Frog cards have a chamber where the deoxygenated blood can mix with oxygenated blood. what structure would prevent this mixing

Which of the following protists gets nutrients mainly by absorbing molecules from other organisms through their cell walls and cell membranes? a. amoebas b. water molds c. ciliates d. slime molds

Ablastocyst is a group of cells that forms after a human egg is fertilized. the blastocyst consists of two types of cells. some of these cells will become the placenta. what do the other cells develop into?

What can be found in every skeletal muscle? a. nerves, bones, cartilage, and connective tissue b. tendons, cartilage, nerves, and blood vessels c. muscle fibers, nerves, connective tissue, and blood vessels d. tendons, nerves, blood vessels, and bones