When did the last mass extinction occur?

O

A. At the beginning of this era.

O

B. At the beginning of this period.

O

C. At the beginning of this epoch.

O

D. At the beginning of this eon.

What are the functions of the cardiovascular system?

What is a multi-chambered shell

What would happen if a nucleotide was added at the fourth location in the chain

Which division of the nervous system calms the body after an emergency has passed?

Alteration of Generations is when plants alternate between two forms called a. gametophyte and haploid b. sporophyte and diploid c. gametophyte and sporophyte d. meiosis and fertilization

An organisms ability to maintain its proer condition

1 Chromosomes move to the middle of the cell during what phase?

A change in a gene due to damage or incorrect copying is called a evolution. c. segregation. b. meiosis. d. a mutation.

The risk of injury in a car accident is much greater if occupants do not wear a seat belt. Wich of newton's laws explains why this is true? A. Law of inertia B. Law of force and acceleration. C. Law of action-reaction D. Law of gravity

Why does the United States experience winter during the months of November through early March