What links the two strands in a DNA helix together in the middle?

A. Phosphate groups

B. Sugar rings bonded together

C. Proteins

D. Bases with hydrogen bonds

What is the most extreme weather in your region? What safety precautions does your family have to take because of this severe weather?

Which is evidence that scientists use to support the big bang theory? A. Most orbits have an elliptical shape. B. The outer planets are mostly composed of hydrogen and helium. C. Most galaxies are moving away from each other. D.

Select the correct text in the passage. Which quotation from "The Tell-Tale Heart" by Edgar Allan Poe brings out the theme of time?

Which of the following is NOT an example of a reflex action? A. quickly withdrawing your hand after touching a hot pan B. passing food through your digestive tract C. blinking your eye when a splinter gets into it

True or false. during sperm maturation, secondary spermatocytes are the products of meiosis ii that go on to form spermatids, which undergo restructuring to form spermatozoa.

Amino acids with hydrophobic r groups are most often found buried in the interior of folded proteins. True or False.

Which division of the plant kingdom is made up of plants that have flowers or fruit? A.) Angiosperms B.) Gymnosperms C.) Nonvascular plants D.) Seedless vascular plants

explain how the elimination of a predator from a ecosystem might result in starvation amongst its prey speies

What organs function using the photereceptors

Suppose you didn't water a plant for two weeks. What do you expect the stomata would do