On average, adolescents need how many hours of sleep each night for proper growth and brain development?

A. 12

B. 9

C. 5

D. 7

The number of urban areas worldwide has been decreasing due to lack of resources. True False

The outer layer of a human cell allows some substances to pass through but keeps other substances out. what is the name of this layer? a. cytoskeleton b. cytoplasm c. membrane d. skin

Darwin was the only scientist to propose a theory of evolution a. True b. False

What has the most influence on the zone of inhibition of an antibiotic, antiseptic, or disinfectant?

The tendency toward having twins appears to be inherited from the

What do a door and a venus flytrap leaf have in common

Where would be the best place to find an alpine glacier A) Antarctica B) Greenland C) the Himalayas D) the North Pole

The Sun is A. a very small star. B. a medium-sized star. C. the largest star in the universe. D. the same size as all the other stars.

6. The blood component that has the greatest affinity for oxygen is the a) Lymphocyte" (b) Leucocytes (c) Erythrocytes (d) Thrombocyte

According to the endosymbiosis theory scientist believe early eukaryotes form from prokaryotes why do scientist believe that prokaryotes existed earlier eukaryotes