Reproduction in Organisms — NEET UG practice

1. Recall the unusual sex determination system in honeybees: in honeybees, males (drones) develop from unfertilized eggs and are haploid, while females (queens and workers) develop from fertilized eggs and are diploid.

2. Understand how each sex produces gametes: since the female honeybee is diploid, she must reduce her chromosome number by half to form gametes, so she uses meiosis. Given this,

3. Consider the male honeybee's situation: since the male is already haploid, he cannot undergo meiosis (which requires a diploid starting cell to halve the chromosome number); instead, his haploid cells divide by simple mitosis to directly produce haploid gametes (sperm). Therefore,

4. Eliminate the other options: male earthworms, male frogs, and male grasshoppers are all diploid organisms and produce gametes through the standard process of meiosis, not mitosis.

Hence, the correct answer is A. Male honeybees.

1. Start with the first signal in the hormonal cascade: the process begins in the brain, where the hypothalamus releases (B) Gonadotropin releasing hormone (GnRH).

2. Trace the next step, the pituitary response: GnRH travels to and stimulates the anterior pituitary gland to release (E) Gonadotropins — namely LH and FSH. Given this,

3. Follow the action of LH: one of these gonadotropins, LH, acts on the Leydig cells in the testes, so (A) LH stimulates synthesis and secretion of Androgen.

4. Follow what androgen then does: the androgen produced (mainly testosterone) then directly stimulates the process of sperm formation, so (C) Androgen stimulates spermatogenesis.

5. Add the final step involving FSH: separately, the other gonadotropin, FSH, acts on Sertoli cells to help in (D) spermiogenesis — the transformation of spermatids into mature sperm. Putting it all together,

Hence, the correct sequence is (B), (E), (A), (C), (D), so the answer is C.

1. Recall what placentation means: placentation refers to the specific arrangement of ovules within the ovary of a flower, and there are several distinct types.

2. Recall the definition of axile placentation: in axile placentation, the ovary is multi-locular (has multiple chambers), and the placenta forms along the central axis, with ovules attached to it. Given the examples in the option,

3. Note the other placentation types for contrast: Dianthus and Primrose show free central placentation (ovules on a central axis without septa); Pea, Lupin, and Beans show marginal placentation (ovules along the fused margin of a single carpel); Cucumber and Mustard show parietal placentation (ovules on the inner wall of the ovary).

4. Eliminate the other options based on this: option A mixes axile (China rose) with marginal examples (Beans, Lupin); option B mixes axile (Tomato, Pea is actually marginal) with free central (Dianthus); option D lists parietal (Mustard, Cucumber) with free central (Primrose) examples — none of these are all axile.

Hence, the correct answer is C. China rose, Petunia and Lemon.