Detergents, fertilizers, and raw sewage that make their way into rivers, lakes, and underground aquifers are sources of?

Which climate has summers that are short and cool; while the winters are long and very cold?

What's one reason sexual reproduction not important?

This structure produces and stores pollen ...

What would happen if the sister chromatids of one pair did not seperate during anaphase 2?

Two birds eating and nesting in same area are what?

What specific powers are given to the government under the Constitution

A scientist is investigating mutations. She observes a mutation where one or more nucleotides are inserted into a sequence of DNA. The scientist claims that this insertion mutation will affect genetic variability.

Acetylcholine is a neurotransmitter in the brain and in skeletal muscles, where it causes muscle contraction. (however, acetylcholine inhibits cardiac muscle contraction.

Each of the following statements concerning hair is true except A. scalp hairs grow constantly throughout life. B. the cortex of the hair is composed of hard keratin. C. the medulla is the soft core of the hair. D.

Some neural tissues retain stem cells and thus the capacity to divide and replace lost neurons. Which of these special senses can replace its damaged neural receptors? a) proprioception b) vision c) olfaction d) hearing e) equilibrium.