Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

GENETICS > Exam 1 Units 1-3 > Flashcards

Exam 1 Units 1-3 Flashcards

(95 cards)

Start Studying
1
Q

Mendel’s Law of Segregation

A

the 2 copies of a gene segregate from eachother duing the process that gives rise to gametes

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

Mendel’s Law of Independent Assortment

A

the alleles of different genes sort independently of one another

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

What is genetic recombination?

A

when an offspring receives a combination of alleles that differ from the parental generation. either due to independent assortment or crossing over

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

Isogamy

A

sexual reproduction strategy where gametes are the same size and shape

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

What happens if you have loss of function alleles of SRY or SOX9?

A

in XY individuals- typically results in female-associated secondary characteristics (including a uterus) but no primary sex differentiation (no testes or ovaries)

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

Anisogamy

A
  • gametes are different shapes and sizes
    • Larger gametes female (egg)
    • Smaller gametes male (sperm)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Why do we use the Chi-squared test?

A

To determine “goodness of fit” or how close the observed data are to those predicted from a hypothesis

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

does SOX9 promote male or female differentiation?

A

promotes male differentiation

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

does SRY promote male or female differentiation?

A

promotes male differentiation

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

does RSPO1 promote male or female differentiation?

A

promotes female differentiation

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

does WNT4 promote male or female differentiation?

A

promotes female differentiation

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

In X-linked inheritance, do males receive their X from their mother, father, or both?

A

Males receive their X from their mother

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

What is a Dominant Negative mutation?

A

the mutant allele has both lower function & the ability to block the wildtype allele

heterozygote has too little function to produce the wildtype phenotype

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

What happens if you have loss of funtion alleles of RSPO1?

A

in XX individuals- typically results in male-associated primary and secondary sex characteristics

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

What happens if you have loss of funtion alleles of WNT4?

A

in XX individuals- typically results in underdeveloped female-associated secondary sex characteristics

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

In X-linked inheritance, do fathers pass their X to the daughters, sons, or both?

A

only to their daughters

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

what is a Recessive Loss of Function mutation?

A

the mutant has a lower expression or function than the wildtype

the heterozygote has enough expression or function to produce the wildtype phenotype

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

what is hemizygous

A

having an X and a Y instead of two copies of one (i.e. XX)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is expressivity

A

the degree of phenotype expressed in an individual

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

What is dominant haploinsufficiency (loss of function)?

A

the mutant has lower expression or function than the wild type

heterozygotes have too little expression or function to produce wildtype phenotype

wildtype is dominant, but haploinsufficient

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

What is a Gain-of-Function mutation?

A

the mutant allele has a new expression pattern or function

heterozygote has the expression pattern or function of both the wildtype and mutant allele

ex: protein expression driven in a new part of the body

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

When do we use the product rule?

A

For independent (shared) events co-occurring in a sequence ie: “AND THEN”

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

What is Incomplete Dominance?

A

heterozygotes are distinguishable from both homozygotes

ex: homozygotes: red and white flowers, heterozygotes: pink flowers

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

When do we use the sum or addition rule?

A

For mutually exclusive (complex) events. ie: “OR”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is Codominance?
the full expression of 2 alleles are present simultaneously in the heterozygote
26
What is penetrance?
the _frequency_ of a phenotype for a given genotype in a population
27
Explain this Reaction Norm:
the Genotype influences phenotype, No environmental impact
28
Explain this Reaction Norm:
Both genotype and environment influence phenotype G and E independent of one another
29
Explain this Reaction Norm:
Environment influences phenotype, no genotype influence
30
Explain this Reaction Norm:
Genotype and environment influence phenotype G and E interaction
31
What is the Quick Dominance Test for pedigrees?
Look for offspring that have the **opposite** phenotype as **both parents**. If you find this, the phenotype of the offspring is r**ecessive**
32
What is the binomial expansion equation and when should you use it?
P = (n!/x!(n-x)!)pxqn-x P= probability n= total number of events x= number of events in category of interest p= individual probability of x q= individual probability of the other categories It should be used when the events are unordered
33
What is the Quick Autosomal Test for pedigrees?
If there are any females with the recessive phenotype that have a **father or son** with the dominant phenotype then the gene must be **autosomal**
34
What is Horizontal Gene Transfer?
it allows for the exchange of DNA without involving gametes
35
What are the common mechanisms for Horizontal Gene Transfer?
Conjunction (direct) Transformation (Environmental DNA) Transduction (Virus mediated)
36
What are the phases of mitosis?
Prophase → metaphase → anaphase → telophase
37
What are the phases of meiosis and what kind of gametes do they produce?
Prophase I → metaphase I → anaphase I → telophase I → prophase II → metaphase II → anaphase II → telophase II They give four sex gametes
38
What are the purines? Are they large or small?
A/G large
39
What are the pyrimidines? Are they large or small?
T/C small
40
Dideoxy nucleotides are used in which technique? Restriction mapping, DNA sequencing, RT-PCR, Gene cloning, DNAse I foot printing
DNA Sequencing | (Sanger)
41
You are carrying out a sequencing reaction. You remember to add ddNTPs, but forget to add dNTPs. What will the outcome of your sequencing reaction be?
Sequencing will begin, but will not be able to proceed past the first nucleotide because the ddNTPs cannot be used for chain extension.
42
Which repair mechanism often leads to deletions in chromosomes?
Non-homologous end joining (NHEJ)
43
You are analyzing a human pedigree for a new disease and discover that the disease occurs with the same frequency in both sexes and that 25% of the children from two unaffected heterozygous parents have the disease. This disease is displaying __________ inheritance. sex-linked dominant autosomal recessive autosomal dominant sex-linked recessive
autosomal recessive
44
Consequence of depurination?
can have any outcome- Loss of A or G means that any nucleotide can be introduced on the complimentary strand
45
Consequences of DNA polymerase errors?
Can have any outcome
46
Consequences of deamination?
converts a C-G pair to a T-A pair C → T and G → A
47
Consequences of Tautomerization?
interconverts partners without changing the sizes of the nitrogenous base. has 4 possible outcomes: A→G, G→A, C→T, or T→C
48
Consequences of Oxidation?
G→T, C→A | (G-C → T-A)
49
Cause of depurination?
Covalent bond between deoxyribose and purine base (A or G) reacts with water and releases the base site is Apurnic (AP)
50
Cause of Deamination?
removal of Amine (NH2) group from cytosine generates uracil
51
Cause of tautomeric shift during replication?
temp shift of Hydrogen in thymine or cystosine during replication
52
To cause a mutation, when much tautomerization occur?
IMMEDIATELY prior to replication when the 2 strands are split open
53
Cause of Oxidative DNA Damage?
Reactive oxygen species created in our bodies (mitochondrion, some metabolic processes)
54
Why do you run an Ames Test?
Mutagenicity in bacteria → mutagenicity in Humans → risk of cancer in humans
55
what does a large number of colonies suggest in an Ames Test?
that the mutagen causes the mutation
56
Explain the method of the Ames Test
bacteria with a loss of function mutation in histidine are used one treated with potential mutagen and one left as control select for cells with a reversion mutation enabling growth on a media lacking histidine
57
How to you determine the mutation rate with an Ames Test?
colonies / plated cells
58
What is direct repair?
a single enzyme has direct recognition of damage that it simply reverses
59
What does base excision repair do?
Fixes mutations which don't distort the double helix
60
what is the mechanism of base excision repair?
abnormal base removed (by N-glycolases) AP endonucleases cut on the 5' side of the AP base (creates a nick) DNA pol replaces the damaged nucleotide Nick is repaired by ligase
61
Nuclotide Excision repair can repair what types of mutations?
Helix distorting changes to DNA | (ex- thymine dimers)
62
What is the mechanism of Nucleotide Excision Repair?
Recognize distortion of DNA separate double helix endonuclease cuts bracket out DNA Pol synthesizes correct complementary strand Ligase closes
63
What does mismatch repair do?
Detects and repairs mismatches introduced during replication
64
What types of mutations can mismatch repair fix?
DNA Pol Errors, Tautomeric Shifts during replication
65
What types of mutations can base excision repair fix?
deamination, depurination, and oxidative DNA damage
66
Distinguish Nonhomologous end joining (NEJ) from homologous recombination (HR)
Both repair double strand breaks, but HR requires homologous DNA strands as a template to repair a break. NHEJ does not require a template. NHEJ can create a deletion or insertion
67
What is the binomial expansion equation and what does each variable stand for?
n = total # of events x = # of events in specific category p = probability of x (fraction) q = probaility of other category
68
When do you use a Binomial Expansion Equation?
when you have 2 outcomes (x or not x) events are independent - ex brown eyes (B) blue eyes (b) Bb x Bb have 5 children Probability that 2 of 5 will have blue eyes?
69
Who confirmed the chromosome theory of inheritance and established inheritance patterns for X-linked genes? What model system did they use?
Thomas Morgan Fruit flies
70
Define testcross.
A method used to determine the genotype of an organism with a dominant phenotype. In order to do this, you cross an organism with a dominant phenotype with an organism with a recessive phenotype.
71
Sex differentiation in anisogamous eukaryotes
Fruit fly female XX and male XY C. Elegans female XX and male XO Female bees give male bees and male and female bees give females (Haplodiplod)
72
Hyperandrogenism (adrenal hyperplasia)
high androgen levels (high testosterone, low cortisol) recessive autosomal most common DSD
73
Androgen insensitivity
cells have a lower response to testosterone recessive X-linked
74
What does wildtype mean on an organismal and molecular level?
Molecular level: They produce the typical function of the organism organismal level: produce the typical phenotype of the organism (1%+ of pop.)
75
What does mutant mean on a molecular and organismal level?
Molecular level: altered or lost molecular function organismal level: produce atypical phenotype
76
Define monogenetic
involving or controlled by one gene
77
fully penetrant
the gene(s) for a trait are fully expressed in those who have the gene(s) i.e- phenotype fully expressed for a given genotype
78
conventions of a pedigree
square = male circle = female people who marry in are considered homozygous and unaffected
79
What is Sanger Sequencing and how do you do it?
Allows you to figure out the sequence of an unknown piece of DNA Using a dideoxyribonucleotide (ddNTP) we are able to terminate DNA production. We can do this for all nucleotides and then run them all gel electrophoresis to measure the sizes of each dNTP
80
How do capillary sequencers improve the Sanger Sequencing method?
By adding GFP to color each dNTP we are able to use one capillary tube to run the sequencing for the DNA. This also allows longer DNA strands to be sequenced
81
What is a polymerase chain reaction (PCR) test and how do you perform it?
This is a process that allows us to amplify a certain chunk of DNA This is done through thermal cycling of 98 C (denature) to 55 C (anneal) to 72 C (elongation).
82
what is shotgun sequencing and how do you perform it?
this is a technique for sequencing DNA by chopping it up and sequencing random pieces of a genome. In this method, you sequence each piece many times and computers will match up the sequences later to create the full genome.
83
what does next-generation sequencing allow you to do?
It allows you to sequence millions to billions of sequences simultaneously
84
Distinguish between balanced and unbalanced chromosomal level rearrangements
Balanced mutations have no loss or gain of genetic material and are only due to a “chunk” of DNA going from it’s ordinary environment to a new environment (i.e. inversions, translocations) Unbalanced mutations have a loss or gain of genetic material (i.e. deletion, duplication)
85
What is the cause and potential consequence for chromosomal inversions? (or inversion loops). Can this lead to inviable offspring? If so, How?
2 double stranded breaks in a chromosome are repaired in the opposite orientation by NHEJ. There is typically no loss of genetic material but can alter the function of genes near the breakpoints. During meiosis - Only 50% of offspring are viable
86
What is the cause and potential consequence for chromosomal translocations? Can this lead to inviable offspring? If so, How?
movement of pieces between chromosomes and is repaired by NHEJ. Has the same issues for breakpoints as inversions (can alter the function of genes near the breakpoints). Only ½ the possible gametes can produce viable offspring
87
What is the cause and potential consequence for chromosomal deletions?
(Removal of chromosomal material) arise from double strand breaks or from misaligned homologous chromosomes. Crossing over of misaligned homologs can result in deletion in gametes
88
What is the cause and potential consequence for chromosomal duplications?
(extra copies, or a repeating portion of a chromosome) Can arise from misaligned homologs. Crossing over of the misaligned homologs can result in duplications in gametes
89
What is aneuploidy
_individual_ chromosomes are in excess or are lost
90
What is polyploidy
when you have more than 2 _complete sets_ of chromosomes
91
What is nondisjunction
failure to segregate
92
Explain how nondisjunction can lead to aneuploidy
Nondisjunction or failure of segregation during anaphase can cause aneuploidy when you have an odd number of homologs attempting to assort equally (they cannot) You end up with _individual_ chromosomes in excess or lost
93
Explain how nondisjunction can lead to polyploidy
Failure of segregation during anaphase can lead to Polyploidy if one gamete ends up with the _complete set_ of chromosomes. When a haploid gamete fuses with the diploid gamete it becomes a triploid zygote
94
Describe why triploidy and other odd numbered ploidys are sterile
during segregation of homologous chromosomes (anaphase I) the odd numbered chromosomes have to go to one or the other side. The result is gametes with different numbers of copies of various chromosomes
95
List examples of human aneuploidy
3 autosomes (13, 18, 21) and the sex chromosomes

GENETICS (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions