quiz review

1. What hormone controls body temperature? 

   1. thyroxine (produced by the thyroid gland), which influences metabolism and heat production

   2. The hypothalamus is the part of the brain that regulates body temperature by activating mechanisms like sweating or shivering in response to temperature changes.

2. What are the parts of and functions of the nephron?

   1. Glomerulus: Filters blood to form urine.

   2. Bowman’s Capsule: Collects filtrate from the glomerulus which it encases.

   3. Renal Tubule: Reabsorbs water, nutrients, and ions; secretes waste.

   4. Loop of Henle: Creates a concentration gradient in the medulla, allowing for water reabsorption.

   5. The nephron's primary functions include filtration of blood to form urine, reabsorption of essential nutrients and water, secretion of waste products, and regulation of electrolyte balance and blood pressure.

3. What is ADH and what is its function?

   1. ADH (Antidiuretic Hormone) aka vasopressin is produced by the hypothalamus and released by the posterior pituitary gland. It helps regulate water balance/reabsorption in the kidneys by increasing the permeability of the collecting ducts, resulting in reduced urine volume and more concentrated urine. It helps regulate osmolarity and blood pressure

4. How do desert plants osmoregulate? 

   1. Reducing water loss through thick cuticles, closing stomata during the hottest part of the day and waxy layers: Help reduce transpiration

   2. CAM Photosynthesis: They fix carbon dioxide at night to minimize water loss during the hot day.

   3. Modified stomata: Stomata may be closed during the day to prevent water loss and can open at night when temperatures are cooler.

   4. Water Storage: They store water in thick stems or other tissues to endure long periods of drought.

C4 plants fix CO2 during the day, CAM plants at night

5. How does the body respond to changes in temperature?

Heat:

 Vasodilation: Blood vessels expand, increasing blood flow to the skin for heat loss.

Sweating: Sweat glands activate to release moisture, which cools the body via evaporation.

Cold:

Vasoconstriction: Blood vessels constrict to reduce blood flow to the skin, conserving heat.

Shivering: Muscles contract rapidly to generate heat.

Hormonal Response: Increased thyroxine secretion increases metabolic activity, generating more heat.

6. Know the menstrual cycle (hormones and process)..

The menstrual cycle is approximately a 28-day cycle divided into phases:

Follicular Phase (Days 1-13): FSH (Follicle Stimulating Hormone) stimulates ovarian follicles.

Estrogen is produced by developing follicles.

Ovulation (Day 14): Surge in LH (Luteinizing Hormone) triggers the release of the mature egg.

Luteal Phase (Days 15-28): Corpus luteum forms and secretes progesterone and estrogen to maintain the uterine lining.

If fertilization doesn’t occur, hormone levels drop, leading to menstruation

7. What is HCG, molecules that bind to it, and what is its function?

   1. HCG (Human Chorionic Gonadotropin) is a hormone produced during pregnancy. It binds to receptors on the corpus luteum to maintain progesterone production, preventing menstruation.

8. How does the body regulate blood sugar levels?

   1. Insulin: Lowers blood sugar levels by facilitating glucose uptake by cells, released by the pancreas, promoting glycogenesis (conversion of glucose to glycogen) in the liver.

   2. Glucagon: Raises blood sugar levels by promoting the release of glucose from liver stores. secreted by the pancreas, stimulating glycogenolysis (conversion of glycogen back to glucose) and gluconeogenesis (production of glucose from non-carbohydrate sources).

9. insulin decreases blood sugar by promoting glucose uptake, while glucagon increases it by stimulating the liver to release stored glucose

10. What are the functions of female hormones?

    1. Estrogens: Promote the development of female secondary sexual characteristics, regulate the menstrual cycle, and maintain pregnancy.

    2. Progesterone:helps prepare the inside of the uterus (the endometrium) for a fertilized egg to implant. If pregnancy occurs, progesterone supports early pregnancy by maintaining that uterine lining. Regulates the menstrual cycle.

    3. Luteinizing Hormone (LH): Triggers ovulation and influences the development of the corpus luteum - temporary endocrine gland that forms in the ovary after ovulation

    4. Follicle Stimulating Hormone (FSH): Stimulates follicle (small sacs that contain eggs) development and estrogen production in the ovaries.

11. What are the processes of spermatogenesis and oogenesis?

    1. Spermatogenesis: Production of sperm in the testes; involves meiosis and results in four viable sperm.

    2. Oogenesis: Production of eggs in the ovaries; involves meiosis and results in one viable egg and three polar bodies, which degenerate

12. What are the parts of a human egg and what are their functions? 

Parts of a human egg (ovum) include:

1. Cytoplasm: Contains nutrients and organelles for early development.

2. Nucleus: Contains genetic material (DNA).

3. Zona Pellucida: Thick outer layer that protects the egg and facilitates sperm binding.

4. Cell Membrane: Encloses the egg

5. Corona Radiata: A layer of follicular cells that provide nutrients to the egg.

13. How does the body carry out excretion? (include removal of CO2 as well as urine) How does this compare to single cell organisms?

body excretes waste through:

Kidneys: Filtering and removing waste as urine.

Lungs: Exhaling CO2 produced from cellular respiration.

In single-celled organisms, excretion occurs via simple diffusion across the cell membrane directly into the environment, via diffusion or osmosis, eliminating waste like CO2 and ammonia without specialized organs.