Genetics Exam Review

The letters on the TOP AND SIDE of a punnett square represent ______________.

• The combination of alleles in offspring.
• The possible alleles given by the parents following meiosis.
• The genotype and phenotype of offspring.
• The results of genetic mutations in offspring.

What is the predicted percentage of homozygous recessive offspring in this cross?

• 0%

• 25%

• 50%

• 75%

This type of inheritance pattern shows BOTH traits in possible offspring

• complete dominance
• incomplete dominance
• co-dominance
• dominant pattern

The dominant trait in this punnett square is

• yellow pea seeds
• green pea seeds
• there is no dominant seed

this image is an example of

• codominance
• dominance
• incomplete dominance

A breed of chicken shows codominance for feather color. One allele codes for black feathers, another codes for white feathers. The feathers of heterozygous chickens of this breed will be:

• all black
• all white
• all gray
• speckled black and white

In some carnations, flower color exhibits codominance.  Identify the correct genotypes for red, white, and speckled carnations.

• Red = RR, white = rr, speckled = Rr
• Red = RR, white = WW, speckled = rw
• Red = RR, white = ww, Speckled = Rw
• Red = RR, white = WW, speckled = RW

Look at this cross: X^BX^b x X^BY

What proportion of the male children are colorblind?

• 100%

• 75%

• 50%

• 25%

H= normal blood clotting

h=hemophilia

X^HX^h x X^HY

What is the probability that any of their offspring will have hemophilia?

• 4/4

• 3/4

• 2/4

• 1/4

Males are more likely to suffer from a sex-linked disease or disorder because

• males are the weaker sex
• males have less DNA
• males have 1 X chromosome, so the disorder is more likely to be expressed