input: OPTIONS:
- psoriasis
- marrow deficiency
- arthritis
- osteoporosis Now, answer this question: Answer the following question given this paragraph: Regular weight-bearing exercise can reduce the risk of osteoporosis. Apply lesson concepts to explain why. Q: Regularly performing weight-bearing exercise can reduce the risk of what condition that affects bones? A:
A:
output: osteoporosis

Answer the following question given this paragraph: Q: What bodily structures consist of the endothelium and its basal lamina? A:

OPTIONS:
- veins
- muscles
- fibers
- capillaries

Answer: capillaries

Problem: OPTIONS:
- Hydras choose
- Temperature rise
- Spring
- conditions improve
Q: Answer the following question given this paragraph: Q: When conditions deteriorate, hydras can reproduce sexually, forming resistant zygotes that remain dormant until when? A:
Answer: conditions improve

Problem:OPTIONS:
- clitoris
- anus
- skin
- epididymis

Answer the following question given this paragraph: Which of the following statements about the male reproductive system is false? a. The vas deferens carries sperm from the testes to the penis. Sperm mature in seminiferous tubules in the testes. Both the prostate and the bulbourethral glands produce components of the semen. The prostate gland is located in the testes. Sperm mature in seminiferous tubules that are coiled inside the testes, as illustrated in Figure 43.8. The walls of the seminiferous tubules are made up of the developing sperm cells, with the least developed sperm at the periphery of the tubule and the fully developed sperm in the lumen. The sperm cells are mixed with "nursemaid" cells called Sertoli cells which protect the germ cells and promote their development. Other cells mixed in the wall of the tubules are the interstitial cells of Leydig. These cells produce high levels of testosterone once the male reaches adolescence. When the sperm have developed flagella and are nearly mature, they leave the testicles and enter the epididymis, shown in Figure 43.8. This structure resembles a comma and lies along the top and posterior portion of the testes; it is the site of sperm maturation. The sperm leave the epididymis and enter the vas deferens (or ductus deferens), which carries the sperm, behind the bladder, and forms the ejaculatory duct with the duct from the seminal vesicles. During a vasectomy, a section of the vas deferens is removed, preventing sperm from being passed out of the body during ejaculation and preventing fertilization. Semen is a mixture of sperm and spermatic duct secretions (about 10 percent of the total) and fluids from accessory glands that contribute most of the semen's volume. Sperm are haploid cells, consisting of a flagellum as a tail, a neck that contains the cell's energy-producing mitochondria, and a head that contains the genetic material. Figure 43.9 shows a micrograph. Q: Where do sperm go after leaving the testicles and before entering the vas deferens? A:
****
A: epididymis

Answer the following question given this paragraph: Radioactivity is quantified by measuring the number of decay processes per unit time. For example, we can measure radioactivity in terms of counts per minute (cpm), where each "count" is a single decay process, such as the emission of an -particle. A sample of one particular isotope may have an activity of 5,000 cpm, while an equal amount of another isotope might result in a radiation level of only 250 cpm. For a given nucleus, the amount of radioactivity gives a rough indication of the amount of the radioisotope present the higher the activity, the more of the radioactive isotope in the sample. Q: What is quantified by measuring the number of decay processes per unit time? A:
OPTIONS:
- temperature
- microwave power
- fossil age
- radioactivity
radioactivity

Answer the following question given this paragraph: Since life began on Earth, there have been several major mass extinctions. If you look closely at the geological time scale, you will find that at least five major mass extinctions have occurred in the past 540 million years. In each mass extinction, over 50% of animal species died. The total number of mass extinctions could be as high as 20. Q: What events, resulting in death of over half of animal species, have occurred on earth at least five times in the past 540 million years? A:
OPTIONS:
- mass migrations
- microevolutions
- spontaneous mutations
- mass extinctions

Answer:
mass extinctions