IBBiology @Skyline High School

                                                                                                                                                                     

 

Meiosis Unit Plan (10 days)

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Assessment Statements

Meiosis

4.2.1

State that meiosis is a reduction division of a diploid nucleus to form haploid nuclei.

 

4.2.2

Define homologous chromosomes.

 

4.2.3

Outline the process of meiosis, including pairing of homologous chromosomes and crossing over, followed by two divisions, which results in four haploid cells.

 

4.2.4

Explain that non-disjunction can lead to changes in chromosome number, illustrated by reference to Down syndrome (trisomy 21).

 

5.4.6

Explain how sexual reproduction promotes variation in a species.

 

10.1.1

Describe the behaviour of the chromosomes in the phases of meiosis.

 

10.1.2

Outline the formation of chiasmata in the process of crossing over.

 

10.1.3

Explain how meiosis results in an effectively infinite genetic variety in gametes through crossing over in prophase I and random orientation in metaphase I.

 

10.1.4

State Mendel’s law of independent assortment.

 

10.1.5

Explain the relationship between Mendel’s law of independent assortment and meiosis.

 

10.2.2

Distinguish between autosomes and sex chromosomes.

 

10.2.3

Explain how crossing over between non-sister chromatids of a homologous pair in prophase I can result in an exchange of alleles.

 

 

Karyotyping

4.2.5

State that, in karyotyping, chromosomes are arranged in pairs according to their size and structure.

 

4.2.6

State that karyotyping is performed using cells collected by chorionic villus sampling or amniocentesis, for pre-natal diagnosis of chromosome abnormalities.

 

4.2.7

Analyze a human karyotype to determine gender and whether non-disjunction has occurred.

 

4.3.5

Explain how the sex chromosomes control gender by referring to the inheritance of X and Y chromosomes in humans.

 

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What You Need to Know

Meiosis:

Contrast sexual with asexual reproduction.

Provide an example of an organism that reproduces sexually / asexually.

What is the function of meiosis?

Define and compare the number of chromosomes in diploid versus haploid versus polyploid cells.

When during meiosis is the cell diploid?  When does it become haploid?

What is the diploid and haploid number in humans?

What are germ cells?  Gametes?

What are homologous chromosomes?  Alleles?

What are some similarities / differences between mitosis and meiosis?

Describe the events that happen during each phase of meiosis.

Identify the difference between chromosomes, replicated chromosomes and chromatids

What are tetrads?  When during meiosis do they appear in the cell?

What is crossing over?  When does it happen?

Where does crossing over occur along the chromosome? 

What are recombinant chromosomes?

Will linked genes that are closer together or further apart have higher rates of crossing over?

Why do linked genes show different phenotypic ratios than unlinked genes?

 

Non-disjunction

Contrast results of non-disjunction in meiosis I vs. meiosis II in terms of the number of chromosomes in the gametes produced.

What are nullisomy, monosomy, trisomy and polysomy?

Understand the notation of non-disjunction (i.e. 2n-1).

Know the number of chromosomes that are found in individuals with common diseases that result from non-disjunction

Patau syndrome

Edward's syndrom

Turner’s syndrome

Down syndrome

Super female

Jacob’s syndrome

Klinefelter’s syndrome

 

Karyotypes

Identify autosomes and sex chromosomes.

Identification male vs. female.

Identify chromosomal diseases (listed above) using a karyotype.

Understand the notation of karyotypes (i.e. 47, XY, +21).

Describe the karyotyping procedure.

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Unit Activities List  

Meiosis notes and diagram

Meiosis modeling activity

Meiosis worksheet

Dragon genetics activity

Crossing over notes

Crossing over case study

Variation notes

Non-disjunction notes

Down's syndrome case study

Karyotyping notes

Karyotyping activity

Stevens and sex determination reading

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Key Terms

 

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Helpful Links

Independent Assortment

Meiosis

Mitosis and Meiosis - Interactive Exercise

Mitosis vs Meiosis

Mitosis/Meiosis Simulation

Sexual Reproduction

 

 

"When we tug at a simple thing in nature, we find it attached to the rest of the world."  John Muir