Meiosis

Meiosis

by Randy Carpenter

Important Terms

​Gametes

​Karyotype

​Homologous Chromosomes

​Haploid

​Diploid

​Spermatocyte

​Oocyte

​Synapsis

​Tetrads

​General Overview of Meiosis

​Meiosis

​Meiosis creates cells with half the DNA of a parent cell (Specifically, one set of chromosomes instead the usual 2 sets). These cells are called Gametes. Gametes are sex cells. Eggs (Oocyte) in women and sperm (Spermatocyte) in males.

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​Meiosis shuffles these two sets of chromosomes like a deck of cards and then randomly deals them out into the gametes.

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​Meiosis will create cells that are different from each other unlike mitosis, which aims to create identical cells.

Multiple Choice

What is a Gamete?

• Male and female reproductive cells

• Genetically identical cells

• The product of mitosis

• A somatic cell (regular body cell) that makes up the general structures of an organism

Multiple Choice

You will find an Oocyte in...

• Men

• Women

Multiple Choice

You will find a spermatocyte in....

• Men

• Women

​Karyotype

​A karyotype is a visual layout of all the pairs of chromosomes of a critter.

Open Ended

You have 46 total chromosomes or 23 pairs/sets. Where do you think you get each pair from? (Be specific)

​Chromosome Pairs

​You get one set of chromosomes from your mom and one set of chromosomes from your dad.

​You get 1 number 1 chromosome from your dad and 1 number 1 chromosome from your mom.

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​How do we know what chromosomes are number 1's instead of number 4's?

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​Homologous Chromosomes

​Homologous Chromosomes

​These are chromosomes with an extremely similar size, centromere location, and gene loci.

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​Homologous Chromosomes

​Homologous chromosomes make up pairs 1 - 22, with the 23rd pair being your sex chromosomes, either an X or a Y. (If your 23rd pair is XY, you are male; if your 23rd pair is XX, you are a female).

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​Your mom and dad will give you one-half of a genetically different set. These genetic differences give you the various traits that make you unique.

Multiple Choice

If your mom gives you an X and your dad gives you an X, what is your sex?

• Male

• Female

Multiple Choice

Can your mom give you a Y chromosome?

• Yes

• No

Multiple Select

What characteristics make up a homologous chromosome? (Choose all that apply)

• Same size

• Same gene loci

• Closest chromosome

• Same centromere location

Open Ended

In your own words tell me what a karyotype is and how we organize it.