed
C. embryo
D. endosperm

Correct Answer: B
Explanation: Ovule transforms into seed.

Q27. Ovary develops into

A. seed
B. embryo
C. fruit
D. endosperm

Correct Answer: C
Explanation: Ovary wall forms pericarp of fruit.

Q28. The part of seed that stores food is

A. plumule
B. radicle
C. cotyledon
D. testa

Correct Answer: C
Explanation: Cotyledons store reserve food.

Q29. Seed coat develops from

A. ovary wall
B. integuments
C. nucellus
D. embryo sac

Correct Answer: B
Explanation: Integuments form the protective seed coat.

Q30. Which tissue nourishes the developing embryo?

A. Perisperm
B. Endosperm
C. Integument
D. Testa

Correct Answer: B
Explanation: Endosperm provides nutrition.

Section H: Apomixis and Polyembryony

Q31. Formation of seeds without fertilisation is called

A. parthenocarpy
B. apomixis
C. polyembryony
D. hybridisation

Correct Answer: B
Explanation: Apomixis bypasses meiosis and fertilisation.

Q32. Advantage of apomixis in agriculture is

A. genetic variation
B. seedlessness
C. fixation of hybrid traits
D. slow reproduction

Correct Answer: C
Explanation: Desired traits are preserved across generations.

Q33. Presence of more than one embryo in a seed is called

A. apomixis
B. parthenocarpy
C. polyembryony
D. fertilisation

Correct Answer: C
Explanation: Multiple embryos may develop from different structures.

Q34. Polyembryony is commonly seen in

A. wheat
B. rice
C. citrus
D. mustard

Correct Answer: C
Explanation: Citrus shows nucellar polyembryony.

Section I: Conceptual and Application-Based MCQs

Q35. Which structure prevents self-pollination?

A. Bisexuality
B. Cleistogamy
C. Dichogamy
D. Autogamy

Correct Answer: C
Explanation: Dichogamy ensures anther and stigma mature at different times.

Q36. Pollen viability is highest in

A. wheat
B. rice
C. pea
D. legumes like pea

Correct Answer: D
Explanation: Some pollen grains remain viable for months.

Q37. Which cell of embryo sac attracts pollen tube?

A. Egg
B. Synergid
C. Antipodal
D. Polar nuclei

Correct Answer: B
Explanation: Synergids have filiform apparatus guiding pollen tube.

Q38. The edible part of coconut is

A. perisperm
B. embryo
C. endosperm
D. nucellus

Correct Answer: C
Explanation: Coconut water and kernel are endosperm.

Q39. Which event ensures triploid endosperm formation?

A. Syngamy
B. Meiosis
C. Triple fusion
D. Pollination

Correct Answer: C
Explanation: Triple fusion forms triploid endosperm.

Q40. Which structure forms the seed stalk?

A. Hilum
B. Funiculus
C. Micropyle
D. Chalaza

Correct Answer: B
Explanation: Funiculus attaches seed to fruit wall.

Section J: Higher-Order Thinking MCQs

Q41. Why is double fertilisation considered advantageous?

A. Produces more embryos
B. Saves energy
C. Endosperm forms only after fertilisation
D. Prevents mutation

Correct Answer: C
Explanation: Ensures resource allocation only to fertilised ovules.

Q42. Which process ensures cross-pollination genetically?

A. Autogamy
B. Cleistogamy
C. Xenogamy
D. Geitonogamy

Correct Answer: C
Explanation: Xenogamy involves different plants.

Q43. Which part of pollen grain forms pollen tube?

A. Exine
B. Intine
C. Sporopollenin
D. Germ pore

Correct Answer: B
Explanation: Intine grows out to form pollen tube.

Q44. The nutritive tissue present before fertilisation is

A. endosperm
B. perisperm
C. nucellus
D. cotyledon

Correct Answer: C
Explanation: Nucellus provides nutrition before fertilisation.

Q45. Which condition favours self-pollination?

A. Dichogamy
B. Herkogamy
C. Cleistogamy
D. Xenogamy

Correct Answer: C
Explanation: Cleistogamous flowers never open.

Q46. In angiosperms, fertilisation occurs in the

A. ovary
B. ovule
C. stigma
D. style

Correct Answer: B
Explanation: Fertilisation takes place inside the ovule.

Q47. Which cell degenerates after fertilisation?

A. Egg
B. Synergids
C. Zygote
D. Endosperm

Correct Answer: B
Explanation: Synergids degenerate after pollen tube entry.

Q48. Why is sporopollenin important?

A. Nutrition
B. Germination
C. Protection
D. Fertilisation

Correct Answer: C
Explanation: It protects pollen grains from harsh conditions.

Q49. Which structure indicates point of pollen tube entry?

A. Chalaza
B. Funiculus
C. Hilum
D. Micropyle

Correct Answer: D
Explanation: Micropyle allows pollen tube entry.

Q50. The ultimate product of sexual reproduction in flowering plants is

A. embryo
B. endosperm
C. seed
D. fruit

Correct Answer: C
Explanation: Seed ensures continuity of plant life.

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