Midterm (Exam 1)

Question 1

responsible for strong negative charge of nucleic acid

Answer 1

phosphate group

Question 2

semiconservative replication of DNA

Answer 2

parental double helix divides into two double helix DNA with one parental strand in each of the two double helices

Question 3

eukaryotic DNA

Answer 3

long and multiple origins of replication

Question 4

single stranded DNA binding proteins

Answer 4

helix destabilizing proteins: keep the two DNA strands separate and protects against Nucleases that cleave single stranded DNA

Question 5

DNA polymerase lll has a

Answer 5

5’ –> 3’ polymerase activity

Question 6

3’ –> 5’ exonuclease

Answer 6

excise mismatched nucleotides during proofreading of newly synthesized DNA

Question 7

DNA polymerase l activity uses

Answer 7

• 5’ –> 3’ exonuclease activty for RNA primers
• new DNA in 5’ –> 3’ polymerase direction
• proovereads new chain in 3’ –> 5’ exonuclease

Question 8

pol alpha

Answer 8

multisubunit enzyme for eukaryotic DNA replication to initiate strand synthesis on the leading strand and beginning of okazaki fragments of lagging strand

Question 9

unlike DNA polyermase, RNA polyermase doesn’t require a

Answer 9

primer and has no endo/exonuclease activity –> no mistmatch repair

Question 10

RNA polymerase produces

Answer 10

small RNA’s: tRNA and rRNA

Question 11

degeneracy

Answer 11

redundant genetic code where some amino acids have more than one triplet coding for it

Question 12

Huntington disease

Answer 12

autosomal dominant

Question 13

galactosemia

Answer 13

autosomal recessive disorder

Question 14

locus heterogeneity

Answer 14

same disease phenotype by mutations at different loci

Question 15

genomic imprinting

Answer 15

differential activation of genes, depending on parent

Question 16

genomic imprinting example

Answer 16

• mutation on long arm of chromo 15 from father –> prader willi syndrome
• mutation on long arm of chromo 15 from from mother –> angelman syndrome

Question 17

• GAA triplet

- intron

Answer 17

Friedreich ataxia

Question 18

site of expansion and affected sequence caused by nucleotide repeat mutation; autosomal recessive

Answer 18

Friedreich Ataxia

Question 19

1 in 800 live births

Answer 19

trisomy 21

Question 20

most common chromsomal abnormality among still-borns which produces Edward syndrome

Answer 20

Trisomy 18

Question 21

associated with Klinefelter syndrome

Answer 21

Trisomy XXy (Kayrotype 47)

Question 22

Isochromosomes

Answer 22

chromosomes divide perpendicular to normal axis of division

Question 23

Isochromosomes results in a chromosome that

Answer 23

has 2 copies of one arm and no copies of the other

Question 24

Isochromosomes makes genetic material that is

Answer 24

substantially altered so most are lethal

Question 25

most Isochromosomes observed in live births involve

Answer 25

the X, so features of Turner syndrome

Question 26

MC inherited cause of mental retardation

Answer 26

Fragile X syndrome

- X exhibits breaks/gaps new long arm tip

Question 27

permutations tend to become larger in successive generations

Answer 27

Sherman paradox

Question 28

mitochondrian inheritance disease that causes progressive degen of pigment layer of retina, cardiac conduction abnormalities, ataxia, deafness, and dementia.

Answer 28

Kearns-Sayer syndrome

Question 29

Familial hypercholesterolemia

Answer 29

autosomal dominant

Question 30

hemophilia A

Answer 30

X-linked recessive

Question 31

Glucose-6-phosphatase defect

Answer 31

Ian on Gierke Disorder in the liver

Question 32

most prevalent amino acid metabolism disorder

Answer 32

PKU

Question 33

Maple Syrup Urine disease results from deficiency in

Answer 33

branched-chain a-ketoacid dehydrogenase

Question 34

what doesn’t occur in the nucleus

Answer 34

translation

Question 35

7-sterol reductase deficiency (Smith-Lemi-Opitz) is in cholesterol biosynthesis results in

Answer 35

decrease levels of cholesterol and increased 7-dehydrocholesterol

Question 36

increase levels of cholesterol and increased 7-dehydrocholesterol leads to

Answer 36

congenital anomalies of the brain, heart, genitalia and hands

Question 37

urea cycle disorders include

Answer 37

hyperammonemia and ornithine transcarbamoylase

Question 38

hyperammonemia causes

Answer 38

mental retardation, coma, and death

Question 39

ornithine transcarbamoylase is the only

Answer 39

X-linked enzyme, others are autosomal recessive

Question 40

Lyon hypothesis

Answer 40

one X chromosome in each cell is randomly inactivated early in the embryonic development of females

Question 41

dosage compensation

Answer 41

females with two copies of the X chromo will produce X-linked gene products similar to males

Question 42

X-linked dominant inheritance patterns

Answer 42

50% sons affected and 50% daughters affected

Question 43

d-linked recessive inheritance patterns

Answer 43

50 % of sons affected and 50% of daughters heterozyous carriers

Question 44

trisomy 13 produces

Answer 44

Patau syndrome

Question 45

karyotype 45, X produces

Answer 45

Turner syndrome (female)