Punnett Squares and Heridity Test Review by chenmeixiu


									Genetics Quiz III Review: Punnett Squares and Heredity
      BI2. c. Students know how random chromosome segregation explains the probability that
       a particular allele will be in a gamete.
      BI2. g. Students know how to predict possible combinations of alleles in a zygote from
       the genetic makeup of the parents.
      BI3. a. Students know how to predict the probable outcome of phenotypes in a genetic
       cross from the genotypes of the parents and mode of inheritance (autosomal or X-linked,
       dominant or recessive).
      BI3. b. Students know the genetic basis for Mendel’s laws of segregation and
       independent assortment.
Directions: Using your coursework and online resources complete the review sheet
Part I. Vocabulary-Matching the terms to their correct definition.
Term:                                        Definition
Homozygote                                   a.) likelihood that a particular event will
Heterozygote                                 b.) allele that is not expressed unless two
                                             copies are present in an organism’s
Dominant                                     c.) specific region of DNA that codes for a
                                             particular protein
Recessive                                    d.) characteristic that is inherited
Allele                                       e.) parental generation
Genes                                        f.) offspring of the parental generation
Trait                                        g.) father of genetics
Offspring                                    h.) TT
Gregor Mendel                                i.) chromosomes that contains genes for
                                             characteristics not directly related to the
                                             sex of the organism
Homozygous dominant                          j.) forms haploid gametes
Homozygous recessive                         k.) the passing of genetic information from
                                             generation to generation
Meiosis                                      l.) the study of heredity patterns and
                                             variation of organisms
Genotype                                     m.) offspring of the F1 generation
Phenotype                                    n.) physical traits determined by an
                                             organism’s genotype
Probability                                  o.) different forms of a gene
Inherit                                      p.) allele that is expressed when two
                                             different alleles are present in an
                                             organism’s genotype.
Genetics                                     q.) allele combination that codes for traits.
Reproductive cells                           r.) the product of a cross or mating
Zygote                                        s.) fertilized egg
Law of Independent Assortment                 t.) tt
Law of Segregation                            u.) Mendel’s 2nd law, stating that allele
                                              pairs separate from one another during
                                              gamete formation
                                              v.) sperm and eggs
                                              w.) having two different alleles
                                              x.) having two of the same alleles
                                              y. Mendel’s 1st law, stating that organisms
                                              inherit two copies of genes, one from each
                                              parents, and organisms donate only one
                                              copy of each gene in their gametes because
                                              the genes separate during gamete

Part II. Answer the following questions below using section 6.2-6.6.

   1. One human parent is homozygous dominant for a trait (TT) while the other parent
      is homozygous recessive for the same trait (tt). Which of the following BEST
      explains why all of the offspring of these parents are heterozygous for the trait
      A. The strongest genetic traits are selected for the offspring.
      B. Each parent contributes one gamete to the zygote.
      C. Genetic information from the parents is combined in a unique way.
      D. The genetic material from each parent has a 50% chance of being in the

   2. A man is heterozygous (Cc) for a recessive trait that causes complete color
      blindness. In order for ANY of this man’s offspring to inherit this trait, the female
      parent MUST have which of the following?
          A. at least one gene for color blindness
          B. one gene for color blindness on a Y chromosome
          C. at least two genes for color blindness
          D. one gene for color blindness on an X chromosome

   3.) Explain Mendel’s two laws in your own words.

   4.) What is the probability of producing a male during fertilization? (Think-Meiosis)
5.) What is the relationship between genotypes and phenotypes?

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