Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

MCM Final > Principles Of Genetic Inheritance > Flashcards

Principles Of Genetic Inheritance Flashcards

(56 cards)

Start Studying
1
Q

Wildtype is also known as what

A

Normal

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

Lyonization is also known as what?

What does it create?

A

Known as x-inactivation, which occurs early in development

Condensation of one X creates a Barr body.

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

Mosaicism, what is it?

A

In women, when X heterozygous, some cells express the wildtype gene, some express the mutant gene.

These cells will exhibit different phenotypes

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

What event occurs in interphase?

A

Chromosome duplication

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

What is unique about stem cell mitosis?

A

It is asymmetrical, meaning that one stem cell and one daughter cell is produced.

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

Steps of mitosis

A 
Interphase
Prophase
Prometaphase
Metaphase
Anaphase
Telophase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How many cells are produced in meiosis?

A

4 haploid gametes

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

Euploid

A

Cells with normal number of chromosomes

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

Polyploid

A

Complete extra set of chromosomes

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

Aneuploidy

A

Missing or additional chromosomes—monosomy or trisomy

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

What is translocation?

What are the two types?

A

Non homologous chromosomes exchange genetic material.

Reciprocal—between non homologous chromosomes

Robertsonian—long arm of two Afrocentric chromosomes are combined. SHORT ARM IS LOST

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

Turner syndrome

  1. Karyotype
  2. Physical effects
A
  1. 45, XO
2.
Female
Short
Ovarian hypofunction or failure
No puberty
Web neck
Low hair line
Normal intelligence
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Klinefelter syndrome

  1. Karyotype
  2. Physical effects
A
  1. 47, XXY

2.

  • Varying degrees cognitive, social, behavioral, and learning difficulties
  • low T
  • small/undescended testes
  • tall
  • gynecomastia
  • infertility
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Trisomies

  1. Name
  2. Karyotype
  3. Additional info
A
  1. Trisomy 21, (Down’s syndrome)
  2. 47, XX +21
  3. Most common/stable, increased risk with maternal age, can also occur due to translocation
  4. Trisomy 13, (patau syndrome)
  5. 47, XX+ 13
  6. Severe dev abnomralities, death within 1 week
  7. Trisomy 18 (Edwards syndrome)
  8. 47, XX+18
  9. Abnormal development, death within one year
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is genomic imprinting?

A

One allele is transcriptionally inactive depending on the parent it was received from.

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

~30 genes are paternally imprinted.

This means?

A

They are maternally expressed

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

~70 genes are maternally imprinted.

This means?

A

They are paternally expressed.

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

Explain genomic imprinting in terms of somatic vs germ cells

A

Somatic cells—imprinting remains throughout the lifespan of the individual.

Germ cells—imprinting resets at each generation

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

Prader-Willi syndrome

A

Deletion of region of chromosome 15 in the PATERNAL chromosome.

Prader-Willi kids will be short, obese, have small hands, and intellectual disabilities.

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

Angelman Syndrome

A

Deletion of a region of chromosome 15 on MATERNAL chromosome

Angelman kids will have severe intellectual disabilities, seizes, and ataxic gait.

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

What is uniparental disomy and how does it happen?

A

Two chromosomes are inherited from the same parent—this results in no gene product due to parent specific imprinting.

This is related to non-disjunction

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

What are the 3 Mendelian genetic mechanisms of disease?

A

Loss of function: dystrophin»Duchenne MD
Gain of function: oncogene»cancer
Protein alteration: beta-globulin»sickle cell anemia

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

Individuals with distinct geneotype can have one phenotype.

What is an example of this?

Study These Flashcards
A

Cystic fibrosis
There are different classes of CF, meaning there are different gene mutations that result in the same disease (phenotype)

24
Q

Individuals with the same genotype can have multiple phenotypes.

What is this called and what is an example?

Study These Flashcards
A

Known as pleiotropy

PKU is an example

25
What is a proband?
First diagnosed person in a pedigree
26
Describe autosomal dominant inheritance What is an example?
- Only 1 allele of gene needed for expression - unaffected individuals do not transmit - affected offspring have 1 affected parent - expected in every generation Example: POSTAXIAL POLYDACTYLY
27
Describe autosomal recessive inheritance What is an example
-2 copies of the gene are needed to influence phenotype Example: TYROSINE-NEGATIVE ABLINISM
28
Describe x linked recessive What is an example
- Disease allele on X - When occurs in male, we say they are HEMIZYGOUS - females can be hetero- or homozygous Example: DUCHENNE MUSCULAR DYSTROPHY
29
Describe X linked dominant What is an example
Very rare: no carriers - males with allele transmit the trait only to females %100 of the time - females with the disease transmit to male and female 50% of the time. Example: HYPOPHOSPHATEMIA
30
What is penetrance
The frequency a gene manifests itself.
31
Retinoblastoma
- Autosomal dominant | - occurs in 90% of individuals>>90% penetrance
32
Variable expressivity Example
Describes the range of phenotypes that vary between individuals with a specific geneotype. Example: Neurofibromatosis Tumor like growths, have cafe-au-lait spots, spots different in number, shape, and size
33
Locus heterogeneity Example
Single disorder, trait, or pattern of traits caused by mutations in genes at different chromosomal loci Example: osteogenesis imperfecta - brittle bones - mutations in collagen genes - chromosome 7, 17
34
Multiplication rule
Probability of a given outcome in multiple trials is the product of the probabilities of each trial outcome. Ex: what the probability of producing 3 girls? 1/2 x 1/2 x 1/8 = 1/8 What is the probability or producing 3 boys? 1/2 x 1/2 x 1/8 = 1/8
35
Addition rule
Probability of either one outcome or another is the sum of two probabilities What is the probability of producing 3 girls or 3 boys? 1/8 + 1/8 = 1/4
36
What is a gene frequency?
The proportion of each allele in a population. #of alleles in question/# of alleles present total
37
What is a genotype frequency?
Proportion of each genotype in a population of genotypes/ # of subjects
38
What is the Hardy-Weinberg principle and what is the equation.
A relationship between the gene frequency and genotype frequency p^2+2pq+q^2=1
39
Consanguineous mating leads to what?
More likely to have offspring affected by rare autosomal recessive disorders Mortality rates of offspring of first cousins are 9% higher than the general population
40
How do we inherit mitochondrial DNA?
Maternally
41
Why is the mutation rate for mitochondrial DNA higher? How much higher?
This is due to the lack of DNA repair mechanisms, as well as damage from free oxygen radicals released during OxPhos. It is 10x higher!
42
There is a ____ that must be met before some mitochondrial diseases present?
A threshold. When the percentage of mutant mitochondria reaches a certain level, then symptoms may arise.
43
Leber’s hereditary optic neuropathy (LHON)
Associated with mutation in mitochondrial DNA (mtDNA) - degeneration of retinal ganglion cells - acute or subacute loss of central vision - typically early teens/20s
44
Mitochondrial encephalomyopathy, lactic acidosis, and stroke like episodes (MELAS)
Associated with mutations in mtDNA - affects many body systems, particularly brain, nervous, and muscle tissues. - stroke and dementia - lactic acidosis.
45
Some traits are polygenic, what does this mean?
The variations in the trait are caused by the combined effects of multiple genes
46
When is the term multifactorial used when referring to gene mutations?
When environmental factors cause the variation in the trait
47
What type of traits usually follow a normal/bell shaped distribution in populations?
MULTIFACTORIAL, caused by environment and multiple genes.
48
Pyloric stenosis
Multifactorial inheritance Muscular hypertrophy between stomach and duodenum, leads to vomiting and obstruction. - five times more common in males, males need less risk genes to show the disease - children of women with pyloric stenosis are more likely to be born with the condition. - children of affected males, are less likely to be born with the condition
49
The recurrence risk for multifactorial inheritance is ________ if more than one family member is affected
Higher
50
What are three broad classes of cells in the human body?
Permanent, stable (quiescent), labile
51
What cells remain in G0 and cannot be regenerated?
Permanent cells. These include the following: Cardiac muscle cells, neurons, and red blood cells.
52
what cells are able to exit the G0 phase and enter G1 when stimulated by growth factors?
Stable cells, including the following: | Hepatocytes, epithelial cells of the kidney tubules.
53
What cells never enter G0 and are constantly dividing to replace the cell population?
Labile cells, including the following: | Gut epithelium, skin, hair follicles, and bone marrow.
54
Somatic cells vs germ-line cells
Somatic—Diploid, contain 46 chromosomes. Germ-line—Haploid, contain 23 chromosomes.
55
What is a karyotyping?
Technique that allows the determination of the number, size, and gross structure of metaphase chromosome. Used to identify genetic abnormalities.
56
What is heteroplasmy?
Presence of more than one type of mitochondrial DNA within a cell or organism. Symptoms usually don’t develop until adulthood, as these mutant mitochondrial alleles must undergo many cell decisions before the threshold is reached.

MCM Final (12 decks)

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