Download Punnett Practice

Punnett Practice
For each of the problems below, show the punnett square.
1.
In silkworms a single gene determines the color of the cocoon. The yellow cocoon allele is dominant. It
is indicated by "C". The white allele is recessive, and indicated by "c". Complete the following Punnett Square
assuming a homozygous dominant male (CC) fertilizes a homozygous recessive female (cc).
2.
The length of fur in guinea pigs is controlled by a single gene. The dominant allele "F" produces short
fur. The recessive allele "f" produces long fur. Complete the following Punnett Square assuming a heterozygous
male (Ff) fertilizes a homozygous recessive female (ff).
3.
In mice a single gene determines the color of the eyes. The black eyes allele is dominant. It is indicated
by "E". The red allele is recessive, and indicated by "e". Complete the following Punnett Square assuming a
heterozygous male (Ee) fertilizes a heterozygous female (Ee).
4.
In race horses, black hair (F) and a trotting gait (G) are dominant traits. Recessive traits are chestnut hair
(f) and a pacing gait (g). The genes for hair color and gait are on two differnet chromosomes. Use the Punnett
Square below to determine the possible offspring from a cross between two heterozygous black trotters (FfGg).
5.
In fruit flies the allele for normal size wings (W) is dominant over the allele for vestigial wings (w). The
allele for normal size eyes (E) is dominant over the allele for small eyes (e). The genes for wing size and eye
size are on different chromosomes. Use the Punnett Square below to predict the results of a cross between an
individual heterozygous for both traits and one that is homozygous recessive for both traits.
6. In certain trees, smooth bark is dominant over wrinkled. Cross two trees that are heterozygous for smooth
bark. If there are 100 offspring produced, how many will have wrinkled bark?
7. In Mountain Boomers, the genes for length of tail exhibit "incomplete" dominance. Use a Punnett Square to
predict the result of a cross between a homozygous Long-tailed and a homozygous Short-tailed Mountain
Boomer. What do the offspring look like?
8. In certain bacteria, an oval shape is dominant over round and thick cell walls are dominant over thin. Cross a
heterozygous oval, thick cell walled bacteria with a round, thin cell walled bacteria. Describe the phenotype of
the offspring.
9. In guinea pigs, black coat color is dominant over white, short hair is dominant over long, and rough coat is
dominant over smooth. A cross between a homozygous black, short-haired, rough coat guinea pig and a
homozygous white, long-haired, smooth coat guinea pig. What do the offspring look like?
10. Short Hair(L) is dominant over long hair(l) in rabbits. The gene for spotted coat color (S) is dominant over
the allele for solid color (s). Two dihybrid rabbits are mated. What phenotypes are expected? Show the punnett
square.