Chapter 12: Genetics and Evolution

Question 1

Homologues?

Answer 1

The two copies of each chromosome

Question 2

Incomplète dominance vs codominance

Answer 2

Incomplète: Red and white makes pink

Codominance: both expressed (AB blood type)

Question 3

What is penetrance ?

Answer 3

Proportion of the population with a given genotype who actually express the phenotype

Example: Huntington’s disease
- individuals with > 40 sequence repeats have «full penetrance»

In other words (100% of people with this allele show symptoms )

Question 4

What is expressivity?

Answer 4

Varying phenotypes despite identical genotypes

When constant: all with same genotype have same phenotype

When VARIABLE: individuals with same geno might have different phenotype

Question 5

Mendels first law (of segragration)

Answer 5

Two alleles segregate during meiosis …each gamete has one

Question 6

Mendels 2nd law: indépendant assortment

Answer 6

Crossing over, recombination

Question 7

What is a «wild-type» when talking mutations?

Answer 7

Allèles that are considered «normal»

Question 8

Name 5 types of chromosomal mutations

Answer 8

Deletion

Duplication

Inversion

Insertion

Translocation

Question 9

What is an inborn error of metabolism?

Answer 9

A type of deleterious mutation associated with metabolism

Question 10

What is genetic leakage?

Answer 10

Flow of genes between species

*can cause hybrids

Question 11

Genetic drift

Answer 11

Change in gene pool due to chance

Founder effect

Bottle neck

Question 12

What is a mono hybrid cross?

Answer 12

Only one trait is being studied

Question 13

Test cross

Answer 13

Used to determine an unknown phenotype

Cross with homozygous recessive

If 100% dominant, then homozygous dom

If 50% dominant, heterozygous

Question 14

Dihybrid cross

What is it and what are the phenotypic ratios?

Answer 14

Looking at two different genes

9: 3: 3: 1

Question 15

Are sex linked traits more common in males or females?

Answer 15

Mâles!

If they have it on their X chromosome then it will be expressed

Question 16

What are the five criteria for hardy Weinberg?

Answer 16

• no drift (large pop)
• no mutations
• no sex
• no migration in or out of population
• equal reproduction

Question 17

What is the hardy Weinberg equation?

Answer 17

P^2 +2pq + q^2 = 1

P + q = 1

Question 18

What does P and q represent in hardy Weinberg ?

Answer 18

P^2 is homozygous dominant
2pq is hetero
q^2 homozygous recessive

Question 19

What is fitness?

Answer 19

Level of reproductive success

Question 20

What is the the modern synthesis method? What’s another name for it?

Answer 20

Neo-darwinism

Darwins theory + genetic inheritance and changes in gene pool

Question 21

Explain divergent, parallel, convergent evolution

Answer 21

Divergent:
- common ancestor but they split appart forming different species

Parallel:
- related species evolve in similar ways over time

Convergent evolution:
- not sharing recent common ancestor …
- share similar characteristics
(Ie fish and dolphins)