Chapter 20: Genomics and Proteomics

Question 1

genomics

Answer 1

content, oraganization, function, and evolution of genetic information within whole genomes
- structural, functional, comparative

Question 2

structural genomics

Answer 2

organization and sequence of information within genomes

Question 3

functional genomics

Answer 3

function of the information within genomes

Question 4

comparative genomics

Answer 4

compares genomes of different organisms

Question 5

genetic maps

Answer 5

provide a rough approximation of the location of genes relative to the locations of other known genes
- measured in cM
- linkage analysis

Question 6

physical maps

Answer 6

based on direct analysis of DNA, places genes in relation to distances measured in number of base pairs, kilo bases, or megabases
- restriction mapping
- more accurate than genetic maps

Question 7

single nucleotide polymorphisms (snips)

Answer 7

single base pair differences in a DNA sequence between individuals of a species
- arise through mutation
- most do not result in a different phenotype

Question 8

orthologs

Answer 8

homologous genes found in different species that evolved from the same gene in a common ancestor

Question 9

paralogs

Answer 9

homologous genes in the same species that arise by duplication of a single gene in the evolutionary past
- alpha and beta subunit genes

Question 10

microarrays

Answer 10

used to study the expression of numerous genes
- DNA fragments are used as probes to find complementary sequences
- RNA is extracted from cells and reverse transcription in the presence of a labeled nucleotide produces cDNA molecules with a fluorescence tag
- tagged cDNA will pair with any complementary probe
- after hybridization, the color of the dot indicates the relative amount of mRNA in the sample
- a microarray can be constructed with thousands of different DNA probes

Question 11

heat map

Answer 11

visual representation of a continuous variable, like the expression of a gene
- red might represent over expression, green might represent underexpression
- scan of microarrays is often converted to this

Question 12

genome wide mutagenesis screen

Answer 12

can be used to search for all genes affecting a particular function or trait
- random mutations are induced in a population of organisms, creating new phenotypes
- mutated individuals are then mated with the wild type
- a few of the offspring will be heterozygous for the mutations
- they are screened for any mutant phenotypes that might be the products of dominant mutations expressed in the heterozygous fish
- recessive can be revealed with further breeding

Question 13

multigene family

Answer 13

group of evolutionarily related genes that arose through repeated duplication and evolution of an ancestral gene

Question 14

gene deserts

Answer 14

large chromosomal regions with no protein encoding genes

Question 15

transposable elements

Answer 15

highly repetitive sequences that can move around and insert into DNA

Question 16

protein microarrays

Answer 16

large number of proteins are applied to a solid support in an orderly array of spots, which each spot containing a different protein
- each spot contains an antibody for a different protein labeled with a tag that glows when bound
- extract of tissue is applied tot he microarray
- a spot of fluorescence appears when a protein in the extract binds to the antibody indicating the presence of a particular protein in the tissue