# Punnett Square Practice Problems

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Punnett Square Practice Problems
#1 monohybrid cross If you breed two pea plants together, and one has inflated pods (Ii) and the other has constricted pods (ii), what are the possible zygotes (seeds) and at what probabilities? Use a Punnett square to answer the problem. Show your work and circle your final answer (percentages). #2 Codominance Blood Type is either A, B, or o. A and B are both dominant, and o means that you don’t have either. If your dad is Ao, and your mom is AB, what are your possible blood types and at what percentages? Use a Punnett square to solve.

#3 Sex linked traits Baldness is recessive (f) over having full hair (F) and this gene is sex linked on the X chromosome. Suzy has a bald father and a normal mother so she is XF/Xf. Her husband Jim is bald so he is Xf / Y. How many of their boys will be bald? How many girls will be bald? How many of each will not be bald but carriers? #4 Incomplete Dominance Cow color can be white Cw or black CB. Mixing white and black makes spotted cows Cw CB. A black cow and a spotted cow mate. What offspring could they have at what possibilities?

#1 Your uncle is a dwarf and has brown eyes. His dad was a dwarf and his mom was not, and his dad has blue eyes, but his mom had brown eyes, so his genotype is (DdBb). Although not related, your aunt is also a dwarf with brown eyes with the same genotype (DdBb). They are planning on having a baby. What possible types of kids could they have, and at what probability? D= Dwarfism d= normal height B= brown eyes b= blue eyes #2 A couple wants to have kids but they want to know how there kids will turn out. The dad has brown hair (Bb) and good vision (Vv). The mom also has brown hair (Bb) but has bad vision (vv). What are the possible traits of the children, and what are the probabilities (in percents) of each occurring?

3. In rabbits, the coat color black dominant (B) over brown (b)
3. In rabbits, the coat color black dominant (B) over brown (b). Short hair is dominant (S) over long (s). In a cross between a black short-haired male (BbSS) and a brown short-haired female (bbSs), what possible children could be born, and at what probabilities? 4. In the species of Rabbit above, a yellow rabbit and a red rabbit mate. 25% of their offspring are white. What are the genotypes of the parents? 5. A tall, yellow-seeded pea plant heterozygous for height and seed color (TtYy) is crossed with a tall, green-seeded pea plant that is heterozygous for height but homozygous recessive for seed color (Ttyy). If 80 offspring are produced, how many are expected to be tall and have yellow seeds?