Exam 9: How Genes and Genomes Evolve

The pufferfish, Fugu rubripes, has a genome that is one-tenth the size of mammalian genomes.Which of the following statements is NOT a possible reason for this size difference?

Which of the following statements about the globin gene family is TRUE?

Figure 9-52 shows a hypothetical phylogenetic tree.Use this tree to answer the following questions. Figure 9-52 A.How many years ago did species M and N diverge from their last common ancestor? B.How much nucleotide divergence is there on average between species M and N? C.Are species M and N more or less closely related to each other than species P and S are? D.In looking for functionally important nucleotide sequences, is it more informative to compare the genome sequences of species M and N or those of species M and Q?

Which of the following statements about what we have learned by comparing the modern-day human genome to other genomes is TRUE?

Viral genomes

The yeast genome was sequenced more than 20 years ago, yet the total number of genes continues to be refined.The sequencing of closely related yeast species was important for validating the identity of short (less than 100 nucleotides long) open reading frames (ORFs) that were otherwise difficult to predict.What is the main reason that these short ORFs are Difficult to find without the genomes of other yeast for comparison?

Given the evolutionary relationship between higher primates shown in Figure 9-18, which of the following statements is FALSE? Figure 9-18

A.When a mutation arises, it can have three possible consequences: beneficial to the individual, selectively neutral, or detrimental.Order these from most likely to least likely. B.The spread of a mutation in subsequent generations will, of course, depend on its consequences to individuals that inherit it.Order the three possibilities in part A to indicate which is most likely to spread and become overrepresented in subsequent generations, and which is most likely to become underrepresented or disappear from the population.

Consider a gene with a particular function.Mutation X and mutation Y each cause defects in the function of the encoded protein, yet a gene containing both mutations X and Y encodes a protein that works even better than the original protein.The odds are exceedingly small that a single mutational event will generate both mutations X and Y.Explain a simple way that an organism with a mutant gene containing both mutations X and Y could arise during evolution.

Which of the following situations would facilitate the process of exon shuffling?

Which of the following generalities about genomes is TRUE?

The nucleotide sequences between individuals differ by 0.1%, yet the human genome is made up of about 3 × 10⁹ nucleotide pairs.Which of the following statements is FALSE?

Which of the following functions do you NOT expect to find in the set of genes found in all organisms on Earth?

You isolate a pathogenic strain of E.coli from a patient and discover that this E.coli strain is resistant to an antibiotic.Common laboratory strains of E.coli are not resistant to this antibiotic, nor are any other previously isolated pathogenic E.coli strains.However, such resistance has been observed in other bacteria in the hospital in which the patient was treated.This newly discovered antibiotic resistance in E.coli is most likely due to

Which of the following statements about the human genome is FALSE?

You are interested in finding out how the budding yeast Saccharomyces cerevisiae is so good for making bread and have collected five new related species from the wild.You sequence the genomes of all of these new species and also consult with a fungal biologist to help you construct the phylogenetic tree shown in Figure 9-19.You find that species V, W, and X make pretty good bread whereas species Y and Z do not, suggesting that the last common ancestor of species X and S.cerevisiae may have the genes necessary for making good bread.You compare the gene sequences of species X and S.cerevisiae and find many identical coding sequences, but you also identify nucleotides that differ between the two species.Which species would be the best to examine to determine what the sequence was in the last common ancestor of species X and S.cerevisiae? Figure 9-19

Which of the following processes is NOT thought to contribute to the diversity in the genome seen between any two human individuals?

Which of the following statements is FALSE?

HIV is a human retrovirus that integrates into the host cell's genome and will eventually replicate, produce viral proteins, and ultimately escape from the host cell.Which of the following proteins is not encoded in the HIV genome?