Extensions of Mendelian inheritance 4

Question 1

Mendelain Inheritance

Answer 1

Refers to inheritance patterns that obey the law of segregation (3:1 ratio) & the law of independent assortment (9:3:3:1 ratio)

Question 2

______________ alleles usually carry mutant alleles

Answer 2

Recessive

Question 3

What are the 3 ways dominant mutant alleles exert their effects?

Answer 3

1. Gain-of- function
2. Dominant- negative mutations
3. Haploinsufficiency

Question 4

Gain-of-function mutations

Answer 4

Change the gene so that it gains a new or abnormal function

Question 5

Dominant-negative mutations

Answer 5

Change a protien such that the mutant protein acts against the normal protein

Question 6

Haploinsufficiency

Answer 6

Heterozygote (one with normal allele & mutant allele) exhibits an abnormal or disease phenotype

Ex. Having extra fingers & toes

Question 7

Traits may skip a generation due to ____________ & vary in their expressivity

Answer 7

Incomplete penetrance

Question 8

Incomplete Penetrance

Answer 8

When an allele is expected to cause a certain trait but doesn’t

Question 9

The ____________ may also have an effect on the phenotype

Answer 9

Environment

Question 10

Norm of reaction

Answer 10

The effect of the environment on a phenotype

Question 11

Incomplete dominance

Answer 11

Occurs when two alleles produces a phenotype that is a mix of the two alleles (Ex. Crossing red and white flowers and get a pink flower)

Question 12

Overdominance

Answer 12

When a heterozygote has greater reproductive success than either of the homozygotes

Question 13

In overdominance _____________ is better than _________ because you have a better advantage of survial

Answer 13

Heterozygous is better than homozygous

Question 14

Codominance

Answer 14

When two alleles are both dominant and both traits are expressed in a heterozygous person

(Ex. ABO blood type I^AI^B)

Question 15

Multiple allele

Answer 15

When there is 2 or more alleles

Question 16

What is the universal donor blood type?

Answer 16

Blood type O because its geneotype (ii) is recesive and has no antigens so it can be taken up by either type A or type B blood types

Question 17

What is the universal blood acceptor?

Answer 17

Type AB blood type because its codominant between type A & type B blood type so it can accept A or B blood type

Question 18

How does gender affect the type of traits a person have?

Answer 18

1. Sex-influenced
2. Sex-limited

Question 19

Sex-influenced

Answer 19

When an allele (trait) dominant in one gender but recessive in the other gender (occurs by being heterozygous)

(Ex. Baldness its dominant in men but recessive in females)

Question 20

Sex-limited

Answer 20

Traits that are only for one gender (Ex. Girls have eggs & guys have sperm)

Question 21

Lethal Allele

Answer 21

An allele that has the potential to cause death of an organism (usually inherited recessively)

Question 22

An essential gene

Answer 22

One that must be present for survival

Question 23

Pleitropy

Answer 23

Occurs when the expression of a single gene has two or more affects on its phenotype (when one gene has many traits)

Question 24

What an example of pleiotropy?

Answer 24

Cystic fibrosis because it contains a protein called CFTR which transports Cl^- ions & when that CFTR gene has mutation the CTFR gene can cause thick mucus in lungs, salty sweat on skin , no enzymes in the pancreas, etc

Question 25

More than one gene affects a trait but you only have to look at the single gene where the two traits _____________

Answer 25

Are different

Question 26

Gene Interaction

Answer 26

When two different genes interact to influence the outcome of a trait

Question 27

A gene interaction can exhibit __________ & ____________

Answer 27

Epistasis & Complementation

Question 28

Epistasis

Answer 28

When allels of one gene mask the phenotype of alleles of another gene

Question 29

Complementation

Answer 29

When two recessive parents produce an offspring with a dominant trait

Question 30

_______________ can result from recessive epistatic because the recessive epistatic is recessive if the offspring has any dominant alleles that aren’t mask by the recessive alleles then the dominant alleles is exxpressed

Answer 30

Complementation

Question 31

Due to _________________ loss-of-function alleles may have no effect on the phenotype

Answer 31

Gene redundancy

Question 32

Gene Redundancy

Answer 32

When one gene can compensate for the lost of function in another genes (If one genes losses its function the other gene can make up for both of them)

Question 33

Paralogs

Answer 33

Copies of genes but they aren’t identical (like homologs) (when one gene is missing a paralog may be able to carry on without it)