Sickle cell disease is caused by a:

A. change in one allele.

B. change in the size of a chromosome.

C. change in two proteins.

D. change in the number of chromosomes in a cell.

Which process occurs in an ecosystem after a lava flow has completely covered the surface of an area of land? Primary succession Edge succession Secondary succession Cyclic succession

Early taxonomists, like Linnaeus, were interested in creating diagrams to show ... evolutionary relatedness morphological similarity proposed ancestral relationships DNA similiarity

Briefly explain the four different types of acid-base disturbance found in the human body

What is one condition that must be met for a population to be in genetic equilibrium? A. There is nonrandom mating. B. There is a large amount of gene flow. C. There is no genetic drift. D. There is a high mutation rate.

One reason farmers often choose GM crops over non-GM crops is because GM crops are

A nurse is assessing a client with a diagnosis of primary open-angle glaucoma. which ocular symptom should the nurse expect the client to report?

The speed of neural impulses along an axon is increased greatly by

True or false: the northern lights are caused by earth magnetic field

Which of the following is a function of the nucleus? A) stores DNA B) stores sugars C) builds proteins D) packages proteins

Animals are motile because they have: a. energy b. metabolism c. nerve and muscle fibers d. legs or wings