In a DNA molecule, which of the following forms a base pair with adenine?

O A. Cytosine

O B. Guanine

O C. Thymine

O D. Adenine

What information can scientists learn by comparing gene and protein sequences from different organisms?

What two amino acids are coded for by an mRNA segment reading CUA AGG

A client who is at 10 weeks' gestation returns for her second prenatal visit. she asks why she has to urinate so often. the nurse tells her that urinary frequency in the first trimester is

When the atria contract, which of the following is true? a. The AV valves are closed. b. The ventricles are in diastole. c. The atria are in diastole. d. The semilunar valves are open.

How long can an infant go without oxygen?

What does food supply all living things with for life activities?

An 8-year-old has scabs and fluid-filled vesicles on her face, throat and stomach. Three weeks earlier she had visited her grandmother who had shingles. What infection does the 8-year-old have

Tropical forests contain dense trees, which allow less sunlight to penetrate. Emergent trees are trees that grow to a height of more than 45 to 55 meters, above the usual height of trees in tropical forests.

B. Explain Why do communities change over time

Cells that protect the body by engulfing foreign cells or producing antibodies are a. red blood cells b. cilia c. platelets d. white blood cells