Module 3 Unit 2: Variations in Gene Expression Flashcards

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1
Q

The Traits that we have learned from the previous units are considered?

A

qualitative traits

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2
Q

These traits are controlled by genes with a cumulative effect such that the phenotypes show small, gradual differences.

A

quantitative traits

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3
Q

Is an interplay between genetic makeup and environmental factors.

A

phenotypic variations

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4
Q

They are influenced by the type, number, and inheritance pattern of the gene/s.

A

phenotypic variations

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5
Q

Refers to the proportion of a population that will exhibit a particular trait if the allele is found in their genotype.

A

Penetrance or Quantitative Concept

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6
Q

100% of all individuals with the same allele in their genotype expresses the trait

A

Complete Penetrance

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7
Q

Not all individuals with the same allele in their genotype expresses the trait.

This is the type of penetrance exhibited by incomplete dominance, codominance, gene interaction, and epistasis.

A

Incomplete / Reduced Penetrance

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8
Q

Refers to the degree of expression of a penetrant gene

A

Expressivity / Qualitative Concept

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9
Q

Expressivity is dependent on?

A

penetrance

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10
Q

A trait must be __________ for expressivity to be assessed.

A

penetrant

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11
Q

Is a trait that is non- genetic

A

Phenocopy

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12
Q

Is due to an environmental factor but mimics a phenotype.

A

Phenocopy

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13
Q

These two terms refer to the expression of traits by members of monozygotic twins

A

Concordance and Discordance

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14
Q

If both monozygotic twins exhibit a trait, the trait is called?

A

concordant

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15
Q

It means that the trait has a genetic basis

A

Concordance

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16
Q

True or False:
Since monozygotic twins have exactly the same genetic composition, a genetic trait present in one member is also present in the other.

A

True

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17
Q

If a trait is exhibited by one member of a monozygotic twin but is not exhibited by the other member, the trait is?

A

discordant

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18
Q

If both members of a monozygotic twin were born deaf, then the trait most likely has a genetic basis, thus?

A

concordant

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19
Q

If only one member of the monozygotic twin is deaf, the condition cannot be genetic, thus considered?

A

discordant

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20
Q

Quantitative traits are governed by multiple genes thus referred to as?

A

polygenic traits

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21
Q

Each allele of each gene interacts ______ and contribute to the expression of that particular trait

A

Additively

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22
Q

Regions of the DNA that contribute to a quantitative trait are collectively referred to as ________ and located in different chromosomes

A

quantitative trait loci (QTL)

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23
Q

Most regions are protein-coding regions called ______, while some are __________ (thus not called genes) but still contribute to the trait

A
  1. genes
  2. regulatory regions
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24
Q

Quantitative traits are affected by both the DNA and the environment, thus called?

A

multifactorial

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25
Q

Is considerably variable because of the small continuous differences

A

polygenic trait

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26
Q

Is determined by the genes of an individual and the environment

A

Phenotypic Variance

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27
Q

Phenotypic Variance Formula

A

VP = VG + VE

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28
Q

Is determined by incomplete dominance, complete dominance, and gene interactions and epistasis

A

Genotypic variance

29
Q

Genotypic variance Formula

A

VG = VA + VD + VI

30
Q

Differences in the phenotype observed in a population

A

phenotypic variance

31
Q

Differences observed in a population that is due ONLY to the genotype

A

genotypic variance

32
Q

Differences observed in a population that is due ONLY to environmental factors

A

environmental variance

33
Q

Refers to the variance due to the total quantitative effects of each allele in a polygene

A

Additive Variance

34
Q

It is also known as the breeding value because it represents the worth of the genes to the next generation; how much would the genes contribute to the phenotype of the offspring

A

Additive Variance

35
Q

Refers to some genes that act on the same characteristic exhibit complete dominance

A

dominance variance

36
Q

Some genes that act on the same characteristic exhibit gene interactions

A

interaction variance

37
Q

Refers to the variance due to the interaction between genes at different loci.

A

interaction variance

38
Q

Refers to the percentage of phenotypic variation that is due to genotypic variations

A

Heritability

39
Q

The proportion of the phenotypic variation due to ALL the genetic factors

A

Broad Sense Heritability (H2)

40
Q

Broad Sense Heritability (H2) Formula

A

H^2= Vg/Vp x 100

41
Q

Proportion of the phenotypic variation based on the additive genetic variance

A

Narrow Sense Heritability (h2)

42
Q

It is a measure of how likely an offspring will resemble its parents

A

Narrow Sense Heritability (h2)

43
Q

It is important in determining how a trait will respond to selection

A

Narrow Sense Heritability (h2)

44
Q

Extremely important for breeding because it deals with traits that are of value for the next generation

A

Narrow Sense Heritability (h2)

45
Q

Narrow Sense Heritability (h2) Formula:

A

h2 = Va/Vp x 100

46
Q

If H2 = 0?

A

The phenotypic variance is due to environmental factors only

47
Q

If H2 = 100%?

A

The phenotypic variance is due to the genotype only

48
Q

If H2> 0?

A

the phenotypic variance is partly due to genotype

49
Q

If h2 = 0?

A

the phenotypic variance is due to environmental factors only

50
Q

If h2 =100%

A

the phenotypic variance is due to the additive genetic variance

51
Q

If h2> 0

A

the phenotypic variance is partly due to genotype

52
Q

Comes from the word “epi” which means outside and “genetics” referring to the genes

A

Epigenetics

53
Q

Refers to the study of factors that alter gene expression without changing the DNA nucleotide sequence.

A

Epigenetics

53
Q

Refers to the study of factors that alter gene expression without changing the DNA nucleotide sequence.

A

Epigenetics

54
Q

Molecules that alter gene expression either promote or prevent the transcription of genes. All these “gene expression-altering” molecules taken together make up the entire ______.

A

Epigenome

55
Q

T or F:
Most epigenetic changes are irreversible.

A

True

56
Q

All ________ daughter cells inherit the change,
thus remain throughout the lifetime of the organism.

A

mitotic

57
Q

Can occur if the epigenetic change is retained during gametogenesis, that is, the gametes still have the epigenetic change

A

Transgenerational epigenetic inheritance

58
Q

Functions to turn off gene expression

A

DNA methylation

59
Q

It prevents gene transcription, thus involved in gene silencing

A

DNA methylation

60
Q

T or F:
Histone proteins have tails that stick out of the nucleosome.

A

Histone modification

61
Q

Histone proteins have tails that are easily accessible for epigenetic modifications that alter the packaging of the DNA, to either promote or prevent transcription. This process is called?

A

Histone modification

62
Q

Non-coding RNAs (ncRNAs) are transcribed by the DNA but not translated to
proteins

A

Gene Silencing by ncRNA

63
Q

Aside from differentiation, epigenetic processes may also occur due to environmental factors that could trigger DNA methylation, histone modifications, and miRNA post-translational modification

A

Epigenetic Factors

64
Q

One allele (paramutagenic) will prevent the expression of another allele (paramutable). This is called?

A

Paramutation

65
Q

What is the rule in paramutation?

A

As long as the paramutagenic a is present in the genotype, the paramutable A is not expressed, thus the color of the corn kernel becomes light.

66
Q

One allele is marked via DNA methylation for silencing, while the other allele is expressed.

A

Genomic Imprinting

67
Q

Balances the expression of the X-linked genes in males and females

A

Dosage Compensation