Spermatogenesis and oogenesis both involve mitosis, cell growth, two divisions of meiosis and differentiation.
Processes in spermatogenesis and oogenesis result in different numbers of gametes with different amounts of cytoplasm.
Fertilization in animals can be internal or external.
Fertilization involves mechanisms that prevent polyspermy.
Implantation of the blastocysts in the endometrium is essential for the continuation of pregnancy.
HCG stimulates the ovary to secrete progesterone during early pregnancy.
The placenta facilitates the exchange of materials between the mother and fetus.
Estrogen and progesterone are secreted by the placenta once it has formed.
Birth is mediated by positive feedback involving estrogen and oxytocin.
The average 38-week pregnancy in humans can be positioned on a graph showing the correlation between animals’ size and development of the young at birth for other mammals.
Annotation of a diagram of seminiferous tubule and ovary to show the stages of gametogenesis.
Annotations of diagrams of mature sperm and egg to indicate functions.
Nature of Science
Assessing risks and benefits associated with scientific research-the risks to human male fertility were not adequately assessed before steroids related to progesterone and estrogen were released into the environment as a result of the use of female contraceptive pill.