Genetics (Mendelian Ratio's)

Front 1

Codominance

Back 1

condition in which the phenotypic effects of a gene's alleles are fully and simultaneously expressed in a heterozygote

Front 2

Blood types are an example of what type of dominance?

Back 2

Codominance

Front 3

What is characterized in humans by an antigen called a glycoprotein, found on the surface of RBC?

Back 3

MN blood group

Front 4

Codominance has what genotypic ratio?

Back 4

1:2:1

Front 5

Incomplete Dominance

Back 5

expression of heterozygous phenotype that is distinct from and often intermediate to that of either parent

Front 6

pink flowers as an intermediate of a white parent and a red parent is an example of what?

Back 6

Incomplete dominance

Front 7

what is the ratio for incomplete dominance?

Back 7

1:2:1

Front 8

In the ABO system, which antigens are codominant and which is/are recessive?

Back 8

A and B are codominant
O is recessive to A and B

Front 9

Bombay phenotype is caused by? mechanically

Back 9

The H substance being incompletely formed

Front 10

Bombay phenotype is causes by? genetically

Back 10

having to hh alleles that inhibit antigens from binding to the cell surface

Front 11

recessive lethal alleles

Back 11

recessive, lethal when homozygous recessive

Front 12

dominant lethal alleles

Back 12

lethal with just one copy
e.g. huntingtons disease

Front 13

Combination of two gene pairs with two modes of inheritance gives what ratio?

Back 13

3:6:3:1:2:1

Front 14

gene interaction

Back 14

product of novel phenotypes by the interaction of alleles of genes.

Front 15

epistasis

Back 15

occurs when the expression of one gene or gene pair masks or modifies the expression of another gene or gene pair

Front 16

When is the ratio 3:6:3:4 ratio expected?

first type of epistasis

Back 16

When studying a single character, a ratio that is expressed in 16 parts suggests that two gene pairs are interacting during the expression of the phenotype under construction

Front 17

When is the the ratio 12:3:1 expected?

second type of epistatis

Back 17

when a dominant allele at one genetic locus masks the expression of the alleles at a second locus.

Front 18

What type of epistasis is this?

A dominant A allele results in white fruit color regardless of the genotype at the second locus,B. In the absence of the dominant A allele (the aa genotype), BB or Bb results in yellow color, while bb results in green color.

Back 18

Second type 12:3:1

Front 19

Define the first type of epistasis

Back 19

The homozygous presence of a recessive allele prevents or overrides the expression of other alleles at a second locus (or several loci)

Front 20

What type of epistasis is this?

In the Bombay phenotype, the homozygous condition at one locus masks the expression of the second locus. hh masks the expression of the A and B alleles, therefore, causing type O blood

Back 20

first type of epistasis

3:6:3:4

Front 21

the homozygous condition of either recessive allele masks the expression of the dominant allele at the other locus

Back 21

third type of epistatis. 9:7

Front 22

What type of epistasis is th

Two true-breeding plants are crossed. Purple is dominant and white is recessive, if you have a homozygous condition for either set of alleles you'll get white flowers (recessive)

Back 22

3rd type of epistasis

Front 23

Novel Phenotypes

9:6:1

Back 23

To get the 9- must have a dominant allele in each allele pair.

To get 6- must have a dominant allele in one gene pair.

To get 1- must have no dominant alleles.

Front 24

Complementation anaylsis

Back 24

allows us to determine whether two such mutations are in the same gene- that is, whether they are alleles, or whether they represent mutations in seperate genes.
"are 2 mutations that yield similar phenotypes present in the same gene or two different genes?"

Front 25

complementation group

Back 25

all mutations determined to be present in any single gene