In mammals, The placenta is essential to the embryo for:

A. Nutrition, reproduction, and growth

B. Nutrition, respiration, and excretion

C. Locomotion, respiration, and excretion

D. Nutrition, reproduction, and excretion

Muscles in animals are often found in pairs, because a. muscles can only pull. b. muscles need to be able to both push and pull. c. muscles can only push. d. muscles can only produce a force as they relax.

How is cellular respiration, both anaerobic and aerobic, instrumental in muscle contractions?

How does the use of hydroelectric energy compare to the use of coal?

Suppose you have two small plants. You cut the roots off of one and then place both plants in a jar of red dye. After 20 minutes, the roots, stem, and leaves of the plant with roots have turned pink.

Explain the circumstances when a recessive trait will be expressed

Ozone hole refers to ... ? A. hole in ozone layer B. decrease in the ozone layer in troposphere C. decrease in thickness of ozone layer in stratosphere D. increase in the thickness of ozone layer in troposphere

Chemicals used in chemotherapy treatments to fight cancer can also harm cells in hair follicles and bone marrow. What characteristic do these cells most likely share with cancerous cells? A.) They form tumors. B.) They spread through the blood. C.

Binary fission is a process through which A. all cells divide. B. eukaryotic cells divide. C. prokaryotic cells divide. D. cellular DNA is cut in half.

Describe how this algal bloom might alter the local nitrogen cycle in that ecosystem.

What are the reactants in the equation for cellular respiration?