Why can black holes not be seen?

They have too much gravity for light to escape.

They are hidden in interstellar dust.

They exist only behind other stars.

Scientists don't know where to look for them.

Define target cell and explain why all cells are not target cells for all hormones

Why did mosquitoes develop resistance to DDT? A. Because it was killing them so they had to do something! B. The government reduced their use of DDT after the book Silent Spring and the mosquitoes used the time to develop defenses against DDT. C.

What fibrous structure functions to anchor the atrioventricular valves in a closed position?

True or False Individuals evolve by developing traits that are better for survival and reproduction

Voluntary control over your skeletal muscles happens with what part of the nervous system? A. somatic B. sympathetic C. parasympathetic D. autonomic

In living things, smaller substances are linked to make up larger substances. Which of the following correctly describes a larger substance made by linking smaller substances? Nucleic acids are linked to make up proteins.

Describe the environment in Madagascar

Example of a food chain of which fungi is a part?

Environmental manipulation can result in unforeseen consequences true or false

Why do some leaves turn yellow or orange in the fall? A) to attract beneficial insects B) because the chlorophyll pigment has broken down D) because the carotenoid pigment has increased