Population Genetics

Question 1

What is the biological definition of evaluating?

Answer 1

Mutation ———————author

Natural Selection———-editor

Genetic drift ——————the randomizer

Gene flow———————-the homogenizer

Question 2

The definition of population genetics ?

Answer 2

1-Mathematical Aspects Of Genetics
How genes are distributed & maintained
at particular frequencies in populations

2- study genetic variation within a gene pool and how such
variations change from one generation to the next.

Question 3

The definition of gene pool ? How we can contribute them ?

Answer 3

1- All alleles in a population

2- total of all genes within the population or locus.

Contribute to gene pool by reproducing.

Question 4

Definition of population and local population ?

Answer 4

group of individuals same species.

small groups of the population determined by a geographical feature

Question 5

Definition of polymorphism, monomorphic and single nucleotide polymorphism?.

Answer 5

Polymorphisms: variation of traits influence phenotype
presence of a gene with multiple alleles (genetic variation, more
than one allele).

Monomorphic: single allele

Single-nucleotide polymorphism: commonest and smallest. SNPs

is a substitution of a single nucleotide at a specific position in the genome, that is present in a sufficiently large fraction of the population

Question 6

How many allele the locus and individual have?

Answer 6

Locus more than 2 alleles

Individual only 2 alleles

Question 7

What population genetics want to understand ?.

Answer 7

1-Why dominant trait does not increase at the expense of a recessive one

2-How carrier frequency can be calculated knowing the disease incidence

3-Why particular genetic disorder more common in one population than another?

Question 8

Genetic structure describes…………..and …………..?

Answer 8

Allele and phenotype frequencies

Question 9

What is the equation of for genetic equilibrium?

Meaning of p / q ?.

Answer 9

P^+2pq+q^=1
P= dominant allele (represented here by A)
q= recessive allele ( represented here by a)

Question 10

Who put the genetic equation?.

Answer 10

HARDY-WEINBERG LAW

Question 11

Allele frequencies measure ……….while genotype frequencies shows ……….. and both describe ……..?

Answer 11

genetic variation

distributed

population’s genetic structure.

Question 12

When dose the allele frequencies change ?.

Answer 12

Mutation , migration and selection

Question 13

The conditions to be met for a population to be hardy Weinberg equilibrium-are ?.

Answer 13

1- mating is random
2- Population size is very large.
3- no migration
4-no mutation.
5-Natural selection does not affect the alleles

Question 14

What happen if we make ideal condition for the population?

Answer 14

1- The frequencies of alleles at a locus will
constant from generation to generation.

2- genotype frequencies will not change

Question 15

The type of the disease PKU ? What the results of it ?

Answer 15

autosomal recessive metabolic disorder

mental retardation if untreated during the newborn
period.

Question 16

Why it is useful to use HARDY-WEINBERG EQUATION

Even if it is impossible to the conditions it’s need ?.

Answer 16

1- predicting genotype frequencies from allele
frequencies
2- help identify specific mechanisms of evolution
3- prompt a search for factors that cause the-deviation
e.G. Heterozygote advantage

Question 17

HARDY-WEINBERG -uses are ?

Answer 17

1- assumed populations in
equilibrium for most genetic traits (unless there is evidence to the contrary)

2- Carrier frequencies of an autosomal recessive disorder
3- Important for genetic counselling

Question 18

Method of calculating carrier frequencies?

Answer 18

جذر Disease incidence
اطلع منه p
2pq

================+========================
doubling the square root of the disease
incidence i.e. 2 x 1/100

Question 19

Factors Disrupting Hardy - Weinberg Equilibrium?

Answer 19

1- Source of new allelic/genetic variation:
– Mutation

2 - Mechanisms that alter existing genetic variation:
Migration (in and out)
– Positive or negative selection
– Genetic drift – chance fluctuations (smallpopulations)
– Non-random mating

Question 20

Example of mechanism happens when there are large deviations are found?

Answer 20

exposure to environmental toxins

Question 21

Example of Heterozygote Advantage?.

Answer 21

▪ Sickle-cell disease

Question 22

Explain Genetic drift and population bottlenecks?

Answer 22

If populations are reduced to a small number of individuals - a population bottleneck, genetic drift can reduce the genetic variation

Question 23

What inbreeding and outbreeding increases?.

Answer 23

Inbreeding leads to an increase in homozygosity
(assortative mating)

Out breeding leads to an increase in heterozygosity