Grade 11 University Biology - Unit 2 Genetics by gM9zk03g

VIEWS: 112 PAGES: 3

									                              Grade 11 University Biology - Unit 2 Genetics
                           Mendel –Inheritance Terminology
                                    Chapter 5.1 – Pages 202-207
Mendel’s Laws of Heredity
       1. Each parent contributes one allele during cross-feritilzation
       2. The dominant allele is always expressed when both the dominant and recessive alleles are
           present
       3. Each pair of alleles segregates duirng the formation of the sex cells (meiosis)

Terminology
Fill in the definition for the following terms AND provide a description in your own words or with an
alternative form (e.g., example, Punnett square, diagram, picture). Use you textbook and the Internet.
        Term                                            Definition

Trait

True Breeding

P Generation

F1 Generation

F2 Generation

Dominant

Recessive

Genotype

Phenotype

Homozygous

Heterozygous

Test Cross

Punnett
Square

Monohybrid
Cross

Dihybrid Cross

Purebred
Stock
One Factor Cross – Crosses involving only one trait
Use the information in this table to answer the questions about genotypes and phenotypes
     Trait          Dominant         Recessive

Pod shape         Smooth (N)      Constricted (n)

Pod colour        Green (G)       Yellow (g)

Plant height      Tall (T)        Short (t)

Problem 1.
A plant that is heterozygous for green pods is crossed with a plant that has yellow pods. What are the
possible genotypes and phenotypes ratios of the offspring from the cross?

        Step 1. Determine the parent genotypes
                 Green pod parent (heterzygous) = Gg
                 Yellow pod parent (homozygous recessive) = gg

        Step 2. Determime the possible gametes from each parent
                 Green Gg = g and G
                 Yellow gg = g and g

        Step 3. Draw a “four-square Punnett square and place the gametes for one parent along the top
        and one parent along the side

                                          g               g

                             G

                             g



        Step 4. Complete the Punnett square by writing down all the allele combinations from the cross
                                          g               g

                             G           Gg              Gg

                             g           gg              gg

        Step 5. Determine percentage of each genotype
                 Green Gg = 50%
                 Yellow gg = 50%

        Step 6. Determine the phenotypes for each offspring
                 Green is Gg
                 Yellow is gg
Problem 2.
You are given the number of offspring of two different phenotypes. You have 5,472 SMOOTH POD peas
and 1,850 CONSTRICTED POD peas. Determine the genotypes of the parents.


If you determine that both partents were round and heterozygous dominant (Nn), you get it.


Problem 3.
You cross a homozygous tall plant with a short plant.
        What are the correct genotypes in this problem?
        Correctly name the genotypes
        How many short plants will be produced? Explain your answer.

Problem 4.
You cross a heterozygous tall plant with a short plant.
        What are the correct genotypes in this problem?
        Correctly name the genotypes
        How many short plants will be produced? Explain your answer.


Punnett square practice for one factor crosses.
For each of the following probems, complete a Punnett square and fill in the information for the offspring

        1. Nn X NN
            Genotypes of offspring
            Genotype ratio
            Phenotype ratio




        2. Gg X gg
            Genotypes of offspring
            Genotype ratio
            Phenotype ratio




        3. Tt X Tt
            Genotypes of offspring
            Genotype ratio
            Phenotype ratio



        4. Cross between two plants
           that are heterozygous for
           green coloured pods
            Genotypes of offspring
            Genotype ratio
            Phenotype ratio

								
To top