Teeth begin to break down food by mechanical digestion. Which statement best describes this physical change?

Explain how DNA, which is six feet long, can be stored in the nucleus of a tiny human cell.

Food mutagens can cause many different types of DNA damage, from single nucleotide alterations to gross chromosomal aberrations. Which of the following are known mutagens in today's conventional diet? a.

What does theory mean to a scienist?

A glucose molecule is the

Scientists from different fields are trying to understand how the global climate is reacting to the changes caused in nature, and by human activities. They have come up with conflicting interpretations.

Suppose you use a microscope to look at a cell from the leaf of a tree. What structure will you see that would not be found in a cell from your fingernail? A. mitochondria B. cilia C. cell wall D. ribosomes

Name the three energy roles that organisms fill in an ecosystem.

Adrenergic postganglionic neurons release the hormones norepinephrine and epinephrine. Adrenergic postganglionic neurons release the hormones norepinephrine and epinephrine. True False

Which of the following are examples of the first specialized tissues?

Which structure of the trachea prevents it from collapsing inward and obstructing the air passageway?