Chapter 5: Extensions and Modifications of Basic Principle

Question 1

What type of dominance has the same phenotype regardless of heterozygote or homozygotes?

Answer 1

Complete Dominance

Question 2

What type of dominance has an intermediate phenotype between the phenotypes of the two homozygotes?

Answer 2

Incomplete Dominance

Question 3

What type of dominance has the phenotype of the heterozygote and includes the phenotypes of both homozygotes?

Answer 3

Codominance

Question 4

What is the percentage of individuals having a particular genotype that express the expected phenotype?

Answer 4

penetrance

Question 5

What is the degree to which the character is expressed?

Answer 5

expressivity

Question 6

What does it mean if there are multiple alleles?

Answer 6

for a given locus, more than two alleles are present within a group of individuals

Question 7

What is an example of multiple alleles?

Answer 7

ABO Blood group

Question 8

Gene Interactions

Answer 8

effects of genes at one locus depends on the prescence of genes at other loci

Question 9

What produces novel phenotypes?

Answer 9

gene interactions

Question 10

When one gene masks the effects of another gene at a different locus

Answer 10

Epistasis

Question 11

What is the affect of a lethal allele?

Answer 11

affects the mendalian genotypic and phenotypic ratios in progeny

Question 12

What causes death at an early stage of development?

Answer 12

lethal allele

Question 13

What may not allow some genotypes to appear among progeny?

Answer 13

lethal alleles

Question 14

What ratio does recessive epistasis occur in?

Answer 14

9:3:4 ratio

Question 15

What is an example of Incomplete Pertanance?

Answer 15

polydactyl

Question 16

Incomplete Penetrance

Answer 16

expected phenotype is not shown

Question 17

What is an example of codominance?

Answer 17

AB blood type
-both are able to be expressed

Question 18

What gets masked in recessive epistasis?

Answer 18

recessive gene masks the dominant gene

Question 19

What is the phenotypic ratio in dominant epistasis?

Answer 19

12:3:1

Question 20

What is the phenotypic ratio in duplicate recessive epistasis?

Answer 20

9:7 phenotypic ratio

Question 21

What is a sex influenced characteristic?

Answer 21

phenotype is influenced by gender

Question 22

What is a sex limited characteristic?

Answer 22

both males and females can transmit the trait but only one gender can express it

Question 23

What type of characteristic has the exact same genotype but different presentation based on gender?

Answer 23

sex influenced

Question 24

What is an example of a sex limited trait?

Answer 24

precocious puberty

Question 25

What organelles does cytoplasmic interferance occur mostly in?

Answer 25

mitochondria and chloroplast

Question 26

What is cytoplasmic inheritance?

Answer 26

when progeny recieve differing numbers and types of organelles based on random segregation due to cell division

Question 27

What is the genetic maternal effect?

Answer 27

mom's genotype determines phenotypes of offspring, regardless of offspring's genotype

Question 28

What is the differential expression of genetic material depending on whether it is inherited from the male or female parent?

Answer 28

genomic imprinting

Question 29

What is believed to be caused by methylation and is an example of epigenetics?

Answer 29

genomic imprinting

Question 30

What determines phenotype in genomic imprinting?

Answer 30

parental origin

Question 31

What is the phenomena due to alterations to DNA that do not include changes in base sequence?

Answer 31

epigenetics

Question 32

What does epigenetics affect?

Answer 32

the way in which the DNA sequences are expressed

Question 33

What is a genetic trait that becomes more strongly expressed or is expressed at an earlier stage?

Answer 33

Anticipation

Question 34

What occurs due to the expansion of an unstable region of DNA from generation to generation?

Answer 34

anticiapation

Question 35

What is often caused by trinucleotide repeats?

Answer 35

anticipation

Question 36

What is an allele that is only functional at certain temperatures?

Answer 36

temperature-sensitive alleles

Question 37

What type of characteristics have realtively few phenotypes

Answer 37

discontinuous characteristics

Question 38

Continuous Characteristics

Answer 38

continuous distribution of phenotypes

Question 39

What occurs when genes at many loci interact?

Answer 39

continuous characteristics

Question 40

What is a characteristic encoded by genes at many loci?

Answer 40

polygenic characteristic

Question 41

What is pleiotropy?

Answer 41

when one gene affects multiple characteristics

Question 42

What is an example of pleuotropy?

Answer 42

phenylketonuria

Question 43

What diseases are caused by trinucleotide repeats and anticipation?

Answer 43

Huntington's Disease and Fragile X Syndrome

Question 44

What is an example of a gene that is influenced by environemental effects?

Answer 44

lactose intolerance -does not show unless the person eats a lactose product