Which of the following resulted from a genetic variation that was favored by natural selection?

A. cancer in a lab rat

B. the long neck of a giraffe

C. the small size of a Chihuahua

D. smoothness of a river rock

What is the name of the outermost layer that forms a boundary around the outside of a cell?

Obesity puts a strain on the heart because

In the process of clear cutting, only mature trees are removed from an area. a. True b. False

This mild type 1 disease is caused by body's reaction to inhaled allergens.

The internal environment of a house is to thermostat as the human body is to a) skin b) pancreas c) liver d) hypothalamus

Is a fossil still a fossil if it is preserved artificially? For example, (Is a mummy a fossil even though it was preserved by people?)

Which type of macromolecule is the quickest source of energy for the body

Which two structures contain DNA

When reproduction is achieved through meiosis and subsequent fertilization it is called?

Which statement is correct? A. Both plants and fungi undergo photosynthesis. B. Both protists and fungi are eukaryotic. C. Like some prokaryotes, fungi are autotrophic. D. Both animals and fungi lack cell walls.