1.2.1 - Mendelian Genetics Flashcards

1
Q

It is the branch of biology that deals with heredity and variation of organisms.

A

Genetics

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2
Q

It carries the hereditary information or the genes of an individual

A

Chromosomes

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3
Q

It is a type of chromosome that contain DNA that codes for the same genes
- they are alike but not exactly the same

A

Homologous chromosomes

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4
Q

These are exact replicas of each other

A

Sister chromatids

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5
Q
  • it is a unit of heredity
  • a section of DNA sequence encoding a single protein
A

Gene

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6
Q

It is the entire set of genes in an organism
- 1st to 23rd pair

A

Genome

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7
Q

These are two genes that occupy the same position on homologous chromosomes
-it covers the same trait
- ‘flavors’ of a trait

A

Alleles

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8
Q

It is a fixed location on a strand of DNA where a gene or one of its alleles is located

A

Locus

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9
Q

It is the genetic makeup of an organisms
- e.g. Tt, tt, Xx

A

Genotype

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10
Q
  • It is the physical appearance of an organism
  • Genotype + environment
A

Phenotype

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11
Q

It is having identical genes (one from each parent) for a particular characteristic
- TT, tt

A

Homozygous

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12
Q

It is having two different genes for a particular characteristic
- Tt

A

Heterozygous

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13
Q

It is a trait in which a gene is carried on a sex chromosome

A

Sex-linked trait

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14
Q

These are traits controlled by genes on one of 22 pairs of autosomes (non-sexual chromosomes)

A

Autosomal traits

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15
Q
  • It is the allele of a gene that masks or suppresses the expression of an alternate allele
  • the trait appears in the heterozygous condition
A

Dominant

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16
Q
  • It is an allele that is masked by a dominant allele
  • does not appear in the heterozygous condition, only in homozygous.
A

Recessive

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17
Q
  • a genetic cross involving a single pair of genes (one trait)
  • parents differ by a single trait
A

Monohybrid cross

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18
Q
  • a genetic cross between two different genes that differ in two observed traits
A

Dihybrid cross

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19
Q

What represents the Parental generation

A

“P”

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20
Q
  • What represents the First filial generation
  • offspring from a genetic cross
A

F1

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21
Q

What represents the second filial generation of a genetic cross

A

F2

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22
Q
  • It is the phenotype that is the most common expression of a particular allele combination in a population.
  • It may be recessive or dominant
A

Wild type phenotype

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23
Q

This phenotype is a variant of a gene’s
expression that arises when the gene undergoes a change, or mutation

A

Mutant phenotype

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24
Q

It is an illness that typically begins in early adulthood, causing uncontrollable movements and changes in behavior and thinking (cognition)

A

Huntington disease

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25
Q

Huntington Disease is an ________

A

Autosomal Dominant

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26
Q

It is a kind of disease that each child of an affected individual need inherit only one copy of the mutant gene to develop the disease

An example of this is the Huntington Disease

A

Autosomal Dominant

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27
Q

10% of people who have Huntington Disease are under the age of 20 y/o and acquired what we call ________

A

Juvenile Huntington Disease

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28
Q
  • This type of inherited disease affects each child independently
  • It affects every generation and both sexes (wala syang inii-spare)
A

Classic Autosomal Dominant Inheritance

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29
Q

True or False

The single-gene disease is distinctive with penetrance
- since all cells harbor the mutation, if the person has inherited it

penetrance = predictive ability

A

True

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30
Q

Another distinction of the single-gene disease is that mutations stay in certain populations because some tend to have children with people similar to themselves or their relative. This is what we call _______

A

Consanguinity (incest haha)

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31
Q

Sickle cell disease and Muscular dystrophy are examples of what type of disease?

A

Single-gene disease

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32
Q

This test is consisting of sick children and their parents which can reveal whether the child inherited two disease-causing mutations from carrier parents, or whether a dominant mutation arose anew

A

Tests of Trios

33
Q

It is a term used when an individual has a dominant mutation that arose anew
- did not inherit it from anyone

A

de novo

34
Q

It is the theory where traits of two parents “blend” together and inherited by the offsprin

A

Blending Theory of Inheritance

35
Q

What experiment counteracted the blending theory?

A

Mendel’s experiment with peas

36
Q

Why are peas ideal for probing heredity?

A
  • easy to grow
  • develops quickly
  • traits that take one of two easily distinguishable forms
37
Q
  • Inheritance that involves the passing of discrete units of inheritance, or genes, from parents to offspring
  • It is Mendel’s theory
  • aka the gene Idea
A

Particulate Theory of Inheritance

38
Q
A
39
Q

Medel was the first to discover that traits were passed on ______

A

intact

40
Q

What theory is this?

  • Genes are present within chromosomes inside the cell
  • Genes and chromosomes are in
    pairs in diploid cells
A

Chromosome Theory of Inheritance

41
Q

Who proposed and proved the Chromosome Theory of Inheritance?

A
  • proposed by Walter Sutton
  • proved by Thomas Morgan
42
Q

Patterns of Inheritance | What principle is this?

  • one allele masks another
  • one allele was dominant over the other in the F1 generation
A

Principle of Dominance

43
Q

Patterns of Inheritance | What principle is this?

When gametes are formed, the pairs of hereditary factors (genes) become separated, so that each sex cell (egg/sperm) receives only one kind of gene

A

Principle of Segregation

44
Q

Patterns of Inheritance | What principle is this?

Genes located on different chromosomes will be inherited independently of each other

A

Principle of Independent Assortment

45
Q

According to Mendel, short plants were ________ , while tall plants were _______

A

Short plants: True breeding
Tall plants: Non-true breeding

46
Q

Some dominantly inherited diseases are said to be due to a ________ because they result from the action of an abnormal protein that interferes with the function of the normal protein

A

gain-of-function

47
Q

Huntington disease results from ________ in which the dominant mutant allele encodes an abnormally long
protein that prevents the normal protein from functioning in certain brain cells.
- The protein encoded by the mutant HD allele must be abnormal, not absent, to cause the disease

A

gain-of-function

48
Q

What is the extra protein in the Huntington disease that causes a gain-of-function?

A

Huntingtin protein

49
Q

A single gene on chromosome ________, confers eye color by controlling melanin synthesis.
- If this gene is missing, albinism results, causing pale skin and red eyes
- recessive allele of this gene confers blue color and a dominant allele confers brown

A

Chromosome 15, OCA2

50
Q

Near the OCA2 gene on chromosome 15 is a second gene, ________, that controls expression of the OCA2 gene
- recessive allele of this gene abolishes the control over OCA2, and blue eyes result

A

HERC2

51
Q

A person must inherit two copies of the ____________ to have blue eyes.

A

recessive allele in HERC2

52
Q

A heterozygous individual is also a ________

A

carrier

53
Q

True or False

Carriers can develop a life-threatening breakdown of muscle if exposed to the combination of environmental heat, intense physical activity, and dehydration

Case for sickle cell disease

A

True

sicke cell trait

54
Q

True or False

Most genes have more than two alleles and more than two variations of the associated trait.

A

True

55
Q

An individual with two different recessive alleles for the same gene is termed as _______

A

Compound Heterozygote

56
Q

It is a variant that occurs when a child has a recessive allele from each parent w the variant located at a different position with the same gene

A

Compound Heterozygous Variant

57
Q

How is nucleotide inheritance determined?

A
  • Laboratory-based: 10x Genomics or fosmid pool-based strategy
  • Computer-based: SHAPEIT2, Eagle2, HapCUT2
58
Q

This disease may present in juvenile or adult onset forms, which is a result of the compound heterozygosity between two alleles, one that causes the classic infantile disease in homozygotes and another that allows some residual HEXA enzyme activity

A

Yay-Sachs disease

59
Q
  • It was the first genetic disorder for which mass post-natal genetic screening was available
  • It is a rare inherited disorder that causes an amino acid called phenylalanine to build up in the body
A

Phenylketonuria

60
Q

It is an inherited form of sickle cell disease that affects red blood cells both in the production of abnormal hemoglobin, as well as the decreased synthesis of beta globin chain

A

Sickle cell-beta thalassemia

61
Q

A recessive trait is sis to arise from a _______ because recessive allele usually prevents the production or activity of the normal protein

A

Loss-of-function

62
Q

Recessive diseases tend to be more severe, and produce symptoms earlier, than dominant diseases

A

True

63
Q

The half normal amount of the enzyme that a carrier produces is usually sufficient to maintain health. The one normal allele, therefore, compensates for the mutant one, to which it is dominant.

A

True

64
Q

Most autosomal recessive conditions appear unexpectedly in families, because they are transmitted silently, through ______

A

heterozygotes (carriers)

65
Q

In what situation can autosomal recessive condition be more likely to recur?

A

Blood relatives have children together — Consanguinity (“shared blood”)

66
Q

Identify whether it is Autosomal Dominant or Autosomal Recessive or both

Makes and females are affected with equal frequency

A

Both

67
Q

Identify whether it is Autosomal Dominant or Autosomal Recessive or both

Successive generations affected until no one inherits the mutation

A

Autosomal Dominant

68
Q

Identify whether it is Autosomal Dominant or Autosomal Recessive or both

Affected individual has an affected parent, unless he/she has a de novo mutation

A

Autosomal Dominant

69
Q

Identify whether it is Autosomal Dominant or Autosomal Recessive or both

It can skip generations

A

Autosomal recessive

70
Q

Identify whether it is Autosomal Dominant or Autosomal Recessive or both

Affected individual has parents who are affected (both) or are carriers (at least one)

A

Autosomal recessive

71
Q

This law reflects the actions of chromosomes and the genes they carry during meiosis

Two Factors:
- equal allele distribution into gametes
- random combinations of gametes

A

Law of Segregation (Mendel’s 1st Law)

72
Q
  • This law states that for two genes on different chromosomes, the inheritance of one gene does not influence the chance of inheriting the other gene
  • The two genes are packaged into gametes at random
A

Law of Independent Assortment (Mendel’s 2nd Law)

73
Q
  • It is a useful tool to do genetic crosses
  • Looks like a windowpane
  • Used to determine the probability of outcome of offspring
A

Punnett square

74
Q
  • It is a lethal genetic disease affecting Caucasians
  • It is caused by a mutant recessive gene carried by 1 in 20 people of European descent
  • It affects transportin tissues – mucus is accumulated in lungs, causing infections.
A

Cystic Fibrosis

75
Q
  • It is a fatal genetic disorder that causes the progressive breakdown of nerve cells in the brain
  • aka quintessential family disease because every child of a parent with HD has a 50/50 chance of inheriting the faulty gene
  • it’s allele is dominant
A

Huntington Disease

76
Q

It is a mating that involve parents that differ in two genes (two independent traits)

A

Dihybrid cross

77
Q

What is the common phenotypic ratio for a dihybrid cross?

A

9:3:31

78
Q
  • You do this test when you have an individual with an unknown genotype
  • It is a cross with a homozygous recessive individual
A

Test cross