Lesson 5.3 Teacher’s Guide

Genetics: Monohybrid Cross

Standards:

Benchmarks:

Tentative Timeline:

Genetics

Lesson 5.3

Monohybrid Cross

Of all the rocks upon which we build our lives, we are reminded today that family is the most important. - Barack Obama

 Figure 5.8: Barack Obama Family Portrait 2011 by Pete Souza, official White House photographer / Public Domain 

Everything that makes us unique individuals, male or female, or just human, is genetic. We get our genetics or genes from our biological parents. The 23 chromosomes from our mother and the 23 chromosomes from our father combine to create us. There is no difference between how the Obama Family genetics or your family’s genetics are determined. This lesson will explore the different ways your genetics are determined.

Lesson 5.3 Learning Targets 

Below are the learning targets you are expected to master for this lesson. Next to each learning target is a number 1-4. As a pre-assessment, before the lesson begins, please circle the number that describes your current understanding of the learning target. Before the formative assessment, please draw a triangle around the number that describes your understanding of the learning target. Before the summative assessment, please draw a square around the number that describes your understanding of the learning target.

Learning Targets for Lesson 5.3

My self-assessment

1 - I have never seen this learning target before.

2 - I have seen this learning target, but I don't know what it means.

3 - I have seen this learning target, and I think I know what it means

4 - I can explain this learning target to another student.

I can define and use the terms phenotype, genotype, allele, homozygous and heterozygous.

1

2

3

4

I can complete and explain a genetics simple dominance problem using a Punnett square.

1

2

3

4

I can complete and explain a genetics incomplete and codominance problem using a Punnett square.

1

2

3

4

I can complete and explain a genetics blood typing problem using a Punnett square.

1

2

3

4

I can complete and explain a sex-linked genetics problem using a Punnett square.

1

2

3

4

Lesson 5.3 Vocabulary

Below are the key vocabulary terms you are expected to master for this lesson. Under each learning target is a number 1-4. As a pre-assessment, before the lesson begins, please circle the number that describes your current understanding of the terms. Before the formative assessment, please draw a triangle around the number that describes your understanding of the terms. Before the summative assessment, please draw a square around the number that describes your understanding of the terms.

As you go through the lesson, write a definition (in your own words) in the middle column, and complete the Extra Practice column according to the key.

Term

1 - I have never seen this term before.

2 - I have seen this term, but I don't know what it means.

3 - I have seen this term, and I think I know what it means

4 - I can explain this term and its meaning to another student.

Definition

Extra Practice

Prefixes and Suffixes: Find out what the word parts mean, then put them together

Sentence: Use the term properly in a complete sentence

Sketch: Draw a sketch of the term

Examples: Give examples of the term

On Your Own: Choose your own option or write an alternative definition using your prior knowledge.

Gene

1            2            3            4

SENTENCE:

Allele

 

1            2            3            4

 

FILL IN THE BLANK:

In organisms that reproduce sexually, ______ alleles for each gene are inherited, one from each parent.

Punnett Square

1            2            3            4

SKETCH:

Genotype

 

1            2            3            4

 

EXAMPLE(S):

 

Phenotype

1            2            3            4

 

EXAMPLE(S):

 

Homozygous (pure)

 

1            2            3            4

 

EXAMPLE(S):

Heterozygous (hybrid)

 

1            2        3            4

 

EXAMPLE(S):

Monohybrid cross

 

1            2            3            4

 

SKETCH: Please draw a Punnett square to make a monohybrid cross between two parents with the following genotypes: TT x tt

 

Lesson 5.3.1: Punnett Squares

5.3.1P: Punnett Square Process Practice. 

Lesson 5.3.2: SImple Dominance Traits

5.3.2P Simple dominance practice.

Lesson 5.3.3: Incomplete and Codominance Traits

5.3.3P incomplete and codominance practice.

Lesson 5.3.4: Blood Typing Traits

5.3.4P blood typing practice.

Lesson 5.3.5: Sex-linked

5.3.5P Sex-Linked Practice.

Lesson 5.3 Formative Assessment

1. Which sentence correctly shows the relationship between the words; gene, allele and chromosome?

        a. chromosomes are on genes which have alleles

        b. alleles are the options for genes and genes are found on chromosomes

        c. genes and chromosomes can be found on alleles

        d. genes are the chromosomes and alleles can be found on them

Match the following definitions to correct word.

____ 2. a genotype in which the person has two of the same allele

____ 3. the more powerful trait, shown with a capital letter

____ 4. a genotype in which the person has two different alleles

____ 5. the physical description of a trait or allele

____ 6. the letters used to describe a trait

  1. Phenotype
  2. Genotype
  3. Allele
  4. Homozygous
  5. Heterozygous
  6. Dominant
  7. Recessive

7. What is a Punnett square?

        a. a tool used to measure the angle of a square

        b. a genetic tool used to help predict the results of a cross

        c. a genetic tool used to show the actual results of a cross

        d. a game played at recess

8. Which of the following Punnett squares has not been done correctly.

a.

b.

c.

d.

        

9. Snapdragon flowers come in three different colors red, blue and purple. Is this an example of an incomplete dominant or codominant trait?

        a. incomplete dominant

        b. codominant

        c. neither

        d. both

10. Sex-linked traits are attached to the _____ chromosome.

        a. Y

        b. V

        c. Z

        d. X

Lesson 5.3 Formative Assessment Key

1. Which sentence correctly shows the relationship between the words; gene, allele and chromosome?

        a. chromosomes are on genes which have alleles

        b. alleles are the options for genes and genes are found on chromosomes

        c. genes and chromosomes can be found on alleles

        d. genes are the chromosomes and alleles can be found on them

Match the following definitions to correct word.

__D__ 2. a genotype in which the person has two of the same allele

__F__ 3. the more powerful trait, shown with a capital letter

__E__ 4. a genotype in which the person has two different alleles

__A__ 5. the physical description of a trait or allele

__B__ 6. the letters used to describe a trait

  1. Phenotype
  2. Genotype
  3. Allele
  4. Homozygous
  5. Heterozygous
  6. Dominant
  7. Recessive

7. What is a Punnett square?

        a. a tool used to measure the angle of a square

        b. a genetic tool used to help predict the results of a cross

        c. a genetic tool used to show the actual results of a cross

        d. a game played at recess

8. Which of the following Punnett squares has not been done correctly.

a.

b.

c.

d.

        

9. Snapdragon flowers come in three different colors red, blue and purple. Is this an example of an incomplete dominant or codominant trait?

        a. incomplete dominant

        b. codominant

        c. neither

        d. both

10. Sex-linked traits are attached to the _____ chromosome.

        a. Y

        b. V

        c. Z

        d. X

/