Vocabulary
This is the organism's genetic makeup.
genotype
Who is known as the father of genetics?
Gregor Mendel
For each of the genotypes below determine what the phenotype would be.
Brown eyes are dominant to blue eyes.
BB, Bb, bb
Bb - brown eyes
bb - blue eyes
This is an organism's physical appearance.
phenotype
This law of Mendel's states that alleles separate during gamete formation.
In pea plants, tall (T) is dominant over short (t). Cross a homozygous dominant plant with a homozygous recessive plant.
List the possible genotypes of the offspring.
All will be Tt (heterozygous)
This term means having two different alleles.
heterozygous
This law of Mendel's states that different traits are inherited independently.
Law of independent assortment
In guinea pigs, black fur (B) is dominant to white fur (b). Cross two heterozygous guinea pigs.
What percentage of the offspring will have the recessive phenotype?
25%
This term means having two of the same allele.
homozygous
If a trait is dominant, what does that mean?
It will always be physically expressed; it masks the recessive trait
In pea plants, purple flowers (P) are dominant over white flowers (p). Cross Pp × pp.
List the possible genotypes of the offspring in genetics vocabulary (no allele combinations, i.e. do not list aa,etc.).
Which genotypes will cause the dominant phenotype to be expressed physically?
homozygous dominant and heterozygous
(example: AA and Aa)
A species has 6 total chromosomes (3 pairs). Using the formula 2ⁿ (where n = number of chromosome pairs), how many possible gene combinations can be produced from meiosis and fertilization?
64
In mice, gray fur (G) is dominant to white fur (g).
A heterozygous gray mouse is crossed with another heterozygous gray mouse.
What percent of the offspring will be homozygous recessive?
25%