Final answer:
Pseudoautosomal regions (PARs) are sections on the X and Y chromosomes that are identical in sequence, allowing these sex chromosomes to pair and recombine during meiosis, behaving similarly to Regions of DNA that behave like autosomes option (b).
Step-by-step explanation:
Pseudoautosomal regions (PARs) are specific areas on the X and Y chromosomes in humans and other mammals where the sequences of nucleotides are almost identical. Despite the general difference in the genetic content and function of these two sex chromosomes, PARs allow for the X and Y chromosomes to pair and recombine during meiosis, which is the process by which sex cells, or gametes, are formed.
While the X chromosome carries a considerable number of genes, the Y chromosome is much smaller and contains fewer genes. To facilitate the critical process of recombination during meiosis, the PARs on both chromosomes behave like autosomes, which are the non-sex chromosomes present in both males and females. This is essential for proper segregation of the sex chromosomes during the formation of sperm cells in males.
Therefore, the correct answer to the question 'What are Pseudoautosomal regions?' is (b) Regions of DNA that behave like autosomes. These regions are crucial for ensuring that both the X and Y chromosomes are correctly distributed during the production of male gametes.