Which nucleotide in figure 13-1 indicates the nucleic acid in RNA?

1. guanine

2. uracil

3. cytosine

4. adenine

How many amino acids exsist

Eubacteriaudents research unicellular, prokaryotic organisms that live in harsh environments such as volcanic hot springs, brine pools, and anaerobic black organic mud.

How does a plant lose water in the night

Human development is a complex process. Where does human development occur? A. in a structure of the female urinary system B. in a structure of the female digestive system C. in a structure of the female circulatory system D.

A scientific theory is A. a hypothesis that has been rigorously tested and never been disproven. B. a hypothesis that has been rigorously tested and only been disproven a few times. C. an opinion. D.

When a female bird chooses a mate because of his brightly colored feathers, this is an example of A) random mating, which maintains equilibrium in the gene pool. B) sexual selection, which alters allele frequencies in the gene pool.

What statement does NOT pertain to the cephalic phase of gastric secretion? (It controls the rate at which chyme enters the small intestine., It is triggered by sensory input, such as sight, as well as mental input, such as thinking about food.

Which is not a source of noise pollution

What process is involved in over irrigation that results in the reduction of soil fertility? A) Water penetrates the deep soil layers and dissolves the salt present there. B) Salt accumulates near the surface of the soil.

Explain why the two alleles, ia and ib, that produce the ab blood type are said to be codominant.