Where is oxygen content in a river or stream likely to be highest?

a.

the source

b.

the mouth

c.

the middle portion

d.

none of the above

Which statements describe a human-created mass extinction? Select three correct choices. It results from the disappearance of entire species in a short time. It results from the disappearance of a few organisms in a short time.

In all food webs, what is the ultimate source of energy?

Joshua needs to clean his dog every week to remove the ticks from the dog's body. What kind of interaction do Joshua's dog and the ticks have? A. parasitism B. mutualism C. interference competition D. predation

What enzyme found in saliva breaks chemical bonds between the sugar monomers in starches? a. amylase c. pepsin b. chyme d. hydrochloric acid

This is a type of protein found in a cell membrane which regulatesthe coming and going of substances into or out of the cell

A mother is fertile but unable to conceive. an egg taken from the mother and sperm from the father are combined in a laboratory. the embryo is then placed in the mother's uterus. what is this called?

Which of the following is the correct definition of radiant energy? A. energy that is transmitted in the form of electromagnetic waves B. energy created by sound waves C. energy an object has because of its motion or position D.

How many chromosomes do we get from each parent?

As sales tax is s type of

Which foods should be minimized in the diet of an athlete managing gastroesophageal reflux disease (GERD) ?