Which statement correctly describes the circulatory system?

a) blood leaves the heart via the atrium.
b) blood travels away from the heart in the pulmonary vein.
c) blood travels back to the heart in the aorta.
d) blood travels away from the heart via the pulmonary trunk.

Many kangaroo rats live in the sonoran desert of the southwestern united states. they have a variety of adaptations for living in the desert. under which circumstance would the kangaroo rats of the sonoran desert be most likely to develop new adaptations by natural selection?

What are the doorways into and out of cells, attached to the membrane, and built in the rough er.

Choose one animal (cheetas) and research on the internet what has contributed to this animal becoming "endangered" or "threatened." what animal you have chosen? 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.