Mitosis and Cell Division

Adapted from

www.worldofteaching.com/powerpoints/biology/Mitosis.ppt

and others

• Use your own paper to take notes and answer the questions in complete statements.

• Use all your resources to fill in information and answer questions:– Textbook– Graphics in the presentation– Internet resources

• Have the worksheet titled “Cell Cycle” handy to fill out the diagram

• See your instructor for each quiz and to check off your task sheet

Part 1- Cell Division and the Cell Cycle

• Cells divide differently depending whether the cells are prokaryote or eukaryote.

http://www.goldiesroom.org/Note%20Packets/02%20Classification/00%20Classification%20Packet--WHOLE.htm

– Prokaryotes• Asexual reproduction

– Budding- (describe this process)

– Binary Fission- (describe this process)

• List each example under the appropriate type of reproduction:

http://www.historyforkids.org/scienceforkids/biology/animals/reproduction/

http://chestofbooks.com/food/science/Domestic-Science-School/Yeast.html

http://www.emc.maricopa.edu/faculty/farabee/biobk/biobookmito.html

http://www.uic.edu/classes/bios/bios100/lecturesf04am/lect06.htm

Yeast

HydraBacteria

Mitochondria

– Eukaryotes• Asexual reproduction

– Mitosis- (describe this process)

» How many chromosomes compared to parent cell?

• Sexual reproduction– Meiosis- (describe this process)

» How many chromosomes compared to parent cell?

Cell Cycle

• The rest of the information will focus on Eukaryotic, asexual reproduction– These all go through the same cyclical

process for making new, exact copies of themselves.

• Before cells divide they have to double cell structures, organelles and their genetic information

Growth, Repair, Replacement

Cell Cycle Worksheet• If you need a copy there is one available on the

wiki here:

Cell Cycle Worksheet• Reference (don’t copy) the following diagram,

others from the internet and the one pictured in your book.– Fill out your worksheet exactly as specified in the

slides following the next diagram. Your grade on the worksheet is dependent on you following instructions.

Cell Cycle- all except Mitosis and Cytokinesis are considered Interphase

Cell Cycle Worksheet

• Label (and color) the correct sections of the outer ring:– Interphase (light blue)– Mitosis (red)– Cytokinesis (yellow)

Cell Cycle Worksheet

• Label (and color) the correct sections of the inner ring under Interphase:– G1 (dark blue)– S (green)– G2 (dark blue)

• Write a brief description in each of these sections of the events that are identified with each phase- check several sources for conformation and completeness.

Cell Cycle Worksheet

• Label (and color them all red) the correct sections of the inner ring under Mitosis:– Prophase– Metaphase– Anaphase– Telophase

• These phases will be described in great detail in Part 3 of the presentation

Cell Cycle Worksheet• Write a brief statement of the events in the

correct sections of the inner ring under Cytokinesis. Color it yellow.

• G0 phase– Draw an arrow showing where G0 would be placed.

– Add a circle at the end of the arrow big enough to write a description what identifies a cell in G0 phase

– Label the circle G0

– Color the circle orange.

Cell Cycle

• A Cell spends about 75% of its life in interphase– Growing– Doing it’s job– (replicating DNA in prep for Mitosis)

Cell Cycle

• During the phase of Mitosis– Copies of DNA are condensed into

Chromosomes and divided up– Cell contents are divided up– Chromosomes and organelles are pulled to

opposite sides of a cell– The cell pinches down the middle in

preparation of splitting

Check Point

• See your instructor for Quiz 1 and to have your notes and worksheet graded.

• Take with you:– Task Sheet– Notes– Cell Cycle worksheet

Part 2- DNA Replication

Eukaryotes vs Prokaryotes DNA

• Eukaryotes have many Chromosomes. How many do each of these animals have:– Dog =_______– Cat = _______– Fruit fly =________– Human = ________

• Prokaryotes have only one Chromosome– Circular structure called a _________.

Human Chromosomes

• Have 46 chromosomes total– 2 sex Chromosomes (one pair)- determine

male vs Female• XX=________• XY =________

– 44 Autosomes (22 pairs) - all the rest of the chromosomes

Haploid vs Diploid

• Haploid (1n or n)- how may different kinds of chromosomes you have – (23 in humans)

• Diploid (2n) - a chromosome and it’s “mate” chromosome to give you a 2 copies of all information (not identical copies- one from mom, one from dad)- Homologous pairs – (46 in humans)

• All cells in your body are _________ except for sex cells (eggs and sperm)

-DNA is in Chromatin form during growth and replication.-Condensed chromosomes are only seen during mitosis

Karyotypes• Pictures taken of condensed chromosomes

in diving cells• Chromosomes are cut out of picture and laid

out with matching chromo pairs

• Often used in genetic counseling to determine risk of identifiable genetic defects of a fetus

• Can easily determine the gender of the fetus

Karyotype from a diploid cell- What is the gender of this baby?- How do you know?

• Down Syndrome is identified by a trisomy of chromosome 21.– What does trisomy mean?

DNA replicates before Mitosis

• Happens during S phase of cell cycle

• Can’t “see” it happen– DNA is still unwound in nucleus as

chromatin– Each chromosome (strand of DNA)

replicates

Structure of DNA

• Structure was discovered in 1953 by James

Watson and Francis Crick

• DNA = Deoxyribose nucleic acid

Made out of

•sugars (deoxyribose)

•Phosphates

•nitrogen bases

Nitrogen Bases are Purines or Pyrimidines

• Purines– ________ and

________ have two rings

– (PuGA 2) could help you remember this

• Pyrimadines– ________ and

________ have one ring

“Chargoff’s rule”- we know which ones pair up because of the amount of each kind found in a strand of DNA

A = _____ & C = ______

Note: -There are _____ hydrogen bonds between A and _____

- There are _____ hydrogen bonds between C and _____

-Draw a diagram similar to this in your notes. -Label all the parts using the key provided. -Fill in the correct letters for the matching base pairs on the bottom strand

Topoisomerase enzyme unwinds and separates the DNA strands to be copied

Figure 3.31b

Replication of DNA

DNA polymerase enzyme matches up nucleotide base pairs and build the complimentary strands

A=T

C=G

G2 phase of Cell Cycle

• Cell rests and error checks DNA replication

• Mitochondria replicate

• Cells get bigger

Check Point

• See your instructor for Quiz 2 and to have your notes graded.

• Take with you:– Task Sheet– Notes

Part 3 Mitosis

Cell Division by Mitosis

• Mitosis is the process by which new body cell are produced for:– Growth– Replacing damaged or old cells.

This is a complex process requiring different stages

Mitosis

• All daughter cells contain the same genetic information from the original parent cell from which it was copied.

• Every different type cell in your body contains the same genes, but only some act to make the cells specialise – e.g. into nerve or muscle tissue.

Mitosis Begins

Use the following slides to write a descriptive statement about what happens in each of the following phases:

-Prophase

-Metaphase

-Anaphase

-Telophase

-Cytokinesis

Cytokinesis:The cell completely splits in two and the nuclear membranes reforms.

Prophase

DNA winds up into Chromosomes of two identical Chromatids bound together by centromere

Metaphase

Anaphase

Telophase and Cytokinisis

Cytokinesis:The cell completely splits in two and the nuclear membranes reforms.

Mitosis Worksheet

• Label each of the phases pictured

• Label the parts indicated in each diagram

AnaphaseProphase

Metaphase Telophase

Picture adopted from: http://www.micro.utexas.edu/courses/levin/bio304/genetics/celldiv.html

Real Pictures- animal cell: Identify each phase. Click the mouse to see if you got them right.

Anaphase

ProphaseMetaphase

Telophase

Picture adopted from: http://www.uoguelph.ca/zoology/devobio/210labs/mitosis1.html

Real Pictures : Identify each phase. Click the mouse to see if you

got them right.

Interphase

Mitosis – bone cell slides1 2

3 4 5

Parent cell Chromosomes copied

Copies separating 2 daughter cells

Cells split

Plants:apical

meristem

Rat – epithelial cells

Extra Credit Opportunity

• Google Mitosis Flip book– Chose a format you like and make a flip

book– Due the day of the test on Mitosis– Check Task sheet for points possible

• Watch the 5 min video again to summarize The Cell Cycle and Division:

• mailto:http://www.youtube.com/watch?v=Q6ucKWIIFmg&feature=player_detailpage

Check Point

• See your instructor for Quiz 3 and to have your notes and worksheet graded.

• Take with you:– Task Sheet– Notes– Mitosis worksheet