What is the function of valves in veins? what is the function of valves in veins? they counteract low venous pressure, and prevent backflow of blood away from the heart. they are the reason that a relatively higher amount of blood resides in veins, compared to arteries. they propel blood with great velocity. they compensate for the larger lumens of veins compared to arteries of similar size?

Parasitism could be considered a form of which of these types of relationships? -mutualism -commensalism -predator-prey -mimicry

Research cheetahs on the internet what has contributed to this animal becoming "endangered" or "threatened." what animal you have chosen? -cheetah how long has the animal been endangered or threatened? what has contributed to this animal’s endangered or threatened status? why is it important to save this animal from extinction? after researching and gathering facts, write a 350-word letter from the point of view of an animal rights' activist. be sure to include at least five facts that you learned from your research.

What is the membrane that sheath of schwann cell containing cytoplasm and nucleus that encloses myelin