Which way do the nitrogenous bases in dna pair up?

a) a and g; t and c
b) a bad c; t and g
c) a and t; g and c
d) a and a; t and t and g; c and c

Which description provides the best objective summary of the article in the passage?

The normal shape of an enzyme is as shown in structure a. if the enzyme’s shape changes to that shown in structure b, what are two consequences of this change?

Which of the following factors would not contribute to allopatric speciation? a) a population becomes geographically isolated from the parent population. b) the separated population is small, and genetic drift occurs. c) the isolated population is exposed to different selection pressures than the ancestral population. d) different mutations begin to distinguish the gene pools of the separated populations. e) gene flow between the two populations is extensive.