Testosterone is an example of a steroid. Its physiological functions include:
1. Determines the the gender of a developing embryo.
2. Development of reproductive organs and the prostrate gland in males.
3. Responsible for secondary sexual characteristics in males such as deeper pitch, increased muscle bulk, hair on the upper lip.
4. Regulates normal sperm development.
Another steroid is cholesterol. Physiological functions include:
1. Helps maintain the structure of cells and vessels improving overall health and function in the body.
2. Precursor to important sex hormones such as testosterone and estrogen.
3. Used as an insulator around nerves and is absolutely essential for brain function.
4. Precursor to Vitamin D, which supports a healthy immune and nervous system
Answer:
B) increased exchange surface provided by their membranes
Explanation:
Alveoli are tiny air sacs that are responsible for exchanging oxygen (O2) and carbon dioxide (CO2) in the lungs. Alveoli have elastic fibers in order to expand and recoil depending on the volume of air breathed in. The alveolar epithelial cells (pneumocytes) may adopt a shape that serves to increase the surface area of gas exchange. On the other hand, intestinal epithelial cells have microvilli, which are microscopic projections in the plasma membrane. Microvilli serve to increase the cell's surface area, thereby facilitating the absorption of nutrients and water.
They are called the mesenteries. They are also called the mesenterium, they are peritoneal fold attaching to the small intestine to the dorsal body wall.In humans it wraps around the pancreas and the small intestine and extensions down around the colon and the upper portion of the rectum. Their function is to anchor the small intestine to the walls of the abdominal walls.
The answer is B. Meiosis involves two cycle of cell division.
