Mendelian Inheritance

Question 1

What shape are females in a pedigree? Males?

Answer 1

Females = Circles
Males = Squares

Question 2

How to distinguish affected individuals in a pedigree?

Answer 2

They are colored in!

Question 3

Mendel’s 3 Laws of Inheritance

Answer 3

Question 4

Law of Segregation

Answer 4

alleles for each gene separate from each other s that each gamete only carries one allele

Question 5

Law of Independent Assortment

Answer 5

genes for different traits can segregate independently during gamete formation

Question 6

Law of Dominance

Answer 6

some alleles are dominant while others are recessive

Question 7

Mendelian traits

Answer 7

controlledby a single locus following a pattern of inheritance; this means a mutation in a single gene can cause disease

Question 8

Genotype and Phenotype Ratios

Answer 8

can be made from Punnett Squares, see below

Question 9

Dihybrid cross

Answer 9

2 independent loci (cannot be used for traits that are linked/inherited together)

Question 10

3 Types of Dominance

Answer 10

1. Complete
2. Incomplete
3. Co-dominance

Question 11

Incomplete Dominance

Answer 11

results in an intermediate phenotype for heterozygotes (think red and white flowers, but also pink)

Question 12

Co-Dominance

Answer 12

heterozygotes will express both alleles (ex: blood type)

Question 13

5 Modes of Inheritance

Answer 13

1. Autosomal dominant
2. Autosomal recessive
3. X-linked dominant
4. X-linked recessive
5. Y-linked

Question 14

What mode of inheritance will only affect males?

Answer 14

Y-linked

Question 15

What modes of inheritance can skip generations?

Answer 15

autosomal recessive and X-linked recessive

Question 16

Y-linked

Answer 16

pssed form generation to generation (no skips), present in all males

Question 17

Autosomal Dominant

Answer 17

every affected offspring will have an affected parent; unaffected individualas mating will always have unaffected offspring

Question 18

How do autosomal dominant traits stay in the population?

Answer 18

via heteroygotes; they are very commonly homozygous lethal

Question 19

X-linked dominant

Answer 19

every offspring has affected parent; affected fathers will only pass trait to all daughters, no sons

Question 20

Which affects more males than females - X-linked dominan or recessive?

Answer 20

X-linked recessive

Question 21

Mitochondrial Inheritance

Answer 21

usually inherited from mother (because you get your mitochondria from your momma) but can also be a result of mutations

Question 22

Easy way to rule out dominant inheritance patterns?

Answer 22

if affected individual does not have an affected parent

Question 23

Penetrance

Answer 23

percentage of individuals that express a characteristic given a particular shared genotype

Question 24

Penetrance of Mendelian traits?

Answer 24

100%

Question 25

Incomplete penetrance

Answer 25

not all individuals who have the genotype will express the phenotype

Question 26

Can individuals with incomplete penetrance still pass the trait onto offspring?

Answer 26

YES

Question 27

Congenital

Answer 27

present at birth

Question 28

Are all genetic disease congenital?

Answer 28

no

Question 29

Variable Expression

Answer 29

all individuals with allele express the trait but at different levels of severity (ex: polydactyls); more common with dominant traits versus recessive

Question 30

Inbreeding

Answer 30

mating of individuals with common ancestors

Question 31

Are inbreeding and line breeding the same thing?

Answer 31

yes, they’re the same damn thing

Question 32

Proband

Answer 32

sstarting point for genetic/pedigree analysis of a family, typically the initial individual identified as affected with the condition or trait of interest

Question 33

Reasons to suspect an inherited component?

Answer 33

-multiple affected offpring from same mating
-multiple affected offspring from single paternal/maternal line
-persistence in family despite changed environment