Cleaning dirty needles prior to use helps prevent the spread of HIV. When using bleach, the user must rinse out all the blood first and then fill the needle and syringe with full-strength bleach three times for to seconds.

Next pretest: evolution select the correct answer in a laboratory population of flies, the female flies are gray and the males are yellowish gray. biologists observed that all the male flies had an equal chance for reproduction, but the male flies with the brightest colors were more likely to successfully reproduce. what phenomenon could explain such a change? a sexual selection b. disruptive selection c. stabilizing selection d. directional selection

The normal shape of an enzyme is as shown in structure a. if the enzyme’s shape changes to that shown in structure b, what are two consequences of this change?

The diagram shows the development of the oocyte and the follicle during the menstrual cycle. identify at which stage in the cycle the hormone levels are at their highest and most active.