Genetics

Question 1

How are genes units for evolutionary change?

Answer 1

1 Inheritance – transmission of genetic information from one generation to the next

2 Variation – genetic variation that leads to the creation of new alleles that may result
in new trait expression

3 Adaptation – advantageous traits are advantageous because they facilitate survival

4 Selection – advantageous traits get passed on

Question 2

Types of evolutionary mechanisms are:

Answer 2

1. Natural Selection
2. Gene flow
3. Genetic drift
4. Artificial selection

Question 3

Natural Selection is:

Answer 3

When individuals of certain genotype are more likely to reproduce, survive and pass their alleles to the next generation than other individuals.

Question 4

Geneflow is:

Answer 4

transfer of alleles into or out of a certain population
(immigration or emigration)

Question 5

Genetic drift:

Answer 5

genes occurring at a certain
frequency in the larger population will occur at a
different frequency (more or less often) in a smaller
subset of that population.

Question 6

What are the types of genetic drifts?

Answer 6

1. bottle neck effect: only few individuals survive (natural disasters)
2. Founder Effect: a small number of individuals become isolated from a larger population, aka. inbreeding.

Question 7

Artificial Selection

Answer 7

‘guiding hand’ to obtain a specific result (trait)

Question 8

What type of processes are these evolutionary mechanism?

Answer 8

1. Natural selection: Non-random process that favors traits that help
   organism survive.
2. Genetic drift and gene flow: Random processes that change allele frequency in a particular population.
3. Non-random process that humans favor.

Question 8

What did Gregor Mendel do?

Answer 8

Conducted coordinated and meticulous quantitative experiments to conclude that inheritance is non-blending.

Question 9

What are the laws of Mendel?

Answer 9

1. Law of Segregation: Inheritance is particulate – each parent’s
   gamete (reproductive cell) has and passes on to offspring only one
   allele for a trait.
2. Independent assortment: Traits are the result of combining independent alleles from the parents.
3. The relationship between the genotype and phenotype depends
   on:
   a. the dominance (Y)
   b. recessiveness (y) of an allele
   c. the composition of each trait – whether it is homozygous (yy/ YY) or heterozygous (Yy).

Question 9

What was achieved in the Post-Mendelian genetics?

Answer 9

1. Genetics - branch of biology that deals with heredity and variation of organisms.
2. Chromosomes – carry the hereditary information (genes); depend on the arrangements of nucleotides in DNA.

Question 10

What are the variation of gene expression?

Answer 10

1. SNPs (Single nucleotide polymorphisms).
2. Gene mutations.
3. Linkage group and recombination.

Question 11

Important to note that:

Answer 11

SNPs - the variation must occur in more than 1% of population

Question 12

What is Genome wide association studies? and what is its goal?

Answer 12

A technique used to scan SNP markers across the entire genome of a large number of individuals in order to establish genetic variation associated with a specific trait.
Goal: to identify SNPs (and genes) associated with
disease.

Question 13

What are the types of mutations?

Answer 13

1. Deletion: A segment of DNA is lost or removed, resulting in the loss of genetic material.
2. Duplication: A segment of DNA is copied, leading to extra copies of that genetic material.
3. Inversion: A segment of DNA is flipped and reinserted in the opposite orientation.
4. Insertion: Additional DNA is added into a gene, altering its sequence.
5. Translocation: A segment of DNA is moved from one location to another, either within the same chromosome or to a different chromosome.

Question 14

Important to note about SNPs and gene mutation is:

Answer 14

all SNPs are a type of a mutation, but not all mutations are SNPs.

Question 15

What is heritability? How is it quantified?

Answer 15

The proportion of variation in a trait within a population that is due to genetic differences.
Heritability (h2) can be quantified as a number ranging from 0-1
– 0 no genetic contribution to variance
– 1 all variability in a trait is due to genetic differences.

Question 16

What is behavioral genetics?

Answer 16

study of the degree to which genetic variation explains phenotypes (variation in traits) including physical attributes, cognitive abilities, presence of mental illnesses etc.

Question 17

Behavioral Epigenetics:

Answer 17

Investigates the mechanisms by which the environment influences gene expression, which can potentially contribute to the development and manifestation of behavioral traits and disorders.

Question 18

If natural selection is still a mechanism of evolution, at what level does it work?

Answer 18

1. The selfish gene.
2. Reciprocal altruism.
3. Kin-selected altruism.
4. Group selection theory.

Question 19

Group selection theory:

Answer 19

Animals behave in a way they do to promote the survival and
well-being of their group; self-sacrificing, altruistic for the
benefit and reproductive success of a group.

Question 20

Kin-selected altruism:

Answer 20

Helping relatives to increase their reproductive success, boosting shared genetic survival.

Question 21

Inclusive fitness

Answer 21

Evolution of behaviors that benefit the individual and its close relatives.

Question 22

Reciprocal altruism.

Answer 22

Strategy that promotes cooperation and mutual benefit within a group, even if there is a short-term cost to the individual.

Question 23

The selfish gene.

Answer 23

Genes themselves are the primary units of selection and they act in
their own self-interest; genes that enhance their own survival and
reproduction are more likely to be passed on to future generations.