Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

ANAT 212 > BIO 202 > Flashcards

BIO 202 Flashcards

1
Q

Pattern of recessive traits recovery

A

1/4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Mono hybrid cross-ratio

A

3:1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

large sample increase or decrease variability

A

reduce

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

why use testcross

A

to see if theres a recessive trait

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

haploinsufficient

A

one functional copy of gene is enough to have normal function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What causes Cystic fibrosis and ratios of carrier parents

A
  • mutations in the CFTR gene
  • recessive
  • carriers parents = 1/4 of having a child with CF
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

dihybrid cross (explain and ratio)

A

ration: 9:3:3:1
- Rr/Yy
RY Ry rY Ry x RY Ry rY R
- must be on separate chromosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

can u get recombiannt progeny if gene A and B are on the same chromosome

A

no

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what does dihybrid testcross get you?

A

equal numbers of parental and recombinant progeny (1/4 , 1/4 parental, 1/4 1/4 recombiannt)
1:1:1:1 ratio

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Chi-square test formula and confidence level

A

X^2 = ∑(O-E)^2/E
p < 0.05 (95 confidence)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

when does crossover happen in meiosis

A

after DNA replication

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

could there be multiple crossovers in a single meiosis?

A

yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How do we calculate recombinant frequency

A

(#recombinants)/total progeny for every combination

Ex: 151 and 154 out of 2939 progeny have recombinant genotype
- (151+154)/2839 x100 = 10.7% = 10.7 m.u

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are SSLP

A

simple sequence lentgh polymorphism
- repetiitve DNA (short, simple DNA sequences)
- not associated with gene function)
- can determine crime, fingerprint

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

haplotype

A

Physical grouping of genomic variants (or polymorphisms) that tend to be inherited
together, as a single group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What gene is eliminated in CF patients.

A

loss of Phe508

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

People who lived up in teh mountain shad a special gene to them. what was it and what did it do

A

EPAS1 regulated the number of red blood cells that our bodies produce in response to the level of oxygen in our tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Relation between drugs and SNP?

A
  • Can see if there are certain SNP that are overrepresented
  • Can help determine if there are gene variants are present in future patients to assess possible future treatment or
    not (can be quite painful)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is haploinsufficiency?

A

you need 2 wild type copies for a protein function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is dominant negative and give an example

A

example: p-53 in cancer
- need 2 normal copies
- 1 mutant gene could allow thing to assemble but there would be loss of function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

difference between incomplete and partial dominance

A

incomplete: the heterozygous phenotype is a blend or mixture of the two homozygous phenotypes.
partial: shows a phenotype closer to one of the homozygous phenotypes. (will be closer to the dominant, not a perfect blend of both)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is co-dominance and example

A

blood type (AB is co)
both alleles as a phenotype are expressed/detected

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

define recessive lethal. Is it the same as synthetic?

A

NO!
recessive= having both alleles means death (cant happen in haploid organism because instant death)
- maintained as heterozygotes in our genome
- can be dominant or recessive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is auxotrophs. can we identify what genes they are missing

A

Organisms that lost the ability
to synthesize certain substances required for their growth
- yes, we can add random amino acids or nutrients to see what sprks their growth until we find it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what is conditional alleles give an example

A

phenotype depends on external factors
- Tyrosine kinase is an enzyme that is
responsible for black pigment, and is
active at lower temperatures
- Black pigment is produced as lower
temperatures
- higher temp = lethal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Define penetrance

A

The percentage of individuals with a given allele who exhibit the phenotype of that allele (even if you have the mutation, phenotype may be obvious or not)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

define expressivity

A

veryone is affected, but the degree to which a given allele is expressed at the
phenotypic level is different (ie: the intensity of the phenotype)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Define and give example of variable penetrance

A

Some develop the phenotype, some don’t
ex:
BRAC2 mutation is a predisposition to breast, ovarian, and pancreatic cancers, but not everyone with the mutation develops the mutation due to external factors:
- Environment
- Interacting genes
- Subtlety of mutant phenotype (difficult to diagnose)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

what is the complementation test?

A

for recessive mutation we can use this
- cross two pure bread mutants
- if it appears wild type: different genes
- if it appears mutant: same gene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

how can we see if mutation is on one or different genes?

A

complementation test with 3 mutations that make it look white
- %, & and $
- % and $ did not complement and resulted in white (so on the same gene)
- % and & = complement (bleu)
- $ and & = complement (bleu)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

what does a 9:7 ratio mean

A

that two different genes are on the sam pathway
- could also mean that there’s an interaction between regulatory gene and target gene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

what is recessive epistasis. what ratio results of this?

A

-mutation of one gene
affects the phenotype controlled by another
-
- 9:3:4 (9 = bleu flower, 4, white flower, 3 pink)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

what is a suppressor

A

Suppressor is a mutant allele of a gene that reverses the effects of an
original mutation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

what is a modifier?

A

Second mutation that changes the
degree of expression of a mutated gene (phenotype)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

define synthetic lethal

A

Mutations in two genes, each often has a weak mutant phenotype, resulting in lethality (when both are together)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

what is an indel

A

Insertion or deletion even of nucleotides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

what is a micosatellite

A

Repeats in nucleotides (with variation in the #repeats across individuals)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

what is a SNP

A

(single nucleotide polymorphisms): Nucleotide positions that vary in which nucleotide they are.
To be considered a SNP, the nucleotide position must be variable (“polymorphic”)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

what is a specific haplotype

A

Typically reflects a unique combination of variants that reside
near each other on a chromosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Name the 4 Emergent Population Genetic Level Forces (to cause evolutionary change

A
  1. mutation
  2. migration
  3. selection
  4. change (genetic drift)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

For a gene with 2 alleles what is the sum of frequencies?

A

For a gene with two alleles, A and a:
the frequency genotypes AA, Aa and aa can be denoted:
- fAA, fAa, faa
- The sum of fAA + fAa + faa = 1.0

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

what are two symbols for frequency of one allele? name some equations

A

p and q
p + q = 1
q = 1-p
P = f(AA) + 1/2 f(Aa)
AF = Homozygous + 1/2 Heterozygous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

define Ploidy

A

How many sets of chromosomes something has (n)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What can allele, genotype, haplotype frequencies be used for?

A

to characterize the genetic composition of
populations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

when does evolution occur?

A

when allele, genotype, and haplotype frequencies change

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Hardy-Weinberg theory helps us calculate what?

A

genotype frequencies in populations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

DNA fingerprinting and hardy weinberg?

A
  • Assuming Hardy-Weinberg principles and then calculating
    probability that the DNA match occurs simply by chance alone
  • google doc
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

When there is random mating what are the frequencies?

A

AA: p^2
Aa: pq
aa: q^2
p^2 + 2pq + q^2 = 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

what does identical by descent mean?

A

Inbreeding increases the probability that two alleles at a locus will be copies of an allele present in an ancestor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

what is inbreeding coefficient and the equations that come with it?

A

F quantifies the overall probability that the two alleles inherited by a given individual will be
identical by descent
1. F = (1/2)^n
2. f the parent A is also inbred:
F = (1/2)^n *(1+F_A)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

What If There is More than One Common Ancestor (Full Sibling Mating)?

A

F = (1/2)^n + (1/2)^m

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

what do you observe in population that switches over to inbreeding from random mating

A

more homozygous, less heterozygous
- Inbreeding has no effect on allelic frequencies, but does affect genotype frequencies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

what is inbred depression

A

Inbreeding depression (reduction in the viability of inbred individuals) occurs because most deleterious (harmful)
conditions require two copies of the mutation to be expressed
- can lead to smaller population, lower reprduction and higher mortality

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

describe mutations

A
  • event rates are relatively low
  • doesn’t cause much change in allele frequencies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

describe genetic drift

A
  • Losing alleles due to chance
  • Individual populations lose genetic diversity and
    populations diverge from one another
  • normally occurs in small populations
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

describe migration

A
  • Introduces new genes into the gene pool from somewhere else
  • can be uni (like mutations introduce alleles into a population) or bidirectional (keeps population from diverging from one another)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

what is bottleneck event

A

dont expect the same porptions as previous large populations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Determine the Average Population Fitness equation

A

Wavg = f(AA)w(AA) + f(Aa)w(Aa) + f(aa)*w(aa)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

Determine the Frequency of the Genotype After Selection

A

w(AA)*f(AA)/Wavg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

Determine the Frequency of the Alelle After Selection

A

q = f(aa) + 1/2*f(Aa)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

Name the twp types of selection possible.

A
  • Directional selection: Where there’s a real advantage to one form that carries as homozygous for the alleles in question
  • Balancing selection can also occur in nature: Maintains variability of alleles with heterozygous advantage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

what is the ration for GENOTYPE of a heterozygous x heterozygous cross?

A

1:2:1 (YY, Yy, yy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

Why is it that the recessive and deleterious diseases haven’t been driven out already by natural selection?

A

Mutation (consistently introducing these new alleles)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

what is a selective sweep

A
  • reduces diversity
  • specific allele (a variant form of a gene) increases rapidly in frequency in a population due to positive natural selection
  • leaves trace of past events
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

Difference between simple and complex traits

A

simple: discrete expression (white/purple, long/short)
- Population variation controlled by one/two genes
complex: many genes and many environmental effects influence trait expression and variation (ex: population variation) (bell-shaped distribution= height)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

what are the two types of complex traits

A
  1. continuous
    - Body size, running speed
    - All individuals present the trait in some way
  2. threshold
    - Increasing genetic/environmental liability to a certain
    threshold (and then the individuals present the trait)
    - cancers, heart disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

What is phenotypic variance of a trait

A

How much is due to differences in the environment that individuals experience and how much is due to genetic differences among individuals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

Equation for broad sense heritability and meaning of it being high or low.

A

H^2 = Vg/Vx
Vx= Vg+Ve
low: no correlation
high: traiy affected by both genes and envirnment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

what is GWAS

A
  • Using molecular markers to infer the presence and affects of genes that influence genetic variance
  • Using association between SNPs and disease to
    detect genes that influence complex diseases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

describe QLT mapping

A
  • Co-segregation (co-inheritance) of phenotypes and marker alleles (usually SNPs)
  • locate the region of the genome where a gene with influence on the phenotype resides
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

define Autopolyploids

A

An individual that has multiple chromosome sets originating from within one species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

define Allopolyploids

A

An individual that has multiple chromosome sets originating from two or more different species (ie: hybrids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

define aneuploidy

A

Not a whole full set (extra/missing individual chromosomes) (not a multiple of n)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

how dow e calculate P(euploid)

A

P(euploid)= (0.5) ^(n-1) (n being how many chromosome sets we have)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

are triploids sterile? how can they be made

A

yes, cross a 4n (forms diploid gamete = 2n) with a 2n (forms haploid gamete 1n) 1n+2n = 3n

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

how do we form tetraploid

A

used colchicine to disrupt microtubules to keep the replicated chromosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

what is dispermy

A

2 chromosome from sperm and 1 from egg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

example of allopolyploid

A
  • Crossing a cabbage (2n) with a radish (2n)
  • Somewhere along the line, there was spontaneous doubling of the chromosomes (4n)
  • results in amphidiploid (a hybrid with four pairs of chromosomes, two different kinds)
  • if amphidiploid mixed back with parent it makes sterile children cannot mix again
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

name 5 types of trisomies

A
  • XXX (normal)
  • XXY (Klinefelter syndrome (still normal, just different characteristics)
  • Trisomy 21: Down syndrome
  • Trisomy 13,18: Non-viable, die in infancy
  • All others: Non-viable, die in utero
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

name an example of viable monosomy and what it is

A

XO (instead of XY or XX) : Turner syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

what is the gene dosage hypothesis

A

refers to the idea that the amount of genetic material (the “dosage”) present in an organism directly influences its traits and characteristics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

what is non-disjunction and when can it occur

A
  • Failure of chromosomes to properly segregate during anaphase
  • If occurs in meiosis I, results in 100% aneuploid gametes
  • If occurs in meiosis II, results in only 50% aneuploid
    gametes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

what is Cri-du-Chat Syndrome

A

Part of chromosome #5 is missing (chromosomal deletion of 17 genes) resulting in a diseased phenotype
this means:
- 1 or more of these 17 genes is required for development
- None of the 17 genes are haplosufficient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

how can chromosomal deletion occur and give an example.

A

intermediate segment is cut out and lost
1. incorrect breakage and rejoining
2. incorrect crossover between repetitive DNA during meiosis
ex: Williams Syndrome Deletion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q

explain Williams Syndrome Deletion

A

1.5-Mb deletion on one homolog of chromosome 7, specifically at band 7q11.23
1. two repeptivtive sequences will form an unequal crossover
- leads to 1 deletion and 1 duplicated chromosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
86
Q

how can duplications occur (2)

A
  • results from breakage and rejoining but rejoining with incorrect chromosome
  • results from crossing over between repetitive DNA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
87
Q

name 2 ways chromosomal Rearrangements: Inversions can occur and the difference between including or not the centromere

A
  • results from breakage, flipping and misrepair
  • Results from the misalignment of homologous
  • can be paracentric (doesn’t include the centromere) or
    pericentric (does include the centromere) inversions.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
88
Q

name 3 different breakpoints ways/conseuqneces

A
  1. Breakpoints between genes: No genes are disrupted
  2. one breakpoint point within genes: Split gene is
    disrupted
  3. Breakpoints within two genes, resulting in fused genes (eg: A and D are now fused): Gene fusion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
89
Q

when does combination occur

A

during meosis I (crossing over of homologous chromosomes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
90
Q

consequences (germline) of inversion

A
  • during meiosis in order to line up properly with its homolog, part of the chromosome has to loop out (formation of an inversion loop)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
91
Q

what happens to crossing over with paracentric inversion

A
  • eterozygote, the result is a dicentric chromosome (a chromosome connected by two centromeres)
  • can lead to deletions: The chromosomes try to segregate, but the dicentric chromosome breaks randomly and a chromatid (that wasn’t attached) is lost
    SUMMARY:
    Crossing over in a paracentric inversion heterozygote —>
    Dicentric chromosome —> Breakage —> Loss of acentric fragment –> dicentric bridge breaks randomly and products with major deletions
  • acentric : no centrosome
  • dicentric: has it
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
92
Q

Clinical Consequences In Chromosomal Inversion Adult

A
  • decreased fertility
  • when germ cells undergo meiosis (as shown above), only 2/4 gamete are viable (the non-recombinant products)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
93
Q

Chromosomal Translocations explanation and consequences

A
  • no gain/loss of genetic material
  • can occur due to breakage or disrepair or cross over
  • as long as break didn’t disrupt any haploinsufficient
    genes, not many consequences somatically
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
94
Q

name two segregation patterns in a reciprocal-translocation heterozygote

A
  1. Adjacent segregation pattern: N1 and T2 migrate together (bad both incomplete)
  2. Alternate segregation pattern: N1 and N2 migrate together (both good one normal one translocation making them viable)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
95
Q

Robertsonian Translocations what is it

A
  • involve any of the acrocentric (one chromosomal arm is much shorter than the other due to positioning of the centromere)
  • chromosomes: 13, 14, 15, 21, 22
  • long ones bind = survive
  • long and short bind = survive
  • short and short = get lost because not haplosufficient
96
Q

explain Grape-Colour Genetics in relation with transposable element insertions are associated with changes in grape colour

A
  • insert LTR retroelement = LOF of green pigment because insertion in regulatory region
  • recombination LTR: leaving only a small insertion behind
  • This insertion is enough to not allow pigment to be expressed at a normal level (resulting in red colour, an intermediate)
97
Q

what traits can we map on chromosome 9

A
  • Colour
  • Shrunken
  • Bronze
  • Waxy
    chromosome 9; recognizable with its distinct knob at the end
98
Q

difference between embryo and endosperm

A
  • Endosperm (made up of many cells); where we see the traits; fertilized by sperm cell (n) and central cell (2n)
  • Embryo; what’s growing inside; fertilized by sperm cell (n) and egg cell (n)
99
Q

explain hypothesis where C1 allele is lost in some cells of the developing endosperm, no longer blocks C function (corn)

A

loss of C1 alleles is caused by chromosome breakage
- done on chromosome 9

100
Q

are breakage random? do they always happen at the same place? what is needed? (corn)

A

no, they always happen at the breakpoint (Ds = dissociation locus)
- also, Ac locus is also needed on other chromosome

101
Q

what does it mean for alleles if breakage occurs or not (at breakpoint) (corn)

A
  • break doesn’t occur, wild type alleles are present
  • breakage occurs, you’ve lost the wild type alleles and recovers recessive mutant phenotype
102
Q

are Ds and Ac mobile? to the same degree?

A

Yes both are mobile.
NO:
1. Ds requires Ac to “jump out” (ie: transpose); Non- autonomous
2. Ac jumps out on its own; autonomous (encodes it’s own transposition machinery)

103
Q

what does different spots in kernel mean about when they get activated

A

earlier activation results in a larger spot, while later activation results in a smaller spot.

104
Q

name the two classes of transposable elements

A
  • Class 1: Retrotransposons (eukaryotes)
  • Class 2: DNA transposons (prokaryotes and eukaryotes)
105
Q

which class does Ac and Ds belong to of transposable elements

A

DNA transposons
- each has a transposes version specific for its own family

106
Q

explain process of class 2 tranposons getting cleaved and by who (corn)

A

-Ac and Ds have enzyme in the middle of them that catalyses reaction
- two end of inverted repeats of each other
- Transposase binds to repeats, cleavage event, breakage releases intervening sequence
- insertion into target protein

107
Q

explain how class 2 retrotransposons occur, form and give examples

A
  • similar to retrovirus
  • Have LTRs
  • Have pol gene; replicates viral genome
  • Have env gene; viral envelope needed for the cell to produce more virus
  • Have gag gene; protein antigen on viral coat
    TE: have everything except env
  • EX: LINE (long interspersed element) is a retrotransposon found in the human genome or SINE
108
Q

Can retrotransposon move through an RNA intermediate? if yes, how?

A

yes
- this transposition is mediated by reverse transcriptase (encoded by pol gene) NOT THE TRANSPOSASE
- copy-paste mechanism
- Makes a double stranded transposon genome that goes back into the nucleus and with LTRs can insert into the genome

109
Q

where are TE located

A
  • in introns or intergenic regions
  • low risk of potential harmful effects because its in between cells (because it isn’t in ORF which would be lethal = selection for fitness and viability)
110
Q

are genomes with more TE bigger or smaller why.

A

bigger: larger the genome, the larger the percentage of transposable elements

111
Q

what happens if TE is introduced in exons instead of introns

A

many disease mutations :
- could disrupt slipcing:
insertion of an AluYa5 element in a patient with Dent disease (a rare genetic kidney disorder) interrupts an exonic splicing enhancer, resulting in skipping of an exon 11 producing a stop codon in exon 12

112
Q

how are TE associated with cancers

A
  • their mobility can destabilization of the genome causing tumour formations
  • this is why they’re highly regulated and cells have mechanism to repress them
113
Q

is TE mobility always bad? (moths)

A

NO! can be an positive adaptive change:
- Dark pigmentation is caused by TE insertion into a gene in moths
- this is beneficial for them

114
Q

discuss drosophila P-elements

A
  • class 2
    p-elemnts are TE
  • discovered mating lab and wild caught flies
  • lab female x wild male
  • F1 could not produce any offspring due to mutations and non-disjunction
    RECIPROCAL CROSS:
  • lab male x female will
  • they were fine suggest that there’s a mechanism that blocks transposon mobility
  • key is the female germ line
  • p-element from male moves and infers female germline
  • this is silences if the female is wild-caught
115
Q

how many spontaneous mutations are due to TE of LINE or SINE

A

1/600

116
Q

explain TE in c.elegans and work and discuss experiment they did (somatic vs germline)

A
  • C elegans also have TE
  • Tc1 element: An autonomous DNA transposon (class 2
  • Tc1 elements transpose in somatic cells but not
    germline cells meaning the germline contains some sort of silencing machine that represses tc1 mobility
117
Q

how can we find TE

A

if we knock out a gene involved in repressing TE mobility, then TE will be able to move
- Figuring out which gene is mutate in such a train will identify a part of the cellular machine that represses TE
mobility

118
Q

discuss a time where TE mobility was good. (not moths)

A

c elengans for twitching
- Tc1 insertion in the unc-22 gene (disrupting it)
- If the Tc1 mobilizes/jumps; the worm can move smoothly

119
Q

what type of genes are involved in blocking Tc1 mobility.

A

RNAi silencing

120
Q

describe RNAi silencing pathway

A
  • derived from dsRNA precursors
  • Once fully processed, miRNAs bind to RISC complex
  • RISC complex has a single nucleotide (miRNA) strand that targets RISC destruction complex to the transcript it is programmed to silence
  • cause degradation via deadenylation or block translation
  • this processes also includes dicer which does the cleaving
121
Q

difference between endogenous and foreign gene.

A
  • miRNA: endogenous gene
  • siRNA: foreign gene (transgene, virus, TE)
122
Q

describe the process of dicer/RISC complex (end part)

A
  • Tc inserted normally in the genome (not next to any cellular
    genes), the TIRs are not transcribed (only the transposase gene)
  • Tc directly adjacent to a cellular gene and the cellular gene gets
    transcribed, the TE and it’s TIR’s are transcribed
  • complementary
    stem loop forms between the TIR’s of the mRNA transcript
  • Dicer recognized the stem loop, chops it up and programs it into the RISC complex
  • RISC complex can now find any transposase transcript in the genome and target it for degradation
123
Q

what are piRNA. explain mechanism.

A
  • repress transposon mobility in germ line of Drosophila
  • blocks the transcripts coming from the TE
  • are NOT derived from dsRNA precursors
  • Like siRNAs, piRNAs are short single-stranded RNAs that interact with a protein complex that destroys complementary target mRNAs
124
Q

what does pi-cluster mean

A
  • Pi-cluster: RNAs that participate in destruction complex are made here (the programmed transcripts)
125
Q

explain what piwi-argonaute is and what mechanism it belongs to

A
  • piRNA
  • Piwi-Argonaute is programmed with sequence information and destroys mRNAs
126
Q

explain Three Different Scenarios for TEs Mobility (active/inactice area?)

A
  1. TE is inserted into an inactive area; not transcribed in the first place
  2. inserted into active: gets transcribed, BUT is present in pi-cluster so gets degrades by Piwi argonauts
  3. inserted into active: gets transcribed, NOT yet inserted into pi- cluster can be mobile
127
Q

explain piRNA in male/female lab/wild type

A
  • piRNAs are present in P-strain (wild caught) but not M strain (lab strain)
    P-female x M-male: F1 are fertile
  • P-female chromosome has P-elements in her pi cluster (piRNAs in her eggs that block transposition in the germline of the embryo)
128
Q

what gene I sable to repress TE activity. explain mechanism in drosophila

A

p53 (plays a role in repressing TE mobility)
- TAHRE is the retrotransposon in drosophila
- little TE transcripts when p53 is rescued (due to p53’s silencing)
- a lot of TE transcript when p53 is mutant
- Human p53 corrects disregulated transposon activity in p53- flies, but p53 variants commonly seen in cancer patients do not
- cancer alleles don’t block TE mobility

129
Q

where do most mutations occur

A

somatic cells

130
Q

can mutations be inherited

A
  • mutations that occur in the formation of gametes can be inherited
  • In 50% of the offspring, they carry the mutation
131
Q

describe 3 categories of mutations

A
  • Chromosomal mutations: Gain or loss of all or part of a chromosome (deletion; duplication; inversion;
    translocation)
  • Insertional mutations: Insertion of large regions of DNA (TEs)
  • Point mutations: Changes in a single nucleotide or addition/deletion of one or more nucleotides (as long as
    they are small)
132
Q

2 groups of point mutations

A
  1. Base substitutions
    - Transition: Purine—> Purine; Pyrimidine —> Pyrimidine
    - Transversion: Pyrimidine —> Purine; Purine—> Pyrimidine
  2. Base additions and deletions (indels)
133
Q

The Consequences of Point Mutations in ORF

A
  1. Synonymous Mutations
    - Silent mutations (sequence change
    but not the amino acid it encodes)
  2. Non-synonymous Mutations
    - Missense mutations (sequence change of a codon to one that codes for a different amino acid)
    - Can be conservative (amino acid similar) or non-conservative (chemically different amino acid)
  3. Nonsense Mutations
    - Change the sequence of a codon to one that stops translation (stop codon; UAA; UGA; UAG) - Effect depends on distance from 3’ end of the ORF
    - Can trigger nonsense-mediated decay (NMD) which degrades the mRNA
  4. Frameshift mutations
    - Caused by an insertion or deletion
    - Changes the reading frame for all codons downstream of the mutation
134
Q

discuss Point Mutations Different Effects; Depending on Their Location and Type of Mutation

A
  1. LOF (partially or completely lost)
    - Hypomorphic: Weak/partial —> retains some function or produced at reduced level
    - Null: Protein is non-functional or not produced
    ex: p53 mutations eliminate function
  2. GOF: (gene function increased)
    - Hypermorphic: protein is hyperactive
    - Ectopic: More protein is made in wrong time/place - Neomorphic: Protein gains new function
    ex: mutation in ras gene make them constitutively active
135
Q

discuss example of Sequences in Non-Coding Regions can be Important for Gene Function

A

Mutations in non-coding regions can disrupt:
- Transcription - Splicing
- Stability
- Translation
- function
- if mutation in promoters or enhance = compromises ability of the gene to be expresses

136
Q

why can point mutation affect splicing

A

Can make new splice sites or eliminate existing splice sites

137
Q

explain how Same Mutation and Different Prognoses

A
  • can have additional mutation correlated, worsening the situation
  • PBRM1 gene has BAP1 which creates stop codon = terrible
138
Q

difference between northern and western blots

A
  • Northern blots look for RNA
  • Western blots are looking at protein
139
Q

what is Electrophoretic mobility and what does it depend upon

A
  • position on a gel
  • reflect size, and band intensity reflects the amount present
140
Q

can mutations be Spontaneous or Induced

A

both:
- Spontaneous: Occur naturally, arise in all cells (due to errors in DNA replication and chemical changes in the DNA)
- Induced: Caused by exposure to ionizing radiation, mutagenic chemicals, etc, which increase the rate at which mutations occur

141
Q

how many mutations do we carry in our DNA

A

100-200 new mutations in our DNA

142
Q

discuss errors in base pairing and give example

A
  • no prrmfreadin : mismatch
  • relevant during replication because conversion between tautomers happen all the time
  • BUT if polymeriase adds complementary nucleotides, its bad
    EX: If Guanine is in its enol form, DNA Pol. adds a T instead of a C (because that is the complementary pairing to the enol guanine)
143
Q

what is a tautomer

A
  • isomers that differ in the positions of their atoms and in the bonds between the forms; the forms are in equilibrium
144
Q

difference between incorporate terror and replicated error

A
  • Incorporated error: can still be repaired (G reverts to its normal form, and mis-match it recognized and repaired)
  • Replicated error: permanent
145
Q

how do spontaneous mutation occur

A
  • Strand slippage during DNA replication leads to indels
    2 ways of insertions/deletion:
  • Newly synthesized strand looping out causes
    insertions
  • Template strand looping out causes deletions
146
Q

give an example of slippage

A
  • Trinucleotide repeat disorders (expansion of
    of repeated sequence) (prone to slippage)
  • If they loop out; they get duplicated or deleted
  • high # of repeats (n) = high slippage = more expansion (more n)
147
Q

explain fragile x syndrome

A
  • Trinucleotide repeat expansion in non-coding region of the FMR1 gene
  • Normal: <45 repeats of CGG
  • > 200 repeats = methylation occurs and gene no longer transcribed
148
Q

explain Huntington disease

A
  • Trinucleotide repeat expansion in coding region of the HTT gene
  • > 40 repeats the mutation is severe
  • genetic anticipation; gets more severe with each new generation)
  • More expanded repeats means a more severe allele
149
Q

3 things that can cause spontaneous chemical changes to DNA

A
  1. Deamination of cytosine: Structure becomes identical to uracil (and thus binds to A)
  2. Depurination: Nucleotide loses its nitrogenous base and left with apurinic site (there is no base pairing
    possible)
  3. Oxidative damage: Causes by byproducts generated by mitochondria
150
Q

explain induced mutations. explain the 3 mechanism

A
  • Mutagens can induce misfiring or damage/non-recognition
    1. Replace a base in the DNA (base analogs get incorporated instead; look like a DNA base)
    2. Alter a base so that is mispairs with another base
    3. Damage a base so that it can no longer base pair with any base
151
Q

what does UV light do

A
  • Base damage
  • UVB light can induce covalent interactions between adjacent pyrimidines
  • If not repairs, this can block DNA replication
152
Q

what does radiation do

A

Cause breaks in the DNA; make the DNA very vulnerable to insertions/deletions/inversions/etc.

153
Q

explain Ames test

A
  • test if chemical causes mutations
  • take a bacteria that is unable to grow withtou histidine (auxotroph)
  • feed it chemicals until you see that one makes it grow again
  • that chemical caused a mutation in the genome of the bacteria a
154
Q

problems with Ames test

A
  • in humans, some chemicals can only be activated when they are metabolised
  • originally may not do anything unless they are metabolized
155
Q

what is the better version of the Ames test after discussing the problem with it

A
  • add liver enzymes to test chemicals that might become mutagenic only when metabolized
    2 strains used:
  • Strain 1 = His-transition mutant (point mutation)
  • Strain 2 = His-frameshift mutant
  • we see that strain 1 has more revertant rate = can infer that the mutagens causes point mutations
156
Q

explain how we can predict is and ORF corresponds to a real gene

A
  • look fro ORF (can codes transcribe without hitting stop codon too early)
  • is ORF conserved? (means important sequence)
  • look for cDNA: mRNA and the RT makes cDNA
  • compare cDNA sequence to the predicted ORF
  • If cDNA sequence matches the predicted ORF = means that at some point, the gene was turned on and its mRNA was made in the cell
157
Q

what is EST

A

Expressed Sequence Tag is a cDNA that has - not been completely sequences

158
Q

how can use codon bias to check if and ORD was part of a real gene

A
  • this codon preference reflect relative tRNA abundance and can be a signature of an ORF that’s part of a real gene
  • If a predicted gene uses a common codon; hint that it might be part of a real gene
159
Q

explain difference between comparing within organism , individuals of same species, between organism.

A
  • within an organism: identify gene families and gene duplications
  • individuals of the same species: identify differences associated with phenotypes or disease
  • between organisms: different types of genes and their arrangement in the genome and to infer information about genome structure and evolutionary processes
160
Q

does mutations aossicated with disease affect coding or non coding regions of genes

A

coding

161
Q

discuss further comparing Sequences Within a Species

A
  • reveals families and related genes
  • Related genes within an organism that encode proteins of similar amino acid sequence
  • Can contain 2 to >100 members (called PARALOGS)—> In the same genome (beta tubulin vs. alpha tubulin)
  • Members can be functionally redundant or have independent functions
  • Can arise through gene duplication during evolution
162
Q

how do we identify diseased genes. do we take the whole genome?

A

no, we look at exome
- contains all the protein-coding genes (non-coding region not included)
- more cost efficient this way

163
Q

what is synteny. give example

A

The conserved order of genes between the two genomes
- 99% of mouse genes have a homolog in the human genome
- Overall genome organization, including the relative order of genes and non-coding regions, is also highly
conserved

164
Q

difference between orthologs and paralogs

A
  • Orthologs: Homologous genes at the same genetic locus in different species, evolutionary inherited from a common ancestor (frog A, human A, mouse A)
  • Paralogs: Homologous genes at different loci in the same species, having arisen from gene duplication (mouse A and mouse B)
165
Q

what is uni-parental disomy. discuss consequences

A

getting 2 copies of chromosome form 1 parent
- Non-disjunction; two copies in one gamete; gives rise to a trisomic zygote
- Randomly, one of the extra chromosomes get lost (trisomy rescue) —> reversion to disomic

166
Q

why does every cell in our body have the same DNA sequence

A
  • they all get made by blastocyst which differentiate into different cells of our body (muscle, neurons..)
  • What makes each cell type unique is largely determined by the expression of specific subsets of tissue-specific genes (mostly controlled at the level of transcription)
167
Q

discuss gene expression in prokaryotes

A
  • dna is nacked (not wrapped in histones)
  • transcription initiation is a main regulator process
  • Many prokaryotic metabolic genes involved in the same process (eg: same metabolic pathway) are organized into operons
168
Q

what are operons

A

one transcript unit coding for multiple proteins under a single promoter

169
Q

name 2 promoter sequences in prokaryotic genes + start codon

A
  • TTGACAT: -35
  • TATAAT: -10
    • ATG start codon (Met)
  • Upstream is +1 nucleotide (first one incorporated into mRNA), transcription start site
  • Everything between +1 and ATG: 5’ UTR
  • Promoter: Where regulation takes place
170
Q

Discuss RNA polymerase in prokaryotes

A
  • RNA polymerase binds to -35 and -10 promoting paper position of holoenzyme (mili-subunit)
  • RNA polymerase easily binds the promoter; default state of genes is “ON” (a bit…)
  • Sigma factor finds sequences relatively easily since no other proteins associate with the DNA
171
Q

DNA binding proteins can activate or repress gene when? where? what?

A
  • depending on where they bind
  • operator: binding sites for suppressor genes
  • activating bringing site = positive regulation
172
Q

describe allosteric regulations and what they bind to in activator or repressors.

A
  • Allosteric site in the protein binds to an effector;
    ACTIVATOR:
  • no effector = gene off
  • effector = gene on
    REPRESSOR
  • no effector = gene off
  • effector geen on
  • Effectors: Sugars, amino acids, small chemicals, sometimes other proteins
  • Effector is called an “inducer” if its presence leads to increased expression; effector can turn on an activator or also turn off a repressor
173
Q

discuss the enzymes and regulatory components of la operon

A
  • Bacteria want to metabolism lactose into glucose
    Enzymes:
  • LacY (permeate) —> Pumps lactose in
  • LacZ (B-gal) —> Breaks it down
    Regulatory components:
  • Repressor protein (LacI) —> Not part of operon - LacO (operator)
  • LacP (promoter)
174
Q

describe lac operon and how it works

A
  • inducible: lactose will turn on expression of lac operon
  • repressor: protein block RNA polymerase
  • lactose binds the repressors allosteric site to allow RNA polymerase to transcribe
175
Q

how can we uncover the regulatory mechanism of lac operon using chemical in the lab?

A
  • used mutagenesis: treat E.coli with chemical mutagens
  • measure B-Gal and/or Lac permease activity in presence and absence of a synthetic inducer (IPTG) —> Looks like lactose
  • Selected mutant strains where one or both of these activities was altered
176
Q

describe 3 classes of Jacob and Monod’s Lac Mutants (synthetic lactose experiment)

A
  1. structural gene mutations (affect function of only one gene cannot function)
  2. uninducile (cannot make LacY or LacZ in presence of IPTG = failure to activate any of them)
  3. constitutive mutants (makes both LacY or LacZ in presence of IPTG= cannot turn them off)
177
Q

explain partial diploids in IPTG experiment replacing lactose

A
  • “partial diploid” bacteria containing a plasmid with an extra copy of the lac operon (diploid lac operon)
  • second copy of lac operon is often carried on a plasmid
  • test for domincane/ recessiveness
  • helps us determine cis/trans:
    Cis: Mutation only affect transcription of genes on same DNA molecule (often a regulatory element)
  • Trans: Mutation can also affect transcription of genes on the other DNA molecule (on other copy)
178
Q

explain lac operon regulations (p-mutations) and cis/trans

A

p-mutation results in failure to activate gene expression ( indelibility of both B-Gal and
Permease)
- P+Z+Y+/F’P-Z-Y-: original has inducible promoter, but mutant makes it loose that ability (P-) = cannot act in trans
- P- acts in cis
-
P-Z+Y+/F’P+Z-Y-: original had P- but promoter was able to restore its ability making It act in cis
-

179
Q

DISCUSS LAC OPERON REGULATIONS: O MUTATIONS (operator)

A

O- = Oc (constitutive): Both B-Gal and Permease
are constitutively active
- repressor portion can’t bind (can’t be turned off)
- Oc/Z-/Y- doesn’t affect regulation of O+Z+Y+; inducible
- o mutations only works in cis WTF WHY

180
Q

discuss Lac Operon Regulation: I- Mutations

A
  • similar to O (always on)
  • Won’t make functional repressor protein; genes expressed even in absence of lactose
  • +/Z-Y- and F’I-/Z+Y: Inducible: Repressor from I+ will be made and will bind to the operator on I-/Z+/Y+
  • I doesn’t have to be on the same DNA molecule, can act in trans (a diffusible molecule)
181
Q

how to solve questions about lac operon mutations…

A
  • First check Z and Y
  • Second check promoter
  • Third check O
  • Fourth check I
182
Q

discuss Lac Operon Regulation: I^S Mutations “Super-Repressor”

A
  • always reposed no matter what (even if wild type I is present)
  • Mutating the allosteric site of LacI, repressor can’t bind lactose to be turned off
  • I^S is different from I-; it cannot be complemented by I+ (ie: it’s dominant to I+)
183
Q

What would be the phenotype for the following lac operon partial diploid?
I+ P+ O+ Z- Y+/F’I+ P- Oc Z+ Y-

A
  • Z is uninducible (Z- and P-)
  • Y is inducible (left chromosome is completely functional for Y+
184
Q

explain when lac operon is under positive regulation (CAP and cAMP)

A

bacteria likes glucose > lactose (doesn’t ned to break it down less wasteful)
- glucose regulates cAMP levels (high glucose means cAMP inhibited)
- cAMP: allosteric regulates of CAP (coded by crp gene and Called Catabolite activator protein)
- no cAMP= no DNA binding
- CAP-cAMP binds promoter just upstream of RNA Pol.
- Facilitates RNA Pol. binding to the promoter to increase transcription

185
Q

explain all 3 scenarios of lac operator regulation (glucose absent, lactose present….)

A
  1. Glucose present; no lactose (low cAMP inactive CAP = no activation)
    - repression = no lac mRNA produced
  2. Glucose present; lactose present
    -glucose present = (low cAMP inactive CAP = no activation)
    - HOWEVER no repression because lactose is present
    - Very little lac mRNA produced
  3. Glucose absent; lactose present
    - high cAMP active CAP = activation
    - no repression
    - Abundant lac mRNA
186
Q

what is the default state of transcription for bacterias and eukaryote

A
  • Default bacterial state is on (a bit)
  • Default eukaryotic state is off (completely)
  • Bacterial have simple group of proteins; repressor, activator, CAP
  • Eukaryotes have many components to transcription
187
Q

whats an enhanceosome

A

Sum of proteins + enhancers + folding; allows enhancer to be close to promoter

188
Q

discus transcription Initiation (cis-acting or trans-acting proteins? DNA sequence?

A
  1. Cis-acting DNA sequences
    - Core promoter
    - Promoter-proximal elements - Enhancers/silencers
  2. Trans-acting Proteins
    - General transcription factors
    - Common transcription factors
    - Cell/tissue-specific transcription factors
    - Transcription co-factors; cofactors have no DNA binding domains and thus depend on those of a transcription factor
189
Q

does transcription need enhancer sequences. describe these sequences

A

yes
- Distance-independent cis-acting DNA sequences
- can be far or close or in introns
- Bind DNA in a sequence-specific manner through DNA-binding domain

190
Q

what are some influences of transcription

A
  • Interacting with transcription apparatus (directly or indirectly)
  • Influence chromatin structure opening/closing (directly or indirectly
191
Q

what mutation is associated with OPN1-LW gene - explain skewed / 50/50

A

red-green blindness (check notes)

192
Q

what x -linked disease is only seen in heterozygous female

A

rett syndrome (only mut/+ females are viable)

193
Q

what is methylation of DMNT associated with

A

occurs on cytosine of CpG

194
Q

is dna methylation inheritable

A

yes

195
Q

what do DMNT have high affinity for

A

hemimethylated sites (only one is methyl) goes in and fixes it

196
Q

describe IGf2 mutations

A
  • dominant
  • heterozygous things born small, only if got mutation from father
197
Q

describe silences alleles and how it occurs

A
  • if you get silenced allele it doesn’t matter if its mutated or not
  • occurs through methylation to the “imprinted” or silenced gene
198
Q

whats an example of ICR (imprinting control region)

A

-CpG island

199
Q

describe IRC methylation in father mother

A

father: only sex-specififc methylation of ICR: methylation prevents CTCF binding: methylation of H19 and enhancer turns on Igf2 gene
mother: non-methylation: allows CTCF to bind (acts as a insulator) regulates H19 and does NOT turn on IGf2

200
Q

what is mono-allelic inheritance

A
  • as if there’s only one copy in the cell
  • silneced/mutant gene is mutant: nothing happens
  • normal one gets mutated: does matter
201
Q

mechanic leading to a disorder associated with an imprinted gene

A
  1. mutations affecting non-imprinted gene
  2. epimuttaions ( histone tail or DNA methylation)
  3. uniparental disomy ( non-disjunction , robersonian carrier..)
202
Q

mitochondrial diseases diff in genes

A

987: come from mendelian fashion
13: come from the maternal/cytoplasmic fashion

203
Q

what is neurospora

A

follows rules
poky: motherly inherited
ad gene: follows mendelian and is inherited independently to the mother one

204
Q

explain heteroplasty in mtDNA mutations

A
  • mtDNA is more likely to have mutations because they have more frequent DNA replication + no DNA repair mechanism
  • spontaneous mtDNA leads to 2 distinct mt populations within a single cell
205
Q

what happens if your mom is heteroplasmic mutated. like what does it mean for child

A
  • means that mother has both affectes and unaffected mitochondria
  • has a possibility of being normal due to random segregation
206
Q

what were Heidelberg screens used for

A
  • mutations disrupting early embryonic pattern
  • did forwards genetics to see what genes were involved for organizing drosophila
207
Q

what is the order of the genes (5 groups): cascade of TF that regulate drosophila

A
  1. Egg-polarity event (maternally loaded)
  2. gap genes
  3. pair-rule gene
  4. segment Polarity gene
  5. homeotic genes
208
Q

what is bicoid and what does it do

A
  • lack anterior segments
  • code for anterior things like head
  • diffuse towards posterior to create a concentration gradient providing info about distances relative to anterior position
  • hunchback is in the anterior and nanos will inhibits translation of hunchback
209
Q

name eve proteins and what they do

A
  • giant (expressed in front of gene)
  • kruppel (expressed in back)
  • both act as repressors
  • hunchback proteins + bicoid : high levels act as activator (middle of protein)
210
Q

discuss segment polarity and what it encodes for

A
  • encode components of two cell-cell signalling pathways : hedgehog and wingless
211
Q

give example of homeotic mutations

A
  • Ubx: second third and set of wings in place of halters
  • Antp: legs instead of antenna
212
Q

humoral vs cellular immunity

A
  • humo: production and secretions of B cells
  • production of T cells (bind to antigen found on surface of their own body)
213
Q

adaptive vs innate immunity

A
  • adapt:antigen specific defense (T and B cells)
  • Innate: quicker and non-specific (macrophages and neutrophils)
214
Q

vaccines

A

use RNA vaccines using host cell to produce antigens which is must faster

215
Q

light chains types and segments

A

kappa and lambda (cant be kappa/lamda)
- segments V, J and C
- binds to antigen

216
Q

heavy chains types and segments

A

alpha, gamma, delta, mu, epsilon
- V, J, D and C
0 doest bind antigen specifically

217
Q

describe somatic recombination

A

RAG1 RAG2 and DNA repair enzymes will dsDNA break and join random V and J producing DNA found in mature B cell

218
Q

common inherited cancers

A

hereditary breast/ovarian: BRCA1 and BRCA2
LI-fraumeni: p53 gene
Retinoblastoma: RB1 gene
Familial andenomatous polyposis: APC gene

219
Q

how is v-src hyperactivated

A

c terminus is deleted thus the kinase can no longer be regulated

220
Q

what single point mutations can drive Ras to tumorgensis

A

Gly-Val

221
Q

explain CML

A

fusion of chromosome 9 and 22 (philedelphia chromosome))
- BRC and Abl: BRC will hyperactive kinase (Abl) activity

222
Q

which chromosome is often partially deleted in chromosomal actity found in retinoblastoma

A

chromosome 13

223
Q

whats RB1

A
  • 1st tumor supressor gene
224
Q

are oncogenes and TSG both inherited

A

no, oncogene
yes , TSG

225
Q

p53

A

dominant negative (explain)

226
Q

HPV

A

DNA tumour virus (binds and inactivates TSG and promotes environment favourable for virsu)

227
Q

loss of TSG p53 causes what

A

malignant tumour

228
Q

activation of oncogene Ras causes what

A

benign tumour

229
Q

whats PD-1 and how do cancers use it

A

it is a receptor for T cells
- T cells are inactivated when a ligand binds to their PD-1 receptor to avoid hyperactivity (we stop it when we don’t need it)
- cancers were able to suppress T-cell functions by expressiong PD-1 ligand (inhibits T cells which attack foreign things)

230
Q

which chromosome has the receptors for the measles virus

A

chromosome 1
- also measles cannot infect rodents they don’t have the receptors for it
- some humans

231
Q

explain how viral genomes are derives (2) AND EXPLAIN

A
  1. derived from Adenovirus (DNA)
    - infects all cells even non-dividing ones
    - vector not integrated in genome
    - transgene diluted and lost (not permanent)
  2. derived from retrovirus
    - infect dividing cells (HIV can infect without cell division)
    - trasngene and vector will be incorporated ( permanent )
232
Q

describe ADA-SCID

A

autonomous immune disease
- deoxyadenosime accumulates in your T-lymphocytes and kills them
- treatment : bone marrow transplants
- T-lymphocytes = responsible for stimulation of your B lymphocytes (antigen production)

233
Q

what is the mutation that causes 5% of RP

A

RPE65 gene

234
Q

Retinis pigmentosa

A

RP cells in the retina break over time causing tunnel vision

235
Q

how to solve RP

A
  • make vector from functional RPE65 gene into RPE with mutations to compensate
236
Q

CRISP

A

uses RNA molecule that corresponds to target DNA sequence
- just change crRNA to target different things
- increasing expression of w+ copy, will changing the original mutant to a w+

237
Q

explain how iPS works and example

A

induced pluripotent stem cells
-overexpressionf o 4 TF: Oct3/4, Sox2, c-Myc, Klf-4 in fibroblast is sufficient to reprogram the cells to beep,e pluripotent stem cells
- dont have to worry about immune response

ANAT 212 (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions