Bio Final Ch. 18

The movement of these blocks suggests that

chromosomal translocations have moved blocks of sequences to other chromosomes.

Bioinformatics includes all of the following except

using molecular biology to combine DNA from two different sources in a test tube.

The pie chart in Figure 18.1 represents the relative frequencies of the following in the human genome: I. repetitive DNA unrelated to transposons II. repetitive DNA that includes transposons III. unique noncoding DNA IV.introns and regulatory sequences V. exons 1) Which region is occupied by exons only (V)?

A

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

Crickets must have more noncoding DNA.

Which region includes Alu elements and LI sequences?

E

Which of the following is a representation of gene density?

Humans have ~20,000 genes in 2,900 Mb.

When does exon shuffling occur?

during meiotic recombination

In order to determine the probable function of a particular sequence of DNA in humans, what might be the most reasonable approach?

Look for a reasonably identical sequence in another species, prepare a knockout of this sequence in that species, and look for the consequences.

Humans have 23 pairs of chromosomes. In contrast, chimpanzees have 24 pairs of chromosomes and lack any pair resembling the long human chromosome 2 pair; instead, chimpanzees have two pairs of medium-sized chromosomes. What is the most likely explanation for these differences in the human and chimpanzee genomes?

The common ancestor of humans and chimpanzees had 24 pairs of chromosomes, and at some point in the human lineage, two chromosomes fused end to end, providing some selective advantage.

What characteristic of short tandem repeat DNA makes it useful for DNA fingerprinting?

The number of repeats varies widely from person to person or animal to animal.

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

There should also be persons whose hemoglobin contains two copies of the series of amino acids that is deleted in hemoglobin Lepore.

A recent study compared the H. 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. The data that suggested this were

a number of modern H. sapiens with Neanderthal sequences.

Two eukaryotic proteins are identical except for one domain in each protein, and these two domains are completely different from each other. Which of the following processes is most likely to have contributed to this difference?

alternative splicing

Multigene families include two or more nearly identical genes or genes sharing nearly identical sequences. A classical example is the set of genes for globin molecules, including genes on human chromosomes 11 and 16. 1) How might identical and obviously duplicated gene sequences have gotten from one chromosome to another?

by chromosomal translocation

Which procedure is not required when the shotgun approach to sequencing is modified as sequencing by synthesis, in which many small fragments are sequenced simultaneously?

cloning each fragment into a plasmid

Which of the following most correctly describes the whole-genome shotgun technique for sequencing a genome?

cloning fragments from many copies of an entire chromosome, sequencing the fragments, and then ordering the sequences

A microarray known as a GeneChip, with most of the human protein-coding genetic sequences, has been developed to aid in the study of human cancer by first comparing two to three subsets of cancer subtypes. What kind of information might be gleaned from this GeneChip to aid in cancer prevention?

data that could alert patients to what kind of cancer they were likely to acquire

Several of the different globin genes are expressed in humans, but at different times in development. What mechanism could allow for this?

differential gene regulation over time

Homeotic genes

encode transcription factors that control the expression of genes responsible for specific anatomical structures.

Two eukaryotic proteins have one domain in common but are otherwise very different. Which of the following processes is most likely to have contributed to this similarity?

exon shuffling

A multigene family is composed of

genes whose sequences are very similar and that probably arose by duplication.

In humans, the embryonic and fetal forms of hemoglobin have a higher affinity for oxygen than that of adults. This is due to

nonidentical genes that produce different versions of globins during development.

Which of the following can be duplicated in a genome?

sequences, chromosomes, or sets of chromosomes

What is metagenomics?

sequencing DNA from a group of species from the same ecosystem

Homeotic genes contain a homeobox sequence that is highly conserved among very diverse species. The homeobox is the code for that domain of a protein that binds to DNA in a regulatory developmental process. Which of the following would you then expect?

that homeotic genes are selectively expressed over developmental time

Which of the following represents another example of the same phenomenon as that shown in Figure 18.2?

the apparent centric fusion between two chromosome pairs of primates such as chimps to form the ancestor of human chromosome 2

What is bioinformatics?

the application of computational methods to the storage and analysis of biological data

The comparison between the number of human genes and those of other animal species has led to many conclusions, including that

the number of proteins expressed by the human genome is far more than the number of its genes.

What is proteomics?

the study of the full protein set encoded by a genome

One of the characteristics of retrotransposons is that

they code for an enzyme that synthesizes DNA using an RNA template.

Fragments of DNA have been extracted from the remnants of extinct woolly mammoths, amplified, and sequenced. These can now be used to

understand the evolutionary relationships among members of related taxa.