(M) Genetics

First and Last Name

Many farmers prefer cattle without horns because it is safer for their herds. The allele for no horns (N) is dominant to the allele for the presence of horns (n). A farmer mates a male with horns to a heterozygous female without horns. What is the chance that the offspring will have horns? (Hint: you may need to draw a punnett square)

• 3/4
• 1/4
• 1/2

In sheep, the allele for belly fur (A) is dominant to the allele for no belly fur (a). Two heterozygous sheep produce an offspring. What is the percent chance that the offspring will have NO belly fur. (Hint: you may need to do a punnett square)

• 50%
• 25%
• 100%

In tomatoes, tall vines (T) are dominants to dwarf vines (t), and red fruit (R) is dominant to yellow (r). A farmer mates a homozygous tall, red tomato plant (TTRR) with a heterozygous tall, red tomato plant (TtRr). What is the percent chance that the offspring will be dwarf plants with yellow fruit? (Hint: you may need to do a punnett square)

• 50%
• 0%
• 25%

In some chickens, feather color is controlled by codominance. When a black chicken mates with a white chicken, all offspring are covered in both black and white feathers. A farmer mates a black chicken (BB) with a spotted chicken (BW). What are the predicted phenotypes of their offspring? (Hint: you may need to do a punnett square)

• 50% of the offspring will be black, and 50% of the offspring will be spotted
• All of the offspring will have spots.
• 75% of the offspring will be black, and 25% of the offspring will be white.

In snapdragon plants, the gene for red petals (R) is incompletely dominant to the gene for white petals (r). Individuals that are heterozygous (Rr) have pink petals. What type of inheritance is demonstrated here?

• Codominance
• Incomplete Dominance
• Dihybrid Dominance

The pedigree below tracks the presence of dimples through a family's generation. Having dimples is an autosomal dominant trait. If individual III-3 (homozygous dominant) married a woman who was heterozygous for dimples, what is the percent chance their children will have dimples?

• 0%
• 25%
• 100%

The pedigree below tracks the presence of dimples through a family's generation. Having dimples is an autosomal dominant trait. If individual II-1 and II-2 have a fourth child, what is the probability that the child will have dimples?

• 25%
• 50%
• 75%

Alleles of different genes separate independently of one another during gamete formation is best described as:

• Mendel's law of independent assortment
• Mendel's law of allelic frequency
• All of the above

Mendel's law of segregation states that the two alleles for a given trait:

• separate at meiosis
• are eliminated during meiosis
• are tripled during meiosis