Which nucleotide bases are purines?

a. adenine & guanine

b. adenine & thymine

c. guanine & cytosine

d. cytosine& thymine

Gel electrophoresis separates dna fragments on the basis of what characteristic

Which best describes niches? A. If two species have the same niche, one species will always become extinct. B. Two species are able to occupy the same niche in the same habitat. C. Two species cannot occupy the same niche in the same habitat. D.

What is the mixture of water and other molecules found inside the cell?

Why is it impotant for scientists toknow the structure of DNA

What are the three enzymes that aid in dna replication, and what do they do exactly?

Which two combinations of alleles could produce a trait controlled by a dominant allele?

How does global climate change most directly impact marine life? Decreased ability of marine reptiles to lay eggs Decreased habitat for polar marine animals Increased marine mammal oxygen consumption Increased reproduction of marine migratory birds

Where do joint capsule receptors send proprioceptive information?

Why do scientists use controlled experiments

Which of the following show population variation? Bacteria becomes resistant to penicillin. Galapagos Island finches have different sized beaks depending on which island they are on because of the different kind of seeds available to eat on each