Biology Review (PDF)

(1) Human Reproductive Pathway Which part of the male reproductive pathway contains the seminiferous tubules and what is their function? The seminiferous tubules are located in the testes. Their function is to produce sperm through the process of spermatogenesis and to secrete testosterone. Which...

(1) Human Reproductive Pathway Which part of the male reproductive pathway contains the seminiferous tubules and what is their function? The seminiferous tubules are located in the testes. Their function is to produce sperm through the process of spermatogenesis and to secrete testosterone. Which part of the female reproductive pathway assists with the movement of a non-motile egg? The fallopian tubes (oviducts) assist with the movement of a non-motile egg. The cilia lining the fallopian tubes generate a current that moves the egg toward the uterus. (2) Menstrual Cycle What are the functions of the four hormones that guide the menstrual cycle? Follicle-Stimulating Hormone (FSH): Stimulates follicle growth in the ovaries and promotes estrogen production. Luteinizing Hormone (LH): Triggers ovulation and stimulates the formation of the corpus luteum. Estrogen: Thickens the endometrial lining and regulates FSH and LH levels via feedback mechanisms. Progesterone: Maintains the endometrial lining for potential implantation and inhibits further ovulation. What are 2 hormonal events of the Luteal Stage? 1. Progesterone secretion by the corpus luteum peaks, maintaining the uterine lining. 2. Estrogen levels rise to assist with uterine lining support, while FSH and LH are inhibited through negative feedback. Describe the negative feedback loop for testosterone production? What is meant by a negative feedback loop? A negative feedback loop maintains homeostasis by reducing the output of a process when its levels are sufficient. In testosterone production: The hypothalamus releases GnRH, which stimulates the pituitary to secrete LH and FSH. LH stimulates testosterone production in the testes. High testosterone levels inhibit GnRH and LH release, reducing further testosterone production. (3) STIs Is hepatitis a bacterial or viral STI? Hepatitis is a viral STI. What is the difference between the ways that bacterial and viral STIs are treated? Bacterial STIs: Treated with antibiotics (e.g., penicillin for syphilis). Viral STIs: Managed with antiviral medications (e.g., antivirals for herpes) but cannot be cured. (4) Human Development What is meant by the critical period of human development? The critical period is a time during which specific organs and structures form and are highly sensitive to external influences, such as teratogens, that can cause developmental defects. What stage of human development can be described as a hollow ball of identical cells? Where is this structure located in the female reproductive pathway? The blastocyst is a hollow ball of cells. It is located in the uterus, where it implants into the endometrial lining. (5) Extra-Embryonic Membranes What is the function(s) of the chorion? The chorion facilitates gas exchange and nutrient transfer between the mother and the embryo and forms part of the placenta. What membrane is involved with the “breaking of water”? The amnion, which contains the amniotic fluid, ruptures during the "breaking of water." (6) Teratogens How do teratogens impact the child if mom’s blood supply is separate? Teratogens, such as drugs or alcohol, can cross the placenta and interfere with fetal development, leading to physical or mental abnormalities, despite the separate blood supply. What is the impact of alcohol on human development? Alcohol can cause Fetal Alcohol Spectrum Disorders (FASD), characterized by growth deficiencies, facial abnormalities, and cognitive impairments. (7) Trimester Events What are the three trimesters of pregnancy? 1. First Trimester: Organogenesis, where major organs begin to form. 2. Second Trimester: Rapid growth and detailed organ development. 3. Third Trimester: Growth and maturation of organs, including fat deposition for thermoregulation. In what trimester does the child’s digestive and respiratory systems mature? The digestive and respiratory systems mature during the third trimester. (8) Stages of Childbirth Describe the events during the dilation stage of childbirth? The dilation stage involves: 1. Cervical dilation to 10 cm. 2. Regular contractions that widen the cervix. 3. Effacement (thinning) of the cervix. Discuss the positive feedback loop for childbirth. What is meant by a positive feedback loop? A positive feedback loop amplifies a process. In childbirth: The baby’s head pressing on the cervix triggers oxytocin release. Oxytocin stimulates uterine contractions, pushing the baby further. This cycle continues until delivery. (9) Monitoring Health of Fetus Describe a physical method of monitoring the health of the fetus? Ultrasound uses sound waves to create an image of the fetus, allowing for assessment of growth, position, and physical abnormalities. Describe a genetic method of monitoring the health of the fetus? Amniocentesis involves extracting amniotic fluid to test for genetic abnormalities like Down syndrome. (10) Causes of Infertility What is the difference between sterility and infertility? Sterility: Permanent inability to conceive. Infertility: Difficulty conceiving after a year of trying but not necessarily permanent. Discuss a blockage that can lead to male and female infertility. Explain why this leads to infertility. Male: Blockage in the vas deferens prevents sperm from exiting. Female: Blockage in the fallopian tubes prevents the egg and sperm from meeting. (11) Solutions to Infertility What solution to infertility is likely used if the female has an abnormal endometrium? A blockage in the oviduct? Discuss these solutions. Abnormal Endometrium: Surrogacy, where another woman carries the pregnancy. Oviduct Blockage: In vitro fertilization (IVF), where fertilization occurs outside the body, and the embryo is implanted into the uterus. What solution to infertility is likely if the male has low sperm count? Intracytoplasmic sperm injection (ICSI), where a single sperm is injected into an egg during IVF, is a common solution. (12) Stem Cells What is a stem cell? What is the goal of stem cell research? A stem cell is an undifferentiated cell that can develop into specialized cell types. The goal of stem cell research is to regenerate damaged tissues and treat diseases like Parkinson’s and diabetes. What is an advantage and a disadvantage of using an adult stem cell (your own)? Advantage: No immune rejection as it is from the same individual. Disadvantage: Limited differentiation potential compared to embryonic stem cells. (13) Birth Control Methods What is a hormonal method of birth control? The oral contraceptive pill, which uses hormones like estrogen and progesterone to prevent ovulation. What is a barrier method of birth control other than the condom? A diaphragm is a barrier method placed over the cervix to block sperm entry.