Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

MBG2040 > week2 > Flashcards

week2 Flashcards

1
Q

what is the Incomplete dominance:

A

BB, Bb and bb all differ phenotypically; Bb
is intermediate between homozygous phenotypes
ex. Flower colour (red, white, pink)

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

what is the Codominance

A

: BB, Bb and bb all differ phenotypically, but Bb
exhibits phenotypes of both homozygotes.
ex. Blood type

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

some genes have many ………….

A

Some genes have many
alleles

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

alleles can be……… or ……….

A

Some of these alleles are
common; others are rare.

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

is the frequency of particular allele same or different from population to population

A

Frequency of a particular
allele varies from
population to population.

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

how many alleles coexist in each allele

A

Only two alleles coexist in each cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the allelic series

A

An allelic series
describes the
dominance hierarchy
of multiple alleles

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

what is the null allele

A

A null allele is
nonfunctional.

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

how is the function of the hypomorphic

A

A hypomorphic allele
has partial function.

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

what does A transferase add

A

I
A Encodes A Transferase Which Adds
Acetylgalactosamine

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

what does B transfrase add

A

B Encodes A Transferase Which Adds
Galactose

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

what is the non functional transfrase

A

i Encodes A Non-functional Transferase

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

how is the formation of the AB blood type

A

These alleles are codominant — both alleles are fully expressed in the
heterozygote—-two distinct proteins are made. In this case two different
transferases are made.

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

what is the Wildtype Allele

A
  • a functional enzyme or other protein
    is produced
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is the Loss Of Function Allele

A
  • an enzyme or other protein is no longer being produced, is produced at lower levels, or is nonfunctional
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

can the wildtype allele dominant over the loss of the function

A

Often the wildtype allele is dominant over the loss of function allele

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

what is the haplosufficiency

A

Half as much protein is synthesized yet this is often sufficient to achieve the wildtype phenotype.

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

what is the Huntington’s disease example of

A

Dominant alleles can be gain of function mutations, in which the mutant allele produces a protein that has
increased (detrimental) function.
e.g. Huntington’s disease

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

what is the haploinsufficient

A

In the heterozygote, half as much protein is synthesized and this is not sufficient for a normal phenotype; haploinsufficient.

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

dominant lethal genes can be expressed in both ……….. and ………..

A

Dominant lethal genes can be expressed in both the heterozygote and the homozygote. Some consider Huntington Disease allele to be a dominant lethal allele. Bb lethal, BB lethal, bb not lethal

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

recessive lethal genes are only expressed in the ………

A
  • Recessive lethal genes are only expressed in the homozygote. Individuals homozygous for a Tay Sachs allele often die before the age of 3.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what are the mutant alleles forms

A

Mutant alleles may be dominant, recessive, incompletely dominant, or codominant

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

most genes encode …………

A
  • Most genes encode polypeptides.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

does the same genotype always produce the same phenotype

A

The determination of phenotypes is further
complicated by the fact that the same genotype does not always produce the same phenotype

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
what is the Penetrance
: The proportion of individual organisms having a particular genotype that express the expected phenotype - variation in the population
26
what is the Expressivity
: The degree to which a phenotype is expressed (mild to severe); variation in the individual
27
what is the compelet panatrance
identical genotype express the same phynotype100%
28
what is the constant expressivity
identical known genotype express the phynotype with no variation in the color or any difference
29
what is the incompelet panatrate
identical genotype express less than 100% phynotype
30
what is the variable expressivity
identical genotype produce the range of different phenotypes
31
what is the incompelet panetrance with the variable expressivity
identical genotype produce the varibility of phynotypes with different degree of difference and colors
32
what is the polydactyly example of
Polydactyly (extra fingers and toes) is not fully penetrant. If only half the genotype for polydactyly have extra digits, you would say that it shows 50% penetrance.
33
what is the expressivity
The degree to which a phenotype is expressed (mild to severe)
34
what does the split hand-foot syndrom shows
Split Hand-foot Syndrome is a rare autosomal dominant disorder that shows variable expressivity – involves the deficiency or absence of one or more central digits of the hand or foot
35
what does piebaldism shows
Piebaldism is a rare autosomal dominant disorder that shows variable expressivity – absence of cells called melanocytes in certain areas of the skin and hair
36
what does the huntington disease shows
Huntington Disease is a rare autosomal dominant disorder that shows variable expressivity in the time onset of the disease. – neuro-degenerative disease. It causes loss of muscle coordination, cognitive decline and dementia.
37
what cause the incompelet panatrance and variabke expressivity
Incomplete penetrance and variable expressivity are due to the effects of other genes and to environmental factors that can alter or completely suppress the effect of a particular gene
38
what enviornmental factors express the phynotypic expression
1. Age 2. Sex 3. Temperature 4. Chemicals
39
what is the norm of reaction
The range of phenotypes expressed by a single genotype nder different environmental conditions is referred to as the norm of reaction.
40
what is the phynocopy
Phenocopy: A change in phenotype arising from environmental factors that mimic the effects of a mutation in a gene
41
which phynocopy can produce by the thalidomide
the chemical thalidomide can produce a phenocopy of a rare dominant trait called phocomelia in which limb development is disrupted
42
how Phenylketonuria can b regulated
Phenylketonuria (PKU) symptoms can be avoided by regulating the intake of phenylalanine
43
how we can prevent the heart disease
Many people inherit genes that lead to a propensity for heart disease, but regulating diet and exercise can affect the occurrence (penetrance) and seriousness (expressivity) of the disease.
44
what is the Mendel’s Law of Independent Assortment
The inheritance pattern of one trait will not affect the inheritance pattern of another trait.
45
what is the Genetic Interaction
Different combinations of alleles from two or more genes can result in different phenotypes, because of interactions between their products at the cellular or biochemical level
46
what does Complementation means
Complementation occurs when two strains of an organism with different homozygous recessive mutations that produce the same phenotype, produce offspring of the wild-type phenotype when mated or crossed.
47
how does Complementation occur
Complementation will only occur if the mutations are in different genes
48
when does the complementation does not occur
Complementation will not occur if the mutations are in the same gene.
49
how many genes have the recessive mutant alleles that cause deathness
About 50 genes have recessive mutant alleles that can cause deafness in humans.
50
what is the A heterogeneous trait
: a mutation in any one of a number of genes can give rise to the same phenotype.
51
what is the ratio of the complementation
9:7
52
what is the Epistasis
: The masking of the expression of one gene by another. No new phenotypes are produced.
53
what is the epistatic gene
The “epistatic gene” does the masking
54
what is the hypostatic gene
The “hypostatic gene” is masked.
55
what is the phenotypic ratio of recessive epistasis
phenotypic ratio = 9:3:4 Recessive epistasis Homozygous recessives at one gene pair mask expression from the other gene. A/- b/b and a/a b/b have the same phenotype
56
what is the phenotypic ratio of dominant epistasis
phenotypic ratio = 12:3:1 Dominant epistasis One dominant allele at one gene masks expression from the other gene A/- B/- and A/- b/b have the same phenotype
57
what are the monohybrid type of the phynotypes and their ratios
Monohybrid 3:1 Complete dominance 1:2:1 Incomplete dominance or codominance 2:1 Recessive Lethal allele
58
what are the dihybrid type of phynotypes and their ratios
Dihybrid 9:3:3:1 Complete dominance 9:3:4 Recessive epistasis 9:7 Complementation 12:3:1 Dominant epistasis
59
what is the Pleiotropy
A single gene can be responsible for a number of distinct and seemingly unrelated phenotypic effects.
60
what are the examples of the Pleiotropy
Sickle Cell Disease * Respiratory problems, sickled cells, chronic infections, joint pain, enlarged spleen, stroke etc. Cystic Fibrosis * Mucus clogs the lungs and leads to infections * Mucus obstructs the pancreatic ducts creates digestion problems
61
inbred or hybrid lines are more strong
inbred lines of experimental species are often less vigorous than hybrid lines
62
what is the Inbreeding Depression
Inbred lines of self fertilized plants are homozygous for alleles that were present in the founding line.
63
what is the Heterosis
* When two different inbred lines are crossed, the hybrids are heterozygous for many genes.
64
what is the Hardy Weinberg principle:
Predicting genotypes through allele frequencies in a popula
65
when is Hardy Weinberg principle correct
This principle is correct…in the absence of evolutionary influences! 1. Nonrandom mating 2. Unequal survival 3. Population subdivision 4. Migration
66
what is the Dosage compensation
Dosage compensation is a way of equalizing gene expression in the face of different gene dosage.
67
are the x and y chromosoms pair during the meiosis
The X and Y chromosomes pair during meiosis, even though they are not homologous (the genes located on each are different)
68
how is the sex determination in the grasshoppers
* XX – female * XO – male * grasshoppers
69
how is the sex determination in the mammals
* XX – female * XY – male * XO – female * XXY – male * mammals
70
how many barr bodies do x0 women xxy men and xxx women have
X0 females have no Barr Bodies, XXY males have 1 Barr Body, XXX females have 2 Barr Bodies
71
females are hemizygous for which genes
females are functionally hemizygous for X-linked genes at the cellular level
72
how much of the cell is expressed by each allele
Approximately 50% cells express one allele, and 50% cells will express the other allele
73
what is the X-Inactivation
Early in development, one X chromosome is inactivated in each cell - the process is random, it is equally likely that the maternal or paternal X chromosome will be inactivated.
74
what is the genetic mosaic
Females that are heterozygous for X-linked traits are genetic mosaics.

MBG2040 (5 decks)

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