Genes and Chromosomes

Question 1

what is short arm of chromatid called?

Answer 1

p arm

Question 2

what is the long arm of chromatid called?

Answer 2

q arm

Question 3

what is chargaff’s rule

Answer 3

purines = pyrimidines

A + G = T + C

Question 4

what is complementary strand of

5’ CGGTACT 3’

Answer 4

5’ AGTACCG 3’

Question 5

what can anti parallel strand of DNA be used for?

Answer 5

primer for PCR or ASO probe for mutation detection

Question 6

are both introns and exons transcribed and translated?

Answer 6

introns and exons are both transcribed but only exons are translated

Question 7

purpose of alternative splicing

Answer 7

to form different proteins from one gene

Question 8

name some regulatory sequences and what do they do

Answer 8

enhancers, silencers, promoters

they regulate the rate of transcription

Question 9

how does methylation (an epigenetic modification) affect transcription

Answer 9

the more methylated, the less effective transcription is

Question 10

makeup of DNA

Answer 10

nuclear, extragenic DNA (repetitive), and mitochondrial

Question 11

where is highest gene density

Answer 11

subtelomeric region

Question 12

noncoding region of DNA

Answer 12

centromere, telomere, and heterochromatic region

Question 13

what is nuclear coding DNA

Answer 13

unique single copy genes and multigene families

Question 14

difference between single gene and multigene

Answer 14

single gene - codes for only one protein

multigene - genes with similar functions that have arisen by gene duplication

Question 15

what is extragenic DNA

Answer 15

the other 98% of our DNA that is not transcriptionally active and appears nonfunctional

might play a role in regulation of gene expression

Question 16

importance of STR (short tandem repeats)

Answer 16

fingerprinting (microsatellite)

Question 17

polymorphic and inherited in a codominant fashion

Answer 17

STR (short tandem repeats)

VNTR (variable number of tandem repeats)

Question 18

subgroups of tandem repeats

Answer 18

satellite, minisatellite, microsatellite

Question 19

satellite DNA are usually clustered around?

Answer 19

centromeres of chromosomes

Question 20

importance of telomeres

Answer 20

necessary to prevent shortening of chromosomes

Question 21

previously used for fingerprinting

Answer 21

hypervariable minisatellite (VNTR)

Question 22

appears to be normal RNA converted back to DNA using reverse transcriptase then reinserted back into genome

~10% of human genome

Answer 22

short interspersed nuclear element (SINE)

Question 23

might be responsible for mutation because of unequal crossover during meiosis

Answer 23

LINE and SINE

Question 24

LINEs code for what enzyme

Answer 24

reverse transcriptase

Question 25

what are pseudogenes

Answer 25

look like real genes but do not code for any protein hence nonfunctional

Question 26

mitochondrial DNA thought to have risen by?

Answer 26

endosymbiosis because it is a single, circular DNA

Question 27

how are most mitochondrial proteins encoded

Answer 27

by gene in nucleus

Question 28

A student observes the β-globin amino acid sequence, and compares it to the β-globin gene sequence. He finds that some regions are missing in the β-globin protein that is synthesized. The sequences that would be present in the protein that is synthesized are?

Answer 28

exons

Question 29

A research geneticist has identified a tetranucleotide repeat polymorphic marker, that is linked to an autosomal dominant disorder in a family. This marker belongs to the class of

Answer 29

short tandem repeats

Question 30

DNA wound around specific proteins

Answer 30

histone

Question 31

hierarchical levels of chromatin packaging in a human chromosome

Answer 31

double helix --> nucleosome fiber (beads on a string) --> solenoid ---> nucleus

Question 32

importance of metaphase

Answer 32

maximum condensation hence you see all the chromosome ...great for karyotyping

Question 33

attach to the centromere kinetochores during cell division

Answer 33

microtubules

Question 34

gene absent where

Answer 34

centromere and telomere

Question 35

when p and q arm are of equal length

Answer 35

metacentric chromosome (chromosome 1)

Question 36

when p arm is shorter than q arm

Answer 36

submetacentric chromosome (chromosome 4)

Question 37

when p arm contains little genetic information

Answer 37

acrocentric chromosome (chromosome 1, 14, 15, 21, and 22)

Question 38

largest chromosome | smallest chromosome

Answer 38

1 is largest | 21 is smallest

Question 39

when both chromosomes of a pair are derived from same parent

Answer 39

uniparental disomy

Question 40

inactivated and condensed X chromosome

Answer 40

barr body (in females)

Question 41

is the same X chromosome inactivated in all descendants of that cell or nah

Answer 41

it is!

Question 42

X-inactivation is regulated by a region called ______ that has the gene, ______ involved in inactivation

Answer 42

X-inactivation center (Xic) XIST gene

Question 43

XIST RNA coats one of the X-chromosome resulting in...

Answer 43

transcription interference

Question 44

females are said to be mosaic because

Answer 44

of X-inactivation

Question 45

what is locus of a gene

Answer 45

location on the chromosome

Question 46

Autosomal dominant disorders begin with Autosomal recessive disorders begin with X-linked disorders begin with Mitochondrial disorders begin with

Answer 46

1 2 3 5

Question 47

what is significant the p arm on acrocentric chromosome

Answer 47

it has satellite structures

Question 48

what does the mushroom alpha amanatin

Answer 48

RNA pol II