Which of the following ratios of nucleotides is constant for DNA? a. A+ U = G+C
b. A + G =T + C
C. A + C = U + G
d. A + T = G + C

The diagram shows a fossil of an ancient whale skull and a skull of a present-day whale. the ancient whale is extinct and is believed to be an ancestor of the present-day whale. what do these skulls most likely show that supports darwin’s theory of evolution? all populations can adapt and survive. only some organisms have a common ancestor. populations change slowly over time. populations rapidly become extinct.

If a cell is placed into a hypertonic environment, what will happen to it ? a)it will shrink or shrivel b)nothing c)it will burst d) it will expand or enlarge

The genetic code is essentially the same for all organisms. based on this information, one can logically assume which of the following statements to be correct? a. dna was the first genetic material. b. the same codons in different organisms translate into the different amino acids. c. different organisms have different numbers of different types of amino acids. d. a gene from an organism can theoretically be expressed by any other organism. e. all organisms have experienced convergent evolution.