Bio 351 Exam 1 QUESTIONS WITH CORRECT ANSWERS| LATEST UPDATE
GUARANTEED SUCCESS
Are Mendel's traits relatively rare? Yes, the environment and multiple alleles affect most of
our genes
Co-dominance situation in which both alleles of a gene contribute to the phenotype of the
organism (ex: human ABO blood groups)
Incomplete dominance the heterozygote has a phenotype intermediate between those of
the two homozygotes
Penetrance the percentage of individuals which show the phenotype expected from the
genotype
Incomplete penetrance not all individuals with a mutant genotype show the mutant
phenotype
Expressivity affected individuals show the phenotype to varying degrees
lethal alleles mutated genes that are capable of causing death
, pleiotropy the ability of a single gene to affect multiple phenotypes
epistasis an allele of one gene can suppress the phenotypic expression of a different gene
What is an example of epistasis? albinism
polygenic inheritance multiple genes controlling a single phenotype - where the effect of
each gene is additive
What is an example of polygenic inheritance? skin color in humans
How do we know if we are looking at mutant alleles of the same gene or mutations in different
genes? genetic complementation
What are some environmental factors that can affect phenotype? sunlight, temperature,
exposure to specific chemicals, toxins, physical contact, etc
deletion where a segment of the chromosome is missing, usually removes multiple genes
duplication where a chromosome segment is copied and repeated
GUARANTEED SUCCESS
Are Mendel's traits relatively rare? Yes, the environment and multiple alleles affect most of
our genes
Co-dominance situation in which both alleles of a gene contribute to the phenotype of the
organism (ex: human ABO blood groups)
Incomplete dominance the heterozygote has a phenotype intermediate between those of
the two homozygotes
Penetrance the percentage of individuals which show the phenotype expected from the
genotype
Incomplete penetrance not all individuals with a mutant genotype show the mutant
phenotype
Expressivity affected individuals show the phenotype to varying degrees
lethal alleles mutated genes that are capable of causing death
, pleiotropy the ability of a single gene to affect multiple phenotypes
epistasis an allele of one gene can suppress the phenotypic expression of a different gene
What is an example of epistasis? albinism
polygenic inheritance multiple genes controlling a single phenotype - where the effect of
each gene is additive
What is an example of polygenic inheritance? skin color in humans
How do we know if we are looking at mutant alleles of the same gene or mutations in different
genes? genetic complementation
What are some environmental factors that can affect phenotype? sunlight, temperature,
exposure to specific chemicals, toxins, physical contact, etc
deletion where a segment of the chromosome is missing, usually removes multiple genes
duplication where a chromosome segment is copied and repeated
