Meiosis

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Question​:

What is Mitosis?

Asexual reproduction

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So​matic cells are body cells

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​P- prophase

M- metaphase

A- anaphase

T- telophase​

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46 Chromosomes​

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Mitosis ​

A form of Cell Division

Sexual Reproduction

• Sex cells divide producing Gametes with 23 Chromosomes ​

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Gametes: are an organism's reproductive cells​

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Meiosis ​

A form of Cell Division

Sexual Reproduction

• Sex cells divide producing Gametes with 23 Chromosomes ​

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Gametes: are an organism's reproductive cells​

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Meiosis ​

​Details

Somatic cells vs. Gamete cells​

Somatic cells are body cells that undergo mitosis​

Gamete cells are reproductive cells that undergo meiosis​

Multiple Choice

Which of the following cells is a gamete?

• egg
• bone
• heart
• muscle

​Sexual reproduction occurs when two organisms of the same species share DNA in order to create

new and genetically unique offspring.

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A warrior princess donates 23 chromosomes and a comedian donates 23 chromosomes

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What are some benefits that could result in their offspring?

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Meiosis ​

​Interphase

​Cell growth phase and DNA replication (same as mitotic cells)

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Cell Division

​Cells undergo PMAT 2 twice reducing the number of chromosome in half

​from 46 to 23

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Meiosis Reproductive cells​

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Prophase I (1) - Crossing over ​(genes cross over)

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Meiosis ​

​Prophase I

​Crossing over

• Exchange of genetic material between two homologous (same) chromosomes

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Meiosis ​

Multiple Choice

What causes genetic variation in meiosis?

• crossing over of chromosomes
• separation of chromosomes
• chromosomes pulling apart

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​Prophase I

Chromosome form and Crossing over​ occurs

Metaphase I

align in the middle​​

Anaphase​ I

Pull apart​

​Telophase I

2 genetically unique cells​

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Meiosis ​

Multiple Choice

What phase is  shown in the picture?

• anaphase 1
• anaphase 2
• metaphase 1
• telophase 1

​Without DNA replication the cell undergoes cellular division again (reducing chromosomes)

​Prophase II

Metaphase II​​

Anaphase​ II​

​Telophase II

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Resulting in 23 Chromosomes​

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Meiosis ​

​Meiosis produces 4 GENTICALLY UNIQUE CELLS with half the number of Chromosomes

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​Write in Details:

Diploid (2n​)

46 Chromosomes

• Somatic (body cells)​

​Haploid (1n)

23 Chromosomes

• gamete cells after PMAT II

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​Vocab Terms

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Multiple Choice

A human being has a somatic cell that has 46 chromosomes.  What is the haploid number found in a gamete?

• 23
• 46
• 69
• 92

When the gamete cells are shared, they fuse

together to form a single cell known as the zygote.

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The chromosomes from each haploid gamete cell join together to create a diploid cell with a full set of chromosomes. This zygote is the first cell of a new, a unique organism.​

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​Parents contribute half the number of chromosomes for each child

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crossing over of each parents chromosomes ensures additional genetic variation

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​Genetic Variation

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​Summarize Meiosis