Name period date assigned date due date returned ollow instructions 1-4. ross 1. Place the parents genotypes in the Punnett Square and fill in the offspring s genotypes. Parent 2 Parent 1 Genotype Results of ross Phenotype Was parent 1 homozygous (TT or tt) or heterozygous (Tt)? Was parent 2 homozygous (TT or tt) or heterozygous (Tt)? What percent of the offspring were homozygous dominant (TT)? What percent of the offspring were homozygous recessive (tt)? What percent of the offspring were heterozygous (Tt)? What percent of the offspring were purple, tall and round (TT or Tt)? What percent of the offspring were white, short, and wrinkled (tt)? 1
ross 2: ollow instructions 5-7. Parent 2 Genotype Results of ross Phenotype Parent 1 Was parent 1 homozygous or heterozygous? Was parent 2 homozygous or heterozygous? What percent of the offspring were homozygous dominant? What percent of the offspring were homozygous recessive? What percent of the offspring were heterozygous? What percent of the offspring were purple, tall and round? What percent of the offspring were white, short, and wrinkled? ross 3: Repeat the process. Parent 2 Genotype Results of ross Phenotype Parent 1 Was parent 1 homozygous or heterozygous? Was parent 2 homozygous or heterozygous? What percent of the offspring were homozygous dominant? What percent of the offspring were homozygous recessive? What percent of the offspring were heterozygous? What percent of the offspring were purple, tall and round? What percent of the offspring were white, short, and wrinkled? 2
21. What genotypes would the parents need to have to produce ONLY purple, tall and round? 22. What genotypes would the parents need to have to produce ONLY white, short and wrinkled? 23 our puppies in the same litter have different hair color than the mother dog. Which of the following process is responsible for the variety of hair color in this litter? 24 What percentage of offspring from a Tt x Tt cross would be tt? 25% G 50% A asexual reproduction H 100% B binary fission 0% regeneration D sexual reproduction 25 An offspring inherited a dominant allele from one parent and a recessive allele from the other parent for the same trait. Which of the following is a possible explanation for what will be exhibited by the offspring for that trait? The offspring will exhibit the recessive trait with the dominant trait being masked. G The offspring will exhibit the dominant trait with the recessive trait being masked. H The offspring will not exhibit that trait because the dominant and recessive traits he received will each mask the other. The offspring will combine the recessive allele with the dominant allele and exhibit an entirely new trait. 3
USE THE OLLOWING INORMATION TO ANSWER THE QUESTIONS ON THIS PAGE. In humans, eye color and hair color are controlled by several genes. Assume for the following questions that each is controlled by only one. or eye color, brown (B) is dominant over blue (b) and for hair color, black (H) is dominant over blonde (h). A male with blue eyes produces offspring with a female that has brown eyes. 26 Which of the following represents possible parental genotypes for eye color? 28 The genotypes for hair color for the parents are: ather hh Mother A ather: bb, Mother: bb B ather: bb, Mother: Bb ather: BB, Mother: Bb D ather: Bb, Mother: BB Which of the following Punnett squares correctly represents the possible genotypes for hair color for the offspring? A B hh hh 27 What is NOT a possible genotype for eye color for the offspring? hh Bb G BB D H bb There is not enough information 4
A dog breeder has begun to raise Labrador retrievers. So far, she hasn t been able to predict the color of the puppies that she breeds. She does not know that dark fur (D) is dominant over yellow fur (d). When the breeder crossed a yellow Lab female with a dark furred male, she expected half of the puppies to be yellow and half to be dark. However, in a litter of eight puppies, all had dark fur. The breeder next crossed the same yellow female with a different dark male. This time, half the puppies were yellow and half were dark. 29 Which letter represents the most probable genotype of the second male? Dd G DD H DO dd 30 How can the woman breed a litter of all yellow puppies? A By making sure that either the mother or the father is yellow B By making sure that both the mother and father are yellow By making sure that at least one of the grandparents are yellow D She cannot breed for a yellow litter because yellow fur is recessive. 5
31 A student hypothesizes that green pod color in pea plants is dominant and yellow pod color is recessive. Which observation would disprove this hypothesis? Two plants with green pods produce an offspring with green pods. G Two plants with yellow pods produce an offspring with green pods. H Two plants with green pods produce an offspring with yellow pods. Two plants with yellow pods produce an offspring with yellow pods. 32 The work of Gregor Mendel was based on his discovery that hereditary information for two different forms of a trait can coexist in one individual. He recognized that one form of the trait can mask the expression of the other. This principle is known as - A the law of genotypes 33 Which of these choices is the definition of allele? A the form of a gene that is expressed B one of the alternative forms of a gene the combination of genes for a specific trait B the law of dominance the law of separation D the complete genetic makeup of a living thing D the law of sorting 6
34 A scientist crosses a rabbit with short fur and a rabbit with long fur. Which of these outcomes would show that the trait for fur length is an example of incomplete dominance? A All the offspring have no fur. B All of the offspring have long fur. 35 A snapdragon plant with red flowers is crossed with a snapdragon plant with white flowers. The offspring have red and white petals. Which of these conditions does this cross illustrate? A codominance B non-dominance All the offspring have short fur. D All the offspring have medium-length fur. complete dominance D incomplete dominance 36 Examine the Punnett square below. 37 Look at the diagram below. A a B B A? Aa B BB BB a Aa aa b Bb Bb Which of the following choices gives the alleles of the parents shown here? Which of these choices should be placed in the box with the question mark? A AA A BB and BB B Aa B BB and Bb aa Bb and Bb D AA or aa D Bb and bb 7