Biology 102 Exam 2 WSU Carloye
Gene vs Allele - CORRECT ANSWER-Gene: A section of DNA that controls a
certain trait. Example: Eye color.
Allele: A specific variation of a gene.
Example: Having blue eyes.
Dominant vs Recessive - CORRECT ANSWER-Dominant: Determines the
expression of a trait (visually).
Example: Brown eyes, dark hair.
Recessive: Much less likely to determine the expression of a trait.
Example: Blue eyes, blonde hair.
Homozygous vs Heterozygous - CORRECT ANSWER-Homozygous: A
homozygous trait is when two of the same kind of alleles combine to form a trait.
Example: When two tall people have a tall child. Both parents had the same
allele and gave it to their child to create a trait.
Heterozygous: When two different alleles combine to form a trait.
Example: A tall person and a short person have a child who is short. The short
allele is dominant so the child grew up to be short.
Genotype vs Phenotype - CORRECT ANSWER-Genotype: The set of genes that
an organism carries.
Phenotype: All of an organisms observable characteristics.
"True-Breeding" - CORRECT ANSWER-When parents product offspring that will
carry the same phenotype. This means that the parents are homozygous for
every trait.
Example: Two purebred labs having purebred puppies with the same traits as
them.
When doing genetic crosses, what does it mean to be a "carrier" of a trait? -
CORRECT ANSWER-A carrier is someone who has (carries) a recessive allele
, for a genetic trait or mutation but doesn't display that trait physically or show
symptoms of the trait.
Example: Sickle cell anemia.
Which process gives rise to gametes - mitosis or meiosis or both? - CORRECT
ANSWER-Meiosis gives rise to gametes but mitosis does not.
Define "Polygeny" - CORRECT ANSWER-The theory that humans evolve from
several independent pairs of ancestors.
Define "Epistasis" - CORRECT ANSWER-The idea that traits are often produced
through a series of steps. If one step fails, then you don't get to the end result.
How does polygeny give rise to such a wide array of skin colors? - CORRECT
ANSWER-Each dominant allele contributes to 1 increment of pigment. Recessive
allele contributes to no pigment.
Example: Someone with aabbcc would have very light skin, and someone with
AABBCC would have very dark skin.
Explain how two blue-eyed parents can have a brown-eyed child. Discuss the
two genes involved, what role each plays in creating the pigment of the eyes and
what combination of alleles gives rise to blue and brown-eyed phenotypes. -
CORRECT ANSWER-If the parents are both carriers of the brown eyed gene, it
is possible to have a brown eyed baby. A functional gene has pigment, while a
non-functional gene has no pigment.
Define "sex-linked". - CORRECT ANSWER-A trait associated with a gene that is
only carried by the male or female parent.
What combination of chromosomes is associated with the sex of an individual in
humans? - CORRECT ANSWER-A female has two X chromosomes (XX) and a
male has an X and a Y chromosome (XY).
What gene determines the sex of a developing embryo? - CORRECT
ANSWER-The Y-chromosome carries the SRY gene, which is the "Sex
Determining Region of the Y". The SRY gene stimulates testosterone production
Gene vs Allele - CORRECT ANSWER-Gene: A section of DNA that controls a
certain trait. Example: Eye color.
Allele: A specific variation of a gene.
Example: Having blue eyes.
Dominant vs Recessive - CORRECT ANSWER-Dominant: Determines the
expression of a trait (visually).
Example: Brown eyes, dark hair.
Recessive: Much less likely to determine the expression of a trait.
Example: Blue eyes, blonde hair.
Homozygous vs Heterozygous - CORRECT ANSWER-Homozygous: A
homozygous trait is when two of the same kind of alleles combine to form a trait.
Example: When two tall people have a tall child. Both parents had the same
allele and gave it to their child to create a trait.
Heterozygous: When two different alleles combine to form a trait.
Example: A tall person and a short person have a child who is short. The short
allele is dominant so the child grew up to be short.
Genotype vs Phenotype - CORRECT ANSWER-Genotype: The set of genes that
an organism carries.
Phenotype: All of an organisms observable characteristics.
"True-Breeding" - CORRECT ANSWER-When parents product offspring that will
carry the same phenotype. This means that the parents are homozygous for
every trait.
Example: Two purebred labs having purebred puppies with the same traits as
them.
When doing genetic crosses, what does it mean to be a "carrier" of a trait? -
CORRECT ANSWER-A carrier is someone who has (carries) a recessive allele
, for a genetic trait or mutation but doesn't display that trait physically or show
symptoms of the trait.
Example: Sickle cell anemia.
Which process gives rise to gametes - mitosis or meiosis or both? - CORRECT
ANSWER-Meiosis gives rise to gametes but mitosis does not.
Define "Polygeny" - CORRECT ANSWER-The theory that humans evolve from
several independent pairs of ancestors.
Define "Epistasis" - CORRECT ANSWER-The idea that traits are often produced
through a series of steps. If one step fails, then you don't get to the end result.
How does polygeny give rise to such a wide array of skin colors? - CORRECT
ANSWER-Each dominant allele contributes to 1 increment of pigment. Recessive
allele contributes to no pigment.
Example: Someone with aabbcc would have very light skin, and someone with
AABBCC would have very dark skin.
Explain how two blue-eyed parents can have a brown-eyed child. Discuss the
two genes involved, what role each plays in creating the pigment of the eyes and
what combination of alleles gives rise to blue and brown-eyed phenotypes. -
CORRECT ANSWER-If the parents are both carriers of the brown eyed gene, it
is possible to have a brown eyed baby. A functional gene has pigment, while a
non-functional gene has no pigment.
Define "sex-linked". - CORRECT ANSWER-A trait associated with a gene that is
only carried by the male or female parent.
What combination of chromosomes is associated with the sex of an individual in
humans? - CORRECT ANSWER-A female has two X chromosomes (XX) and a
male has an X and a Y chromosome (XY).
What gene determines the sex of a developing embryo? - CORRECT
ANSWER-The Y-chromosome carries the SRY gene, which is the "Sex
Determining Region of the Y". The SRY gene stimulates testosterone production
