Exam 23: Evolution of Genes and Genomes

Refer to the figure. Genome size varies widely among different multicellular organisms.The greatest contributing cause of this variation is the amount of _______.

Most mutations in studies using in vitro evolution are introduced from

In a phylogenetic tree of primates, a gene involved in the production of brain peptides shows 25 silent substitutions but only 4 missense substitutions.From these results, we can infer that

Nonsynonymous substitutions, synonymous substitutions, and pseudogenes have different rates of evolution, on average.Which order correctly represents those rates, from fastest to slowest?

Consider the case of in vitro evolution used to generate RNA molecules with ligase activity.What is the primary source of selection?

Consider the case of in vitro evolution used to generate RNA molecules with ligase activity.If the researchers used a DNA polymerase in the PCR that was more accurate, which of the following would be most likely?

In the absence of purifying and positive selection, the ratio of the rate of synonymous substitutions to the rate of nonsynonymous substitutions should be near

Below are sequences of part of a gene taken from three species of plants. Plant A: AGATCTACGCGCAGTTTC Plant B: AGATTAGGCGCAGTATC Plant C: AGATTAGGCGCAGTTTC To align these sequences, one should add a gap to species

The two mechanisms that produce concerted evolution both rely upon _______ to occur.

The nucleotide at a position in a DNA sequence changes from C to A to C.This is an example of a _______ substitution.

Biased gene conversion would tend to _______ the amount of _______.

Refer to the figure, which shows a phylogenetic tree of the engrailed gene family. Which gene is the same evolutionary distance from zebrafish En1b as is zebrafish En2b?

The human genome contains _______ protein-coding genes.

Two species of grasshoppers have the same neutral mutation rate for any particular gene, but species A has a population size that is ten times the size of species B.The substitution rate in species A should be _______ that of species B.

In a eukaryote, one would expect to find the lowest rate of nonsynonymous nucleotide substitutions in an

Refer to the table, which shows the genome sizes, development times, and population sizes of four species of salamanders. These salamander data are consistent with

Many more synonymous than nonsynonymous substitutions have occurred in insects in the gene sevenless, which is involved in eye development.This gene is most likely under _______ selection.

Under the conditions of an experiment, a particular virus has an expected substitution rate of 1 substitution per 5,000 nucleotides per generation and a genome size of 10,000 nucleotides.If the virus has one generation per hour, we would expect approximately _______ substitutions between 9 am on Monday and 1 pm on Friday of the same week.

The voltage-gated sodium channels of neurons are membrane proteins that play a fundamental role in the generation of action potentials.Blockage of their activity by toxins, such as tetrodoxin, causes paralysis.To determine which nucleotides confer resistance to tetrodoxin in puffer fish and other resistant animals, researchers can _______ the sodium channel genes of resistant and nonresistant animals.

Kimura's _______ theory of molecular evolution proposes that most molecular variations in natural populations are selectively equivalent.