What is the single greatest environmental cause of human illness?

Common signs and symptoms of acute hyperventilation syndrome include

What is biology? what are the studies in it?

Sea otters have been used as an example of the keystone species concept. This means that sea otters

The body is able to resist pathogens because

How long ago did the common ancestor of bears and cats live

The mitochondrial DNA sequences of a large extended family were analyzed and compared to a single male in the family. Which of the relatives' mitochondrial DNA should be a match to this person?

How do you explain that the variability in a domesticated species is greater than in the same species, or a similar one, in the wild? For example: dogs vs. wolves; chickens vs. red jungle fowl.

Which of the following traits do archaeans and bacteria share? A) composition of the cell wall B) lack of a nuclear envelope C) presence of plasma membrane D) both A and B E) both B and C

In a population of birds, the percentage of individuals having a certain gene changes from 20% to 60% over the span of several hundred years.

How many codons equal an amino acid?