Before there was life on earth, which gas was absent from the ancient atmosphere?

A. ammonia

B. methane

C. nitrogen

D. Oxygen

What does parfocal mean?

What are two important advantages of being diploid in plants?

What dangerous environmental side effect increases because of human produced carbon dioxide?

Why did one barbell have potential energy while the other did not

In pea plants, yellow seeds (y) are dominant and green seeds (y) are recessive. a pea plant with yellow seeds is crossed with a pea plant with green seeds. the resulting offspring have about equal numbers of yellow and green seeded plants.

Animal lays eggs with a tough leathery watertight shell

Why is DNA antiparallel? It has double strands complementing each other. The bases in one strand pair with the other bases in the complementary strand. It has a ladder shape. Its double strands run in opposite directions.

Which of these is a solution, where the solute and solvent are in the gas phase? A) air B) ozone C) brass D) carbon dioxide

The roads in northern states (like Michigan) need to be repaired more often than roads in southern states (like South Carolina). Explain the effects mechanical weathering could have on this?

A substance that form hydrogen ions when dissolved in water is called a?