In the 1840s, many Irish families grew one variety of potato for food. Suggest why a disease (potato blight) caused mass starvation in Ireland at this time.

Veins have a much lower blood pressure than arteries. which of these prevents backflow of blood in veins? a. pressure applied by the heart b. one–way valves in veins c. thin muscular walls of veins

Light sensitivity in euglena is provided by the

What is the next step in muscle contraction after the actin changes shape