How many different codons can code for the amino acid tryptophan (Trp) ? A) 1 B) 3 C) 4 D) 6

A certain species of lizard can have orange stripes, green stripes, or orange and green stripes. An GG lizard has orange stripes, a gg lizard has green stripes, and a Gg lizard has orange and green stripes.

Which of the following best describes the climates of Europe and North America during the 1.8 million years of the Quaternary period? A. Hot and Dry B. Cool and Rainy periods followed by droughts C. Warm and Mild D.

Which system allows for food to be broken down and made available for a chipmunk's body to use? a. digestive system b. excretory system c. endocrine system d. respiratory system

What is created from mitosis in animals? a. two identical nuclei b. egg and sperm cells c. gametes that are identical d. four identical nuclei

A student using a light microscope observes a cell and correctly decided that it is

Select the correct statement about antigens. A. One antigen may have many different antigenic determinants and may therefore cause the formation of more than one antibody. B. Only small antigens exhibit reactivity. C.

Which molecule is the source of basic material used for the production of glucose in the calvin cycle?

Why do cells need to be able to transport substances across their membrane

Which is a characteristic of all waves?

What does the heart do?