Exam 21: Genomes and Their Evolution

A "microarray" is a tool used in genetic research to determine the mRNAs being produced in a particular tissue, and their relative level of expression. Known genes can therefore be assayed for their expression in different situations. One use of the technology is in cancer diagnosis and treatment. If a known gene functions as a tumour suppressor, predict which of the following pieces of evidence would be most useful in diagnosis of a cancer due to a mutation in this tumour-suppressor gene.

Which of the following statements correctly describes one of the characteristics of alternative splicing in vertebrate genomes?

When gene duplication occurs to its ultimate extent by doubling all genes in a genome, which of the following results has occurred?

How do transposable elements and short tandem repeats (STRs) differ?

Why is sequencing of eukaryotic genomes more difficult than sequencing genomes of bacteria or archaea?

Which of the following statements is a correct representation of gene density?

Homeotic genes contain a homeobox sequence that is highly conserved among very diverse species. The homeobox is the code for the domain of a protein that binds to DNA in a regulatory developmental process. Which of the following statements is therefore correct regarding homeotic genes?

A current view of how the human and chimpanzee can share most of their nucleotide sequences yet exhibit significant phenotypic differences is that many of the most important sequence differences alter ________.

Based on the data in the Amino Acid Sequence Identity Table, which two members of the human globin gene family are the most divergent?

Why might the cricket genome have 11 times as many base pairs as that of Drosophila melanogaster?

Current analysis indicates that less than 2% of the human genome codes for proteins. Based on the systems approach employed by the ENCODE project, what percentage of the genome is estimated to be transcribed at some point in at least one cell type?

A sequence database such as GenBank could be used to carry out which of the following processes?

Comparisons of DNA sequences within the human species have revealed many variations. Which of the following variations involves duplication of relatively long stretches of DNA?

Which of the following statements defines proteomics?

How do transposons and retrotransposons differ in how they move around in a genome?

Which of the following statements correctly describes one characteristic of retrotransposons?

Unequal crossing over during prophase I can result in one sister chromosome with a deletion and another with a duplication. A mutated form of haemoglobin, so-called haemoglobin Lepore, exists in the human population. Haemoglobin Lepore has a deleted series of amino acids. If this mutated form was caused by unequal crossing over, what would be an expected consequence?

Which of the following processes correctly describes gene annotation in bioinformatics?

Studies in knockout mice have demonstrated an important role of the FOXP2 transcription factor in the development of vocalisations. Recent sequence comparisons of the FOXP2 gene in Neanderthals and modern humans show that while the DNA sequence may be different, the protein sequence it codes for is identical. Which of the following conclusions might logically be inferred from this information?

A recent study compared the Homo sapiens genome with that of Neanderthals. The results of the study indicated that there was a mixing of the two genomes at some period in evolutionary history. Which of the following potential discoveries of additional data might be consistent with this hypothesis?