Question

model of spermatogenesis
according to this diagram, the result of spermatogenesis is four sperm cells, each with
a strands of dna that resulted from crossing over
b half of the original number of chromosomes
c genetically identical strands of dna
d complete copies of all the original chromosomes

Explanation:

Spermatogenesis involves meiosis, which reduces the chromosome number by half. The diagram shows cell divisions (meiosis I and II) leading to sperm cells. Option A: Crossing over isn't guaranteed in all sperm DNA strands. Option C: Sperm cells are genetically diverse (due to meiosis and crossing over), not identical. Option D: Sperm cells have half the original chromosomes, not complete copies. Option B correctly states each sperm has half the original chromosome number (haploid), a key result of meiosis in spermatogenesis.

Answer:

B. half of the original number of chromosomes