Biology class 12th
Chapter Wise Important Questions
CBSE Board 2024
Sexual Reproduction in Flowering Plants
1 Marks MCQs
1. The two nuclei at the end of the pollen tube are called:
a. Generative nucleus and stigma
b. Tube nucleus and sperm
c. Tube nucleus and a generative nucleus
d. Sperm and ovum
2. The embryo sac is located inside the
a. Micropyle
b. Stigma
c. Ovule
d. Style
3. Functional megaspore in a flowering plant develops into
a. Endosperm
b. Embryo
c. Ovule
d. Embryo-sac
4. The process of formation of seeds without fertilization in flowering plants is known as
a. Budding
b. Sporulation
c. Somatic hybridization
d. Apomixis
5. A dioecious flowering plant prevents.
a. Geitonogamy and xenogamy
b. Autogamy and geitonogamy
c. Cleistogamy and xenogamy
d. Autogamy and xenogamy
Assertion & Reason
1. Assertion: Pollen grains from a male parent are mostly transferred to the stigma in the
female parent by some external agency.
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Reason: This is because the male flowers or male organs have no internal device to reach the
female organs in another flower.
2. Assertion: An angiospermous flower represents the modified condensed shoot that performs
the function of sexual reproduction.
Reason: The fertile leaves of the shoot become modified into microsporophylls and
megasporophylls which bear ovules and anthers respectively.
3. Assertion: Geitonogamy is genetically similar to autogamy.
Reason: The pollen grains come from the same plant.
2 – Marks Questions
1. Define self-incompatibility. How do self-incompatible plants pollinate?
2. Each pollen grain in the flowering plants produces male gametes. State the function of the
male gametes.
3. What are the stages of post-fertilization in plants?
4. Difference between apomixis and parthenocarpy?
5. Draw a diagram of a mature microspore of an angiosperm. Label its cellular components only.
3 – Marks Questions
1. Explain the pollination occurring in the chasmogamous flowers.
2. Describe the structure of the embryo sac of a mature angiosperm. Explain the role of
synergids in it.
3. Differentiate between Geitonogamy and allogamy.
4. List the advantages of pollination to angiospermic plants.
5. Differentiate between microsporogenesis and megasporogenesis.
5 – Marks Questions
1. Explain the formation of an embryo sac with diagrams.
2. Draw a labelled diagram of an anther lobe at the microspore mother cell stage. Mention the
roles of different wall layers of one anther.
3. Draw a labelled diagram of the sectional view of a mature pollen grain in angiosperm. Explain
the functions of its two different parts.
Human Reproduction
1 Marks MCQs
1. The hormone that is released from the testes is.
a. Testosterone
b. Progesterone
c. Vasopressin
d. Oestrogen
2. After ovulation Graafian follicle regresses into
a. corpus atresia
b. corpus callosum
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c. corpus luteum
d. corpus albicans
3. Which part of the sperm plays an important role in penetrating the egg membrane ?
a. Allosome
b. Autosome
c. Acrosome
d. Tail
4. The uterus is single and it is also called
a. fimbriae
b. ampulla
c. womb
d. isthmus
5. The finger like projections is the infundibulum are called
a. Fimbriae
b. Ampulla
c. Isthmus
d. none of the above
Assertion & Reason
1. Assertion: The testes are situated outside the abdominal cavity within the scrotum.
Reason: Muscles in the scrotum helps to maintain the low temperature of the testes,
necessary for spermatogenesis.
2. Assertion: Infundibulum is a funnel-shaped part closer to the ovary.
Reason: The edges of the infundibulum help in collection of the ovum after ovulation.
3. Assertion: Spermatogenesis starts at the age of puberty.
Reason: There is a significant increase in level of gonadotropin releasing hormone at puberty.
2 – Marks Questions
1. How is a primary oocyte different from a secondary oocyte?
2. What is the foetal ejection reflex? How does it cause parturition?
3. Write the main functions of each of the testis and ovary?
4. Draw a labelled diagrammatic view of the human male reproductive system.
5. Name and explain the role of the inner and middle walls of human uterus.
3 – Marks Questions
1. Draw a diagram of a mature human sperm. Label any three parts and write their functions.
2. Differentiate between spermatogenesis and spermiogenesis.
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