Sexual Reproduction
Understandings:
• A gene on the Y chromosome causes embryonic gonads to develop as testes and secrete testosterone.
• Testosterone causes pre-natal development of male genitalia and both sperm production and development of male secondary sexual characteristics during puberty.
• Estrogen and progesterone cause pre-natal development of female reproductive organs and female secondary sexual characteristics during puberty.
• A gene on the Y chromosome causes embryonic gonads to develop as testes and secrete testosterone.
• Testosterone causes pre-natal development of male genitalia and both sperm production and development of male secondary sexual characteristics during puberty.
• Estrogen and progesterone cause pre-natal development of female reproductive organs and female secondary sexual characteristics during puberty.
• Skill: Annotate diagrams of the male and female reproductive system to show names of structures and their functions.
Understandings:
• 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: Spermatogenesis results in 4 sperm cells from one germ cell (spermatogonium). Oogensis results in 3 polar bodies and 1 ovum (received majority of the cytoplasm) from the germ cell (oogonium). |
Development of the embryo:
• Implantation of the blastocyst 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.
Cleavage --> Gastrulation --> Neurulation --> Organogenesis
• Implantation of the blastocyst 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.
Cleavage --> Gastrulation --> Neurulation --> Organogenesis
Aim 8: Scientists are aware that the drugs women take in fertility treatment pose potential risks to health.
ToK: Should scientific knowledge override compassionate considerations in treating infertile couples?
ToK: Should scientific knowledge override compassionate considerations in treating infertile couples?