Question 1

1. An apple farmer notices that the fleshy part of the fruit we eat is not derived from the ovary. In biological terms, what is this part?

A) EndospermB) ThalamusC) PericarpD) Mesocarp

Answer

✓ Correct Answer: Option B

Explanation: Apple is a 'false fruit' because the fleshy, edible part develops from the thalamus rather than the ovary wall. The ovary forms the core where seeds are located.

Question 2

2. A plant breeder wants to store pollen grains for several years for a hybridization program. At what temperature and in what medium should they be stored?

A) $0^\circ C$ in waterB) $-196^\circ C$ in liquid nitrogen $25^\circ C$ in dry air

Question 3

3. During a medical checkup, a woman is told her LH levels have surged suddenly on the $14^{th}$ day of her cycle. What event is most likely about to occur?

A) OvulationB) MenstruationC) ImplantationD) Menopause

Answer

✓ Correct Answer: Option A

Explanation: The LH (Luteinizing Hormone) surge triggers the rupture of the Graafian follicle and the release of the ovum, a process called ovulation.

Question 4

4. A scientist observes a seed that has developed without fertilization. This phenomenon is commonly used in the grass family to produce clonal seeds. What is it called?

A) ParthenocarpyB) Double FertilizationC) PolyembryonyD) Apomixis

Answer

✓ Correct Answer: Option D

Explanation: Apomixis is the mechanism by which seeds are produced without fertilization, effectively mimicking sexual reproduction but resulting in clones.

Question 5

5. In a fertility lab, a sperm cell is observed to have a defect in its middle piece. Which function will be most directly affected?

A) Penetration of the eggB) Genetic transmissionC) Swimming speed (Motility)D) Formation of the zygote

Answer

✓ Correct Answer: Option C

Explanation: The middle piece contains numerous mitochondria, which provide the energy (ATP) required for the movement (motility) of the tail.

Question 6

6. A gardener finds that certain flowers never open, ensuring that they always self-pollinate. These flowers are called:

A) CleistogamousB) ChasmogamousC) DioeciousD) Xenogamous

Answer

✓ Correct Answer: Option A

Explanation: Cleistogamous flowers never open. This guarantees autogamy (self-pollination) even in the absence of pollinators.

Question 7

7. In a coconut, which part represents the free-nuclear endosperm that we often drink?

A) The white kernelB) The coconut waterC) The hard shellD) The outer husk

Answer

✓ Correct Answer: Option B

Explanation: Coconut water is the free-nuclear endosperm (made of thousands of nuclei), while the white kernel is the cellular endosperm.

Question 8

8. A woman in the first trimester of pregnancy has high levels of hCG in her blood. Which organ is primarily responsible for secreting this hormone?

A) OvaryB) Pituitary glandC) PlacentaD) Uterus

Answer

✓ Correct Answer: Option C

Explanation: The placenta acts as an endocrine tissue and secretes hormones like hCG (human Chorionic Gonadotropin) to maintain the pregnancy.

Question 9

9. If a pollen grain of a plant has n = 12 chromosomes, how many chromosomes will be found in the cells of the endosperm of that plant?

A) 12B) 36C) 24D) 48

Answer

✓ Correct Answer: Option B

Explanation: In angiosperms, the endosperm is triploid (3n). If n = 12, then $$3n = 3 \times 12 = 36$$.

Question 10

10. A breastfeeding mother provides immunity to her newborn through a yellowish fluid called colostrum. Which specific antibody is abundant in it?

A) IgAB) IgGC) IgED) IgM

Answer

✓ Correct Answer: Option A

Explanation: Colostrum is rich in IgA antibodies, which are crucial for developing the infant's immune system.

Question 11

11. A corn cob has long silky 'tassels' waving in the wind. What is the biological function of these tassels?

A) To attract insectsB) To protect the seedsC) To perform photosynthesisD) To trap wind-borne pollen grains

Answer

✓ Correct Answer: Option D

Explanation: The tassels of a corn cob are actually the stigma and style which wave in the wind to trap pollen grains.

Question 12

12. In a human embryo, the blastocyst becomes embedded in the lining of the uterus. What is this process called?

A) FertilizationB) GastrulationC) ImplantationD) Cleavage

Answer

✓ Correct Answer: Option C

Explanation: Implantation is the process where the blastocyst attaches and sinks into the endometrium of the uterus.

Question 13

13. A farmer uses a hormone spray to produce seedless watermelons. This production of fruit without fertilization is known as:

A) ApomixisB) ParthenocarpyC) ParthenogenesisD) Polyembryony

Answer

✓ Correct Answer: Option B

Explanation: Parthenocarpy is the development of fruit without fertilization, resulting in seedless fruits (e.g., banana, treated watermelons).

Question 14

14. Inside a pollen grain, which cell is larger and contains abundant food reserves?

A) Vegetative cellB) Generative cellC) Male gameteD) Synergid

Answer

✓ Correct Answer: Option A

Explanation: The vegetative\ cell is the larger cell of the pollen grain and stores food. The smaller generative\ cell floats in its cytoplasm.

Question 15

15. During the follicular phase of the menstrual cycle, which primary hormone is secreted by the growing follicles?

A) ProgesteroneB) LHC) EstrogenD) FSH

Answer

✓ Correct Answer: Option C

Explanation: As follicles grow under the influence of FSH, they secrete estrogen, which helps rebuild the uterine lining.

Question 16

16. In flowering plants, the 'Filiform Apparatus' is a special cellular thickening found in which cells?

A) Egg cellB) AntipodalsC) Central cellD) Synergids

Answer

✓ Correct Answer: Option D

Explanation: The filiform\ apparatus is located at the micropylar tip of the synergids and guides the entry of the pollen tube.

Question 17

17. After ovulation, the ruptured Graafian follicle transforms into a yellow endocrine structure. What is it?

A) Corpus albicansB) Corpus luteumC) Primary follicleD) Placenta

Answer

✓ Correct Answer: Option B

Explanation: The corpus\ luteum forms from the remains of the Graafian follicle and secretes large amounts of progesterone.

Question 18

18. In a typical angiosperm embryo sac, how many nuclei are present at maturity?

A) 8B) 7C) 3D) 6

Answer

✓ Correct Answer: Option A

Explanation: A typical mature angiosperm embryo sac is 7-celled but 8-nucleated (the central cell has two polar nuclei).

Question 19

19. Which structure in the human male reproductive system provides a site for sperm maturation and storage?

A) TestisB) Vas deferensC) EpididymisD) Prostate gland

Answer

✓ Correct Answer: Option C

Explanation: The epididymis is a long coiled tube where sperm are stored and undergo physiological maturation to gain motility.

Question 20

20. A citrus fruit is found to contain many embryos in a single seed. What is this condition called?

A) AposporyB) ParthenogenesisC) Double fertilizationD) Polyembryony

Answer

✓ Correct Answer: Option D

Explanation: Polyembryony is the occurrence of more than one embryo in a seed, common in Citrus and Mango.

Accepted Answer

✓ Correct Answer: Option C

Explanation: Pollen grains can be stored for years in liquid nitrogen at a temperature of $-196^\circ C$, a technique known as cryopreservation.

Grade 12 Biology : Sexual Reproduction Quiz (Set 2)

1. An apple farmer notices that the fleshy part of the fruit we eat is not derived from the ovary. In biological terms, what is this part?

2. A plant breeder wants to store pollen grains for several years for a hybridization program. At what temperature and in what medium should they be stored?

3. During a medical checkup, a woman is told her LH levels have surged suddenly on the $14^{th}$ day of her cycle. What event is most likely about to occur?

4. A scientist observes a seed that has developed without fertilization. This phenomenon is commonly used in the grass family to produce clonal seeds. What is it called?

5. In a fertility lab, a sperm cell is observed to have a defect in its middle piece. Which function will be most directly affected?

6. A gardener finds that certain flowers never open, ensuring that they always self-pollinate. These flowers are called:

7. In a coconut, which part represents the free-nuclear endosperm that we often drink?

8. A woman in the first trimester of pregnancy has high levels of hCG in her blood. Which organ is primarily responsible for secreting this hormone?

9. If a pollen grain of a plant has n = 12 chromosomes, how many chromosomes will be found in the cells of the endosperm of that plant?

10. A breastfeeding mother provides immunity to her newborn through a yellowish fluid called colostrum. Which specific antibody is abundant in it?

11. A corn cob has long silky 'tassels' waving in the wind. What is the biological function of these tassels?

12. In a human embryo, the blastocyst becomes embedded in the lining of the uterus. What is this process called?

13. A farmer uses a hormone spray to produce seedless watermelons. This production of fruit without fertilization is known as:

14. Inside a pollen grain, which cell is larger and contains abundant food reserves?

15. During the follicular phase of the menstrual cycle, which primary hormone is secreted by the growing follicles?

16. In flowering plants, the 'Filiform Apparatus' is a special cellular thickening found in which cells?

17. After ovulation, the ruptured Graafian follicle transforms into a yellow endocrine structure. What is it?

18. In a typical angiosperm embryo sac, how many nuclei are present at maturity?

19. Which structure in the human male reproductive system provides a site for sperm maturation and storage?

20. A citrus fruit is found to contain many embryos in a single seed. What is this condition called?