Which part of the heart takes blood from the veins and pumps it into a ventricle?

A. ventricles

B. valves

C. arteries

D. atria

What is the impact of Hurricane Katrina on the aquatic ecosystem?

How do scientists count a species' population?

What are the many conditions that are kept the same in an experiment

DNA replication is a process that involves copying the DNA molecule. If a single base was miscopied, what would be a possible result of this for the cell in which it happened?

What is a closed curculatory system

In what part of cell does replication occur

What factors influence the impact a population has on its environment?

What kind of bonds form between the oxygen atoms of one water molecule and the hydrogen atoms of another water molecule

Salamanders brought into a new ecosystem that is colder than its all ecosystem the salamander cannot survive in the cold temperature in days which is the best way to describe a salamander in the new ecosystem

Trace a drop of blood from the left atrium to the left hallucinating and back to the right atrium