Which blood vessels have thin walls and contain valves?

A. Veins

B. Capillaries

C. Arteries

D. Platelets

A word that describes the movement of people into a country is? A. migration B. immigration C. irrigation D. emigration

Air pollution in US National Parks is effecting the environment in what way (s) ?

In the leaf of a plant, guard cells control the opening and closing of stomata. Which of the following do you predict would happen if the guard cells did not function properly and caused the stomata of a plant to remain closed? a.

How would an organisms homeostasis be affected if it was not able to produce enzymes

Carriers of the sickle-cell allele (i. e. those with a heterozygous genotype) are fittest in environments with high frequencies of:

8. In the S-Phase of the cell cycle; DNA is replicated. Why would eukaryotic cells need to replicate DNA before the nucleus divides? A. To trigger genetic transfer of DNA. B. To encourage rapid mutation rates in the organism. C.

The patient has been placed on a nitroprusside drip for the treatment of a hypertensive crisis. which mechanism of action does the nurse know is true for nitroprusside?

How many oxygen molecules (O₂) are required each time a molecule of glucose (C₆H₁₂O₆) is completely oxidized to carbon dioxide and water via aerobic respiration,? A) 1 B) 3 C) 6 D) 12 E) 30

Which of the following sentences are correct? (1) for millions of years dinosaurs ruled the earth; they roamed freely over the land and through the oceans.

2. A flower arranger is growing some flowers in a garden. He has seeds for red, and seeds for pink plants. Both colours are found or the same allele as each other. Red is the dominant colour, while pink is recessive.