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.

the electromagnetic energy from the sun arrives in the form of visible and invisible light.

genetic variation will increase because of a new habitat and food source.

explanation:

the potatoes have high sugar concentrations and although these potatoes were different we could seethe effects that their sugar concentrations had in different environments. for example, the potatoes in sample a, were placed in pure water. this created a hypertonic environment and caused the potatoes to draw in water from its surroundings. we saw the opposite happen with the potatoes in sample b when placed in the sodium chloride solution. the potatoes in this case were in a hypotonic solution and therefore lost water to their surroundings.