refresh与be back on one's feet的区别

Question

refresh与be back on one's feet的区别

Answer 1

to generate haploid spermatids. The mature sperm has a tail, a nucleus containing haploid chromosomes, and a front end with an acrosome, the storage site for enzymes that will aid fertilization.
精子产生过程，即精子发生在睾丸中。精子产生于输精管壁的性母细胞（精原细胞）。精原细胞经有丝分裂再减数分裂产生单倍体精子细胞，即精母细胞。成熟精子有尾部，单倍体染色体组，头部有顶体，内部储存酶类，有助于受精。