Question

4 multiple choice 2.5 points the second meiotic division of meiosis returns the chromosome number to diploid before fertilization. allows for crossing over and random distribution of chromosomes. reduces cell size by dividing the cytoplasm in half. prevents chromosome copies from doubling at each fertilization. is a step required for fertilization to take place.

Explanation:

1. Analyze Option 1: The second meiotic division (meiosis II) doesn't return to diploid; meiosis I reduces to haploid, and meiosis II maintains haploid. Fertilization restores diploid. So this is incorrect.
2. Analyze Option 2: Crossing over and random distribution (independent assortment) occur in meiosis I, not meiosis II. So this is incorrect.
3. Analyze Option 3: In meiosis II, after the first division (which reduces chromosome number), the second division (like mitosis of haploid cells) involves cytokinesis that divides the cytoplasm, reducing cell size by splitting it in half (e.g., in oogenesis, polar bodies or in spermatogenesis, forming smaller sperm cells). This matches the process of meiosis II.
4. Analyze Option 4: Preventing chromosome doubling at fertilization is the role of meiosis (overall, reducing to haploid), but specifically meiosis II doesn't have this as its main role. Meiosis I is more about reducing chromosome number. So this is incorrect.
5. Analyze Option 5: Meiosis II is not a "required step for fertilization to take place" in the sense that fertilization can occur with haploid cells from meiosis I? No, actually, meiosis II is part of gamete formation, but the statement is not accurate. Fertilization requires haploid gametes, which are produced after meiosis (both I and II), but the wording here is off. The key is that Option 3 correctly describes a process in meiosis II (cytokinesis dividing cytoplasm, reducing cell size).

Answer:

The option "reduces cell size by dividing the cytoplasm in half." (the third option among the choices)