Mitosis and Meiosis

What is this a picture of?

1 2 3

4 5 6

Mitosis Notes

Mitosis is when a cell separates the chromosomes in its nucleus to make two identical cell copies

Cell Division Cycle (Cell Cycle)

Periods of the Cell Cycle:

1. Interphase: when cell grows and duplicates DNAa. G1(gap or growth phase): cell

prepares to replicate chromosomes

b. S (Synthesis) phase: DNA synthesis or replication occurs

c. G2 (gap or growth phase): cell prepares for mitosis by making microtubules to pull apart chromosomes

2. Mitosis: chromosome separates3. Cytokinesis: cell forms a cleavage

furrow and divides into two identical cells

Importance of Mitosis 1. Growth – cells divide to help you grow

2. Repair and Renewal – need cells to divide to heal wounds and replace old dead cells

3. Reproduction- organisms that reproduce asexually use mitosis to make new organisms Usually spores Different from bacterial reproduction

Mitosis Picture Sort

Directions:

1. Put the pictures of mitosis in the correct order.

2. Match the picture with the name of each step of mitosis

3. Match the description with picture and name of each step of mitosis

4. Finally, paraphrase description and copy onto notes

Hello!

Hi gang!

I have completely lost my voice. But, don’t worry. We will still have lessons today. Yay! I will need your full attention today. I will also need all of you to help each other and make sure everyone is on task. Warm up is on the white board. Here is our agenda:

1. Meiosis Notes

2. Peer Review Introduction (Make sure you have a hard copy of your introduction with you)

3. Reading Packet – Annotations and 1 Page PD due

Meiosis Notes

Make sure you have a copy of the meiosis notes!

Today, we will be doing notes a little differently. First, we will do our usual note taking. Then, we’re going to watch a video on meiosis and I will take notes with you as we watch the video. Feel free to let me know if you want to pause or have any questions.

Meiosis

Meiosis is how sex cells (sperm and eggs) are made from germ cells

Overview of Meiosis Video- http://www.youtube.com/watch?v=D1_-mQS_FZ0

Meiosis Video (http://www.youtube.com/watch?v=ijLc52LmFQg) – Remember, I will be taking down notes with you on the white board. Get markers if you need. There are a lot of parts to it.

I also need someone near the laptop to help me pause the

* video. Thanks!

Draw Something – Mitosis and Meiosis Review

SOMEONE READ THE INSTRUCTIONS BELOW

Take out your genetics, mitosis, meiosis notes

One person will randomly be selected to be the drawer.

Quanina will provide the drawer with the word you need to draw on the white board and the category to the class. The drawer may not give hints on the board

After the drawer is finished with the drawing, people can shout out potential answers. If the person gets it correct, the person who answered correctly can choose another drawer. If the person does not answer correctly, the drawer can change his drawing or wait

Playing for Points (participaton pts for ppl who participate :-)

Peer Review Introduction Papers Swap your introduction paper with at least 3 people

Write annotated by: Your Name on the top front page before you review the paper

Check for Technicalities, Completeness, or Cohesiveness in Technicalities: grammar errors, spelling, sentence structures,

etc Completeness: does it have all of the required elements (check

introduction handout and make sure it includes everything asked for)

Cohesiveness: Do the paragraphs connect the main idea of the introduction? Are there parts of the text that are unnecessary?

Peer Review Introduction Papers

When you are done, show me your paper for a final look over and you can start revising it or working on your reading packet

Reading Packet Due Wednesday April 18

Final Draft of Introduction Due Friday April 20

BEFORE YOU LEAVE (11:07a)

Reading Packet Due Wednesday April 18

Final Draft of Introduction Due Friday April 20th

Before you leave make sure I see you paper with the names of the 3 graders for credit!

Meiosis I

Interphase 1:

Chromosomes replicate (S phase)

Cell grows and prepares for Meiosis I (G1 and G2)

Centrosomes (proteins that pull apart DNA) replicate

Meiosis I

Prophase I:

Homologous chromosomes find each other and form Tetrads

Crossing over occurs between non-sister chromatids Crossing over: parts of the DNA switches between non-sister

chromatids

Spindles attach Chromosomes

see white board

Meiosis I

Metaphase I

Tetrad (pairs of homologous chromosomes)lines up on the metaphase plate

Homologous chromosomes line up in a random order.

Meiosis I

Anaphase I

Homologous chromosomes get pulled toward the poles (where centrosomes are)

Meiosis I

Telophase I and Cytokinesis

Cleavage furrow forms and cell divides into 2 cells

Each cell has one copy of two sister chromatids

Differences between Meiosis I and Mitosis

Homologous chromosomes find each other and form Tetrads in Meiosis but not Mitosis

Crossing over occurs between non-sister chromatids in Meiosis but not Mitosis

Homologous chromosomes line up in a random order in Meiosis but not Mitosis

Video Recap

Meiosis II

Prophase II Chromosomes are in pairs (diads) Spindle forms

Meiosis II

Metaphase II Chromosomes line up on the metaphase plate Kinetochores of sister chromatids are attached to microtubules

that link to the poles

Meiosis II

Anaphase II Sister chromatids separate and move to opposite poles

Meiosis II

Telophase II and Cytokinesis Nuclei(nucleus) forms and chromosomes decondense Four haploid daughter cells are produced We can now make babies!

MitosisMeiosis