EPISTASIS

Question 1

■ Interaction of nonallelic genes in the formation of the phenotype

Answer 1

Epistasis

Question 2

__________ is a form of gene interaction in which one gene masks the phenotypic expression of another.

Answer 2

Epistasis

Question 3

■The alleles that are masking the effect are called epistatic alleles

Answer 3

Epistatic alleles

Question 4

The alleles whose effect is being masked are called the hypostatic alleles.

Answer 4

hypostatic alleles

Question 5

Epistasis can be described as either ______ or ________

Answer 5

recessive epistasis or dominant epistasis.

Question 6

Occurs when the dominant allele of one gene masks the effects of either allele of the second gene.

Answer 6

Dominant epistasis

Question 7

__________color is controlled by two genes

Answer 7

Squash fruit color

Question 8

__________ gene that can affect the expression of another gene

Answer 8

EPISTATIC

Question 9

Also known as dominant inhibitory epistasis

Answer 9

DOMINANT RECESSIVE INTERACTION

Question 10

Traits that occur in distinct categories

Answer 10

DISCONTINUOUS

Question 11

Distribution of phenotypes in the population varies along a continuum

Answer 11

CONTINUOUS

Question 12

Is an o-methyled anthocyanin responsible for the blue pigments of primula polyanthus plant

Answer 12

MALDVIN

Question 13

Dominant recessive example is

Answer 13

MALDVIN IN PRIMULA FLOWERS

Question 14

More than two alleles and genes control the expression of trait

Answer 14

POLYGENIC INHERITANCE

Question 15

Also known as Duplicate Gene Action

Answer 15

DUPLICATE DOMINANT EPISTASIS

Question 16

Also known as complementary Gene action

Answer 16

Duplicate recessive epistasis

Question 17

Dominant alleles complement each other

Answer 17

DUPLICATE RECESSIVE EPISTASIS

Question 18

Dominant epistasis

Answer 18

Ratio 12:3:1

Question 19

Recessive epistasis

Answer 19

Ratio 9:4:3

Question 20

● If a dominant allele of both gene loci produces
the same phenotype without cumulative effec

Answer 20

DUPLICATE DOMINANT EPISTASIS

Question 21

Both the dominant non allelic alleles, when
present together, give a new phenotype, but
when allowed to express independently, they
give their own phenotypic expression separately

Answer 21

DUPLICATE GENES WITH CUMULATIVE EFFECTS

Question 22

If both gene loci have homozygous recessive
alleles and both of them produce identical
phenotype.

Answer 22

DUPLICATE RECESSIVE EPISTASIS

Question 23

DUPLICATE GENES WITH CUMULATIVE EFFECTS

Answer 23

● The ratio will be 9:6:1

Question 24

The dominant allele, either in homozygous or
heterozygous condition, of one gene and the
homozygous recessive of other gene produce
the same phenotype

Answer 24

● Ratio 13:3

Question 25

The phenomenon in which a single gene
conditions affects several different phenotypical
traits

Answer 25

PLEIOTROPY

Question 25

a is an abnormality
in the expression of a single mutated
each BB gene which produces
numerous consequences throughout the
body

Answer 25

SICKLE CELL ANEMIA

Question 26

It is caused by a defect in the
phenylalanine hydroxylase enzyme. So
the gene responsible for that is mutated

Answer 26

● Phenylketonuria

Question 27

○ Lack of thyroxine from birth
○ Or before birth
○ Could be lack of thyroid gland
○ Or lack of iodine in mother
○ Severe and irreparable mental defects
○ Stunted growth
○ Reduced growth and function of many
organs

Answer 27

CRETINISM

Question 28

○ genes with at least one allele that one
present in the genotype of an individual,
causes death.
○ it can be dominant or recessive lethal

Answer 28

● Lethal Genes

Question 29

○ The perfect example is the Huntingdon’s
disease. If the father is recessive to
Huntington’s disease and the mother is
heterozygous you will produce 50
percent affected child and 50 percent
normal child.

Answer 29

● Dominant Lethal Genes

Question 30

Low levels of thyroid hormone in early years life

Answer 30

CRETINISM

Question 31

Dwarfism

Answer 31

ACHONDROPLASIA

Question 32

Example of Recessive lethal genes

Answer 32

Manx cats tail less

Question 33

CFTR means

Answer 33

Cystic Fibrosis Transmembrane Receptor

Question 34

CFTR gene mutation

Answer 34

Cystic Fibrosis