Part A Drag the labels to steps and products in spermatogenesis. Secondary spermatocytes Primary spermatocyte Mitosis of spermatogonium Spermiogenesis DNA replication Spermatids Sperm Synapsis and tetrad formation Meiosis II Meiosis I Submit Previous Answers Request Answer Reset Help
The Correct Answer and Explanation is:
Correct Order of Labels for Spermatogenesis Diagram:
From top to bottom and left to right on the image, the correct sequence of labels is:
- Mitosis of spermatogonium
- Primary spermatocyte
- DNA replication
- Synapsis and tetrad formation
- Meiosis I
- Secondary spermatocytes
- Meiosis II
- Spermatids
- Spermiogenesis
- Sperm
Explanation
Spermatogenesis is the biological process in which sperm cells are produced in the male testes. It transforms a diploid spermatogonial stem cell into four haploid spermatozoa through a series of mitotic and meiotic divisions followed by maturation.
The process begins with mitosis of a spermatogonium, a diploid germ cell. This produces two cells: one remains a spermatogonium to sustain the stem cell population, while the other becomes a primary spermatocyte.
The primary spermatocyte undergoes DNA replication during the S phase of interphase, preparing it for meiotic division. It then enters meiosis I, during which synapsis and tetrad formation occur—homologous chromosomes pair up and exchange genetic material through crossing over. This enhances genetic diversity.
Following meiosis I, the primary spermatocyte divides into two secondary spermatocytes, each with half the number of chromosomes (haploid) but still in the duplicated state.
These secondary spermatocytes quickly enter meiosis II, which resembles mitosis, where sister chromatids are separated. The result is four spermatids, each with a haploid set of chromosomes.
Though spermatids are genetically complete, they are not yet functionally mature. They undergo spermiogenesis, a maturation process in which they develop tails, lose excess cytoplasm, and form an acrosome—an organelle that helps penetrate the egg.
The final product is sperm, which are motile, structurally specialized cells capable of fertilizing an ovum. Each sperm contains a haploid nucleus, making it essential for combining with the haploid egg to form a diploid zygote.
This well-orchestrated process ensures genetic diversity and the continuity of life, reflecting both biological precision and evolutionary adaptation.
