Which structures have valves to prevent blood from flowing backwards?
A) arteries
B) capillaries
C) veins
D) SA node
C
You might also like to view...
Apes and monkeys differ in two noticeable characteristics. These characteristics are that apes have
A. opposable thumbs and monkeys do not, and apes have binocular vision and monkeys do not. B. opposable thumbs and monkeys do not, and apes have tails and monkeys do not. C. binocular vision and monkeys do not, and apes have tails and monkeys do not. D. larger brains than monkeys do, and monkeys have tails and apes do not. E. opposable thumbs and monkeys do not, and monkeys have larger brain capacity than apes do.
Which of the following is NOT TRUE of
cystic fibrosis? a. It produces sticky mucus. b. It leads to increased bacterial lung infections. c. The amino acid affected is phenylalanine. d. It causes insufficient water to leave the cells. e. All of these are true.
The influenza virus can infect:a
humans b. pigs c. birds d. humans and pigs e. humans, pigs and birds
A DNA molecule that enters a bacterium by one of several mechanisms is called a(n) ________.
A. exogenote B. endogenote C. merozygote D. None of the choices are correct.