BIOD 210 Genetics Final Exam Questions and Answers (2025 /
2026) (Verified Answers) – Portage Learning
Sometimes two alleles of a certain gene can produce two distinct and independent gene products. In this
case, both alleles are fully expressed and result in __________-. Example?
Codominance; an example of codominance is a protein that is expressed on the surface of red blood cells
known as the M and N glycoproteins.
How many chromosme combinations could two parents pass to a human child?
64 trillion
Where a minimum of gene product is needed to meet a normal phenotypic expression.
Threshold effect
The phenomenon of an intermediate phenotype of the parental strains is known as;
Incomplete or partial dominance
Once in a while, a gene mutation may actually enhance the activity or function of the wild-type gene,
resulting in a ____________.
Gain-of-function mutation.
Total loos of a genes function
Null allele
Often a mutation in a gene causes a partial or total loss of the function of the activity of a particular gene
Loss-of-function mutations.
When a mutation occurs that does not change the function or phenotype of a given gene, it is called a
___________ mutation.
Neutral or silent
Where a single phenotype is affected by more than a single gene.
Gene interaction.
Are simply variations of a given gene
Alleles
For a given trait consists of the two alleles inherited for a particular gene, e.g., DD, dd, or Dd
Genotype
If an individual has two alleles that are the same (DD or dd), they are
1
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Homozygous
, When the individual has two diferent alleles for a given trait, they are classifed as a
Heterozygous
A simple way to visualize monohybrid genetic crosses is by using a
Punnet square
An individual that has the dominant phenotype (tall in this case) but unknown genotype is crossed with a
known homozygous recessive individual (dd)
Testcross
The method used for investigating TWO characteristics simultaneously, a method called a
Dihybrid cross
States that every F1 x F1 crossing will result in this ratio of offspring
Mendel's 9:3:3:1 dihybrid ratio.
States that, during gamete formation, segregating pairs of unit factors (genes) assort independently of
each other
Mendel's Fourth postulate
He probability of two or more independent events occurring simultaneously is equal to the product of
their individual probabilities
Product law of probabilities
. _____________, to easily calculate the probabilities of inheriting any combination of these traits forked-
line method, or branch diagram
Who proposed epigenesis
William Harvey
A concept that is now known to have correctly hypothesized that a fertilized human egg undergoes
specifc developmental events that eventually lead to the formation of a human.
Epigenesis
A concept that a fertilized egg contained a tiny version of a completely developed adults.
Preformation
In preformation, the tiny fully sized adult within the fertilized egg is termed
Homunculus
Who proposed the cell theory?
Matthias Schleiden and Theodor Schwann
2
Proposed that all living organisms were composed of organized structures called cells and that these cells
Page
were derived from identical precursor cells.
2026) (Verified Answers) – Portage Learning
Sometimes two alleles of a certain gene can produce two distinct and independent gene products. In this
case, both alleles are fully expressed and result in __________-. Example?
Codominance; an example of codominance is a protein that is expressed on the surface of red blood cells
known as the M and N glycoproteins.
How many chromosme combinations could two parents pass to a human child?
64 trillion
Where a minimum of gene product is needed to meet a normal phenotypic expression.
Threshold effect
The phenomenon of an intermediate phenotype of the parental strains is known as;
Incomplete or partial dominance
Once in a while, a gene mutation may actually enhance the activity or function of the wild-type gene,
resulting in a ____________.
Gain-of-function mutation.
Total loos of a genes function
Null allele
Often a mutation in a gene causes a partial or total loss of the function of the activity of a particular gene
Loss-of-function mutations.
When a mutation occurs that does not change the function or phenotype of a given gene, it is called a
___________ mutation.
Neutral or silent
Where a single phenotype is affected by more than a single gene.
Gene interaction.
Are simply variations of a given gene
Alleles
For a given trait consists of the two alleles inherited for a particular gene, e.g., DD, dd, or Dd
Genotype
If an individual has two alleles that are the same (DD or dd), they are
1
Page
Homozygous
, When the individual has two diferent alleles for a given trait, they are classifed as a
Heterozygous
A simple way to visualize monohybrid genetic crosses is by using a
Punnet square
An individual that has the dominant phenotype (tall in this case) but unknown genotype is crossed with a
known homozygous recessive individual (dd)
Testcross
The method used for investigating TWO characteristics simultaneously, a method called a
Dihybrid cross
States that every F1 x F1 crossing will result in this ratio of offspring
Mendel's 9:3:3:1 dihybrid ratio.
States that, during gamete formation, segregating pairs of unit factors (genes) assort independently of
each other
Mendel's Fourth postulate
He probability of two or more independent events occurring simultaneously is equal to the product of
their individual probabilities
Product law of probabilities
. _____________, to easily calculate the probabilities of inheriting any combination of these traits forked-
line method, or branch diagram
Who proposed epigenesis
William Harvey
A concept that is now known to have correctly hypothesized that a fertilized human egg undergoes
specifc developmental events that eventually lead to the formation of a human.
Epigenesis
A concept that a fertilized egg contained a tiny version of a completely developed adults.
Preformation
In preformation, the tiny fully sized adult within the fertilized egg is termed
Homunculus
Who proposed the cell theory?
Matthias Schleiden and Theodor Schwann
2
Proposed that all living organisms were composed of organized structures called cells and that these cells
Page
were derived from identical precursor cells.
