Meiosis Web Quest

Directions: You will need to obtain 4 colored pencils: blue, red, purple, yellow (or as close to those colors as possible). Type in www.cellsalive.com to your browser. Under the left hand menu you will see Interactive…Meiosis (ßclick).

Before you start the animation….

Why is meiosis important?

Some words to know…

Oogonium=immature egg cell Spermatogonium= immature sperm cell Dyad= sister chromatids (refer to these an necessary!)

Meiosis occurs in (circle one) sex cells | body cells

*Play the animation!*

Now let’s go back… click on the word for still-shots and the magnifying glass for answers.

Diploid Cell (2N)

When egg and sperm begin meiosis, how many pairs of chromosomes do they have? (If you are unsure of what 2N means, refer to your notes!)

How many copies of DNA do sex cells have upon entering meiosis?

What happens to the chromosomes?

Prophase I

Sketch the cell in prophase I (use color in order to gain full perspective).

Click on the magnifying glass next to “Prophase I”:

____________________ are pairs of homologous chromosomes.

What important process occurs during prophase I?

What is a chiasma?

How many tetrads are present during prophase I for this particular animation?

a) 1; blue/red pair

b) 2; blue/red pair + purple/yellow pair

c) 2; blue/purple pair + red/yellow pair

d) 4; blue sister chromatid + red sister chromatid + purple sister chromatid + yellow sister chromatid

Metaphase I

Sketch the cell during Metaphase I (continue to use color; take into consideration that crossing over has occurred during prophase I, therefore your color scheme will be slightly different!)

Click on the magnifying glass next to “Meiosis I”:

____________________________ attach to each sister chromatid (dyad).

The tetrads align at the cell _____________________.

Anaphase I

Sketch the cell in Anaphase I (continue to use color):

Click on the magnifying glass next to “Anaphase I”:

What happens to the sister chromatids during anaphase I?

Telophase I

The resulting cells of telophase are (circle one) haploid | diploid, which means they have (circle one) 1 | 2 pair(s) of chromosomes.

Prophase II

What reforms during prophase II?

Metaphase II

Sketch the CELLS (yes, both) in metaphase II (continue to use color):

Go back and compare metaphase I and metaphase II. You will immediately notice some differences.

Metaphase I consists of (1 | 2 )cell(s), with two (tetrads | sister chromatid pairs),whereas Metaphase II consists of (1 | 2 )cell(s), each with two (tetrads | sister chromatid pairs).

Anaphase II

Sketch the cells in anaphase II (color):

What occurs during anaphase II?

Telophase II

Sketch the cell during telophase II (need I mention color?)

*Notice the chromosomes are fuzzy, this is because during telophase the chromosomes decondense back into chromatin*.

The presence of a cleavage furrow indicates the beginning of __________________________.

Gamete (1N)

How many cells does meiosis end with?

How many pairs of chromosomes does each cell have?

How many copies of DNA does each cell have?

Analysis Questions

How many cells does meiosis start with?

How many cells does meiosis end with?

Are the cells created during meiosis identical to, or different from the original parent cell. Why or why not?

Can tetrads be found in meiosis II? Why or why not?

How many pairs of chromosomes do the resulting cells of meiosis have?