Pedigree Problems Genetics Worksheet printable pdf download

Pedigree Problems Genetics Worksheet

Pedigree Problems

Tongue rolling

The ability to roll your tongue is caused by a dominant gene (R). If you can't roll your tongue, you are

a non-roller and must be homozygous recessive (rr).

A father cannot roll his tongue but a mother can. Of their four children, one daughter cannot roll her

tongue. The other daughter and both sons can roll their tongues.

1. Complete the pedigree chart including genotype.

Dominant Male

Dominant Female

Recessive Male

Recessive Female

2. What percent of the offspring are homozygous non-rollers?

3. What percent of the offspring are heterozygous rollers?

4. Can the parents produce a homozygous dominant child?

Eye color

The color of your eyes is caused by pigment molecules in the iris, the ring that surrounds the black

pupil in the center. While eye color is actually more complicated than the this, dark eyes (such as

brown or black) is dominant (E) and light eyes (such as blue or grey) is recessive (e).

A father and a mother both have brown eyes. Their two sons have blue eyes and their two daughters

have brown eyes. One daughter carries the gene for blue eyes, the other doesn't.

1. Complete the pedigree chart including genotype.

Dominant Male

Dominant Female

Recessive Male

Recessive Female

2. What percent of the children are homozygous recessive?

3. If one son gets married and all his children have brown eyes, what must the genotype of the his

wife be?

Pedigree Problems Genetics Worksheet