Chapter 14: Mendel and the Gene Idea
Supplemental Instruction
Iowa State University / Leader: / Jessica
Course: / Bio 211 (5)
Instructor: / Dr. Holscher
Date: / 10/25
  1. What is a monohybrid cross?
  2. What is a dihybrid cross?
  3. What does it require for a dominant trait to be expressed?
  4. What does it require for a recessive trait to be expressed?
  5. Give examples of the following (using big A’s and little a’s):

Homozygous recessive:

Homozygous dominant:

Heterozygous:

  1. Match the generation abbreviation to the proper step:

True-breeding plant generation that Mendel crossed first ______

First set of offspring ______

Second set of offspring that Mendel allowed to self-pollinate ______

  1. True or False: Linkage and sex-linkage are the same thing.
  1. Two parents have a child. One parent is heterozygous for the trait, and one has blue eyes. Blue eye color is a recessive trait. What is the probability that their child will have blue eyes? What is the probability that their child will be a carrier for blue eyes? (hint: Punnett’s square!)
  1. In turtles, (pretend that) smooth shells are dominant over bumpy shells. If one parent turtle is heterozygous and all of the offspring have smooth shells, what was the genotype of the other parent? What was the phenotype of the other parent? (hint: Punnett’s square!)
    genotype parent:
    genotype other parent:

Phenotype other parent:

  1. You have a cat with short fur (ff) and green eyes (Gg).

What type of cross would you perform if this cat were to mate?

How many different types of gametes can your cat produce? What are they?

  1. Your cat decides to mate with a cat with long fur (Ff) and green eyes (Gg). How many different types of gametes can this cat produce? What are they?
  1. What is the equation to find recombination frequency?
  1. In a particular animal species, a long tail (T) is dominant to a short tail (t), and black hair (B) is dominant to brown hair (b). When a TtBb female is mated with a ttbb male, the observed distribution of offspring is as follows: 958 offspring with a long tail and black hair, 124 offspring with a long tail and brown hair, 115 offspring with a short tail and black hair, and 962 offspring with a short tail and brown hair. Based on these offspring, what is the approximate recombination frequency?
  1. Describe the three different types of dominance:

complete:

codominance:

incomplete dominance:

  1. Who was the first scientist to prove that specific genes are located on specific chromosomes?
  1. A plant that has the genotype Aabbcc
  1. Is triploid
  2. Is homozygous at two loci
  3. Is heterozygous at two loci
  4. has dominant alleles at three loci
  1. Cystic Fibrosis

NN / Nn (carrier)
Nn (carrier) / nn (CF)

With the outcome above, what were the alleles of both parents?

___ % chance their child would be a carrier.

___% chance their child would have Cystic Fibrosis.

___% chance their child wouldn’t be a carrier or have Cystic Fibrosis.

  1. If 2n=12 and crossing over does not occur, how many possible combination of daughter cells could result from meiosis?
  1. When a single gene influences many traits it is said to be ______.
  1. The most common phenotype in population is referred to as ______.