Biology 1201-Ch.21 Quiz

What was the main goal of the Human Genome Project (HGP)?

to map all the human genes and determine the nucleotide sequence of the entire human genome

BLAST is a computational tool used by genome biologists to _____.

compare a given DNA or protein sequence to all other DNA or protein sequences in a database

Which of the following statements about genome sizes is true?

Most eukaryotes have larger genomes than most prokaryotes.

The number of genes correlates with _____.

the size of the genome in prokaryotes

What type of noncoding DNA comprises the largest portion of multicellular eukaryotic genomes?

transposons

How do retrotransposons differ from other transposons?

Retrotransposons move via an RNA transcript, whereas other transposons do not.

How has gene duplication played a critical role in evolution?

It produces redundant copies of existing genes, which are then free to mutate and adopt new functions.

By what mechanism might transposons contribute to gene duplication?

Transposons may promote unequal crossing over during meiosis.

What is the goal of comparative genomic studies?

to identify homologues in model organisms for genes involved in human disease, to identify genes that are important for evolution of a particular species, to study how genomes evolve, to study genetic variation within a species or a population

What are Hox genes?

Hox genes encode transcription factors with a DNA-binding domain called a homeo box, and regulate development of the vertebrate body plan.

For mapping studies of genomes, most of which were far along before 2000, the three-stage method was often used. Which of the following is the usual order in which the stages were performed, assuming some overlap of the three?

linkage map, physical map, sequencing of fragments

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