Lecture 15 - Chromosome structure and genome organization - part 2

Question 1

A genome is

Answer 1

an organism’s complete set of genes

Question 2

Generally, higher organisms (plants, animals) have _______ genomes

Answer 2

larger

Question 3

The human genome has approximately how many base pairs?

Answer 3

3 x 10^9

Question 4

Genomic data indicate that the apparent number of genes roughly parallels

Answer 4

the organism’s complexity

Question 5

Only about _____% of the genome encodes proteins

Answer 5

1.2

Question 6

A gene can be identified by its

Answer 6

homology to a previously described mRNA or protein sequence

Question 7

A protein-coding gene may also be identified as a(n)

Answer 7

open reading frame (ORF)

Question 8

A ORF is

Answer 8

a sequence without stop codons

Question 9

ORFs exhibit the same codon-usage preferences as

Answer 9

other genes in the organism

Question 10

Computer-based gene identification algorithms rely on

Answer 10

sequence alignments with expressed sequence tags (ESTs)

Question 11

ESTs are

Answer 11

cDNAs that have been reverse-transcribed from mRNAs

Question 12

The functions of many human genes have been identified through

Answer 12

sequence comparisons of protein families and domains

Question 13

The human genome contains approximately the same number of ___________ genes as other eukaryotes

Answer 13

“housekeeping”

Question 14

The human genome contains relatively more genes for ________ than other eukaryotes

Answer 14

vertebrate-specific activities (immune system, neuronal, hormonal signaling pathways)

Question 15

Nearly ______% of genes have unknown functions

Answer 15

42

Question 16

Genes with no known functions are called

Answer 16

orphan genes

Question 17

A significant portion of the human genome is transcribed to

Answer 17

RNA

Question 18

About 4000 genes have been identified for

Answer 18

tRNAs, rRNAs, and other small RNAs

Question 19

10,000s of genes have been identified for

Answer 19

noncoding RNAs (ncRNAs)

Question 20

Protein-coding genes almost never occur in

Answer 20

multiple copies

Question 21

Repeated translation of a few mRNA transcripts provides

Answer 21

adequate amounts of most proteins

Question 22

Eukaryotic genomes contain

Answer 22

repetitive DNA sequences

Question 23

Telomeres are composed of

Answer 23

repeating DNA sequences

Question 24

p arm

Answer 24

short arm structure of chromosome

Question 25

q arm

Answer 25

long arm structure of chromosome

Question 26

centromere

Answer 26

constricted point of the chromosome

Question 27

Nearly identical sequences approximately 10 bp long are ____________ in clusters of >10^6 copies per haploid genome

Answer 27

tandemly repeated

Question 28

Short tandem repeats (STRs) make up about what % of the human genome

Answer 28

3%

Question 29

STRs appear to have arisen by

Answer 29

template slippage during DNA replication

Question 30

STRs exhibit a high degree of

Answer 30

length polymorphism

Question 31

STRs analysis is widely used for

Answer 31

DNA fingerprinting

Question 32

Moderately repetitive sequences arise from

Answer 32

transposons

Question 33

~______% of the human genome consists of three types of retrotransposons

Answer 33

42

Question 34

Three types of retrotransposons

Answer 34

1. Long interspersed nuclear elements (LINEs) 2. Short interspersed nuclear elements (SINEs) 3. Retrotransposons with long terminal repeats (LTSs)