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.

How does the carbon cycle prove the law of conservation of mass?

What happens when an enzyme's structure as it exceeds the typical human body temperature

Which is not characteristics of all mammals? a. a four-chambered heart that prevents mixing of oxygenated and deoxygenated blood b. giving birth to live young (viviparous) c. having hair during at least some period of life d.

How do cells divide

Activities of the digestive system generally increase when it is stimulated by parasympathetic impulses. sensory impulses. somatic impulses. sympathetic impulses.

Which term describes this example? A child with no freckles has a mother who has freckles and is heterozygous and a father who has no freckles and is homozygous recessive. a. female b. heterozygous c. homozygous recessive d. homozygous dominant e.

At which of the following temperatures will the average energy of motion of the particles in a substance be greatest? A. - 12 C B. 0 C C. 12 C D. 20 C

In Wisconsin a very large population of lake trout in which individuals mate at random experiences no migration mutation nor selective pressure for a number of years. Which of these is most likely to occur in the population?

How much time do most experts agree is required to allow for muscle recovery before engaging in muscular strength/endurance weight lifting of the same muscle group? 6 hours 12 hours 18 hours 48 hours

What are some changes that can occur in ecosystems