The plant parts which consist of two generations -
one within the other:
A. Pollen grains inside the anther
B. Germinated pollen grain with two male gametes
C. Seed inside the fruit
D. Embryo sac inside the ovule
AI-generated explanation. Check against your textbook.
Explanation:
The phrase “two generations - one within the other” refers to a gametophyte (haploid generation) developing inside the sporophyte (diploid) structure. Pollen grains contain the male gametophyte inside the anther, and embryo sac (within the ovule) contains the female gametophyte. Both A (pollen grains inside the anther) and D (embryo sac inside the ovule) represent the gametophytic generation inside the sporophytic tissue, as described in NCERT. B is about a germinated pollen grain producing two male gametes, which is about development inside a pollen tube, not a separate generation within a structure. C (seed inside the fruit) involves a sporophyte embryo inside a seed, not a separate gametophyte generation within another structure.
🧠 Did You Know?
In angiosperms, the flowering plant body (sporophyte) surrounds the gametophytes found inside the pollen grain and the ovule.
💡 NCERT Memory Line:
Gametophyte generation is found inside the sporophyte in both pollen grain and embryo sac.
Which of the following hormone levels will cause
release of ovum (ovulation) from the graffian
follicle?
AI-generated explanation. Check against your textbook.
Explanation:
Ovulation is triggered by a surge in luteinising hormone (LH) from the anterior pituitary, which is caused by a high level of estrogen released by the graphsian (mature) follicle as the follicular phase peaks. Thus, a high concentration of estrogen induces the LH surge leading to ovulation. The other options are incorrect: progesterone rises after ovulation, not before; low LH or low FSH does not trigger ovulation.
🧠 Did You Know?
In the menstrual cycle, estrogen rises during the follicular phase and peaks just before ovulation, causing the LH surge that releases the egg.