Genetics and Disease Midterm 1

Question 1

Inheritance pattern and gene affected in hypercholesterolemia?

Answer 1

Autosomal dominant and mutations on LDLR gene

Question 2

What does LDL-R do?

Answer 2

Binds ApoB 100 to LDL to allow it to transport through the blood stream

Question 3

For alzheimer, what is the location for APP and PSEN 1?

Answer 3

APP- 21q11, PSEN1 14q24.2

Question 4

What type of inheritance is alzheimers?

Answer 4

Autosomal dominant

Question 5

What is the problem with Tay-Sachs

Answer 5

There is a deficiency of Hexoaminidase A that leads to accumulation of gangliosides in the central nervous system

Question 6

Tay-Sachs is biochemically considered to be _

Answer 6

Incomplete dominance

Question 7

How is hemophilia inherited?

Answer 7

X-linked recessive

Question 8

How is fragile x syndrome inherited?

Answer 8

X-linked dominant

Question 9

What gene has the mutation with fragile x?

Answer 9

FMR-1 gene is mutated

Question 10

How do you inherit cycstic fibrosis?

Answer 10

Autosomal Recessive

Question 11

What gene has the mutation for cystic fibrosis? And what does that cause?

Answer 11

CFTR gene, causes water accumulation because Cl cant move

Question 12

What is the deletion for cystic fibrosis?

Answer 12

Delta F 508, deletion of phenylalanine

Question 13

What is special about a compound heterozygote?

Answer 13

More severe than a heterozygote, less severe than a homozygote recessive

Question 14

Which strand synthesizes okazaki fragments?

Answer 14

In the lagging strand

Question 15

What are the 3 phases of DNA replication?

Answer 15

Initiation, elongation, termination

Question 16

What happens in initiation?

Answer 16

Proteins bind to DNA, open the double helix and prepare DNA

Question 17

What happens in elongation?

Answer 17

Proteins connect the sequence of nucleotides into a continuous strand of DNA

Question 18

What happens in termination?

Answer 18

Proteins release from the replication complex

Question 19

Topoisomerase:

Answer 19

Prevents torsion/breaks

Question 20

Helicase:

Answer 20

Separates 2 strands of DNA

Question 21

Primase:

Answer 21

Synthesizes RNA primers

Question 22

Single strand binding proteins:

Answer 22

Prevents reannealing of single strands

Question 23

DNA ligase:

Answer 23

Seals nicks in DNA

Question 24

DNA pol:

Answer 24

Synthesizes DNA, also functions as exonuclease in eukaryotes

Question 25

What is telomerase and what cells have it?

Answer 25

Telomerase restores telomere length to avoid loss of DNA at the end where the RNA primer was, only present in stem cells and cancer cells

Question 26

What are the short RNA sequences that DNA pol needs to function?

Answer 26

RNA primers

Question 27

What are the 3 types of DNA?

Answer 27

Nuclear DNA - coding, Extragenic/junk DNA - noncoding, Mitochondrial DNA - rRNAs and tRNAs

Question 28

What are single copy genes?

Answer 28

most genes like CFTR, insulin, growth horomone

Question 29

What are multi gene families?

Answer 29

Arose through duplication of one gene

Question 30

Classic gene families:

Answer 30

overlapping functions

Question 31

Gene superfamilies:

Answer 31

non overlapping functions

Question 32

What is a cluster of genes called and what chromosomes are they on?

Answer 32

globin or globin chain found on chromosomes 11 and 16

Question 33

what causes a globin?

Answer 33

duplication and mutation

Question 34

What are microsatelites?

Answer 34

2-4 bp 10-30 repeats, rarely on coding genes and can cause disease

Question 35

What are minisatellites?

Answer 35

6-100 bp up to 1k repeats, telomeres

Question 36

What are satellites?

Answer 36

several hundred bp, clustered around centromeres

Question 37

What are tandem repeats? Length and what affects them?

Answer 37

Short-medium length sequences repeated in tandem. Affected by error during replication

Question 38

What is a TE or transposon?

Answer 38

A DNA sequence that can change its position within a genome

Question 39

How much of the genome are Transposable elements?

Answer 39

one third of the genome

Question 40

Who discovered transposable elements?

Answer 40

Barbara mclintock and earned nobel prize in 1983

Question 41

What are the two main types of transposable elements?

Answer 41

DNA transposons and retrotransposons - from RNA and use reverse transcriptase

Question 42

What are SINEs and what kind of transposons are they?

Answer 42

Short interspersed Nuclear elements that are Alu sequences ~300bp retrotransposons

Question 43

What is an SNP?

Answer 43

Single nucleotide polymorphism replacing, deleting or adding a nucleotide base

Question 44

What is a synonymous mutation?

Answer 44

Codon is changed but the amino acid is the same

Question 45

When is a missense mutation conservative and nonconservative?

Answer 45

Conservative if replaced with a similar AA nonconservative if replaced with a different AA

Question 46

What is a nonsense mutation?

Answer 46

Introduces a premature stop codon - truncated protein

Question 47

What does SNP splice site result in

Answer 47

Results in intron retention or exon skipping

Question 48

How many base pairs are indels usually?

Answer 48

1-3 bp

Question 49

What can indels cause?

Answer 49

frameshift, like Phe deletion

Question 50

What is the result when DNA pol slippage forms a loop in template? In new DNA?

Answer 50

Template - DNA deletion, new DNA - DNA insertion

Question 51

What diseases can Alu cause?

Answer 51

Insertion, coag factor IX deficiency, recombination- familial hypercholesterolemeia

Question 52

Structural polymorphisms?

Answer 52

Duplication, inversion, ind/el, translocation

Question 53

What are the 3 kinds of Loss of Function mutations?

Answer 53

Reduced activity, loss of protein, haploisufficiency

Question 54

How is loss of protein inherited? What does it mean?

Answer 54

Recessive. The presence of 1 functional copy = healthy

Question 55

What is haploinsufficiency? How is it inherited?

Answer 55

One copy is not enough to be healthy. Dominant inheritance

Question 56

What is a gain of function mutation? How is it inherited?

Answer 56

Increased gene expression or new function. Often dominantly inherited

Question 57

What is a Dominant-Negative mutation?

Answer 57

Heterozygote has loss of function as a mutation and interferes with the function of a normal gene product.

Question 58

What causes Chronic Myeloid Leukemia?

Answer 58

Reciprocal translocation from chromosome 22 to 9 - philadelphia chromosome

Question 59

What is Robertsonian translocation?

Answer 59

2 acrocentric chromosomes break and the q arms join.

Question 60

What issues does robertsonian translocation cause?

Answer 60

It causes issues at meiosis. Monosomies or down syndrome

Question 61

What is a gene?

Answer 61

The biological unit of heredity

Question 62

Alleles:

Answer 62

alternate forms of a particular gene.

Question 63

What is a trait? Example?

Answer 63

A variation of a character. Eye color is character and blue eyes are the trait

Question 64

What is a locus?

Answer 64

the location on a gene/chromosome

Question 65

What is a haplotype block?

Answer 65

Segments of DNA that do not undergo recombination.

Question 66

What is a hotspot?

Answer 66

Segements of DNA that are prone to recombination and allow the shuffling of haplotype blocks

Question 67

What is a haplotype?

Answer 67

A set of alles of different genes that are closely linked on one chromosome and are usually inherited as a unit.

Question 68

How is Duchene Muscular Dystrophy inherited?

Answer 68

X-linked recessive

Question 69

Where is the dystrophy gene for DMD?

Answer 69

Xp21

Question 70

Gower's sign is related to ?

Answer 70

DMD

Question 71

Acrocentric

Answer 71

No coding genes on little arms

Question 72

Submetacentric

Answer 72

Centromere is almost in the middle

Question 73

Metacentric

Answer 73

Centromere is in the middle can you can distinguish p and q arms