Which statement best defines biodiversity?

a) the total number of different species in an area

b) the number of communities in an ecosystem

c) the number of tropic levels in a food web

d) the total size of a population of a single species

Brown mice disappear from the mouse population for two generations and then reappear in the third generation. Give two possible explanations for how they can reappear after being absent from the population.

Define the term active transport in terms of concentration gradient

Skin cancers typically develop in what layer of the dermis

Which of the following is a difficulty associated with environmental protection? a. cost b. unpredictability c. sustainability d. all of the above

Which of these organisms have the smallest amount of cell specialization? O A. Roses O B. Bacteria O c. Cats O D. Protozoans

What did Virchow observe that led him to determine one of the main components of cell theory?

Discuss the social and biological construction of race in the United states.

From what material is the block made

When water freezes, how does the ice compare to the liquid water? The ice has a greater mass and a greater volume than the water. The ice has the same mass but greater volume than the water. The ice has less mass and less volume than the water.

Angus is accused of having a restriction of range problem in his evaluations of coworkers. what is most likely to be true about angus?