Which characteristic is necessary for natural

selection to occur in a species?

(1) stability

(2) variation

(3) complex cellular organization

(4) a very low mutation rate

How do phagocytes protect the body? A. They produce fever, which slows germ growth. B. They produce mucus that traps germs. C. They increase blood flow to infected areas. D. They eat infected and foreign cells.

Cells in multicellular organisms that respond to a chemical signal from other cells in the same organism are called

A researcher observing an ecosystem describes the amount of sunlight, precipitation and type of soil present. Which factors is the researcher most likely describing? Biotic factors in a forest. Biotic factors in a tundra.

What is the priority nursing intervention for a client injured by lightning?

What function is performed by both goblet cells and lacrimal glands? A. digestion B. stress regulation C. protection D. growth regulation

Conduction of nerve impulses is possible because of the

What is one similarity between replication and transcripton

Fossils on the continent may be similar to fossils on another continent. This observation supports which theory?

Jane filled one transparent bottle and one brown bottle of the same capacity with pond water. She kept the first bottle in sunlight and the second in dark. After one hour she calculated the amount of oxygen present in both the bottles.

The kingdom contains all autotrophic organisms.