Download Mitosis

Survey
yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project

Document related concepts

Biochemical switches in the cell cycle wikipedia , lookup

Meiosis wikipedia , lookup

DNA repair wikipedia , lookup

Cell nucleus wikipedia , lookup

Cell cycle wikipedia , lookup

Cell growth wikipedia , lookup

List of types of proteins wikipedia , lookup

DNA damage theory of aging wikipedia , lookup

Amitosis wikipedia , lookup

Mitosis wikipedia , lookup

Chromosome wikipedia , lookup

Transcript
Biology is the only subject in
which multiplication is the same
thing as division…
Regents Biology
2006-2007
MITOSIS:
Making New Cells
Making New DNA
Regents Biology
Where it all began…
You started as a cell smaller than
a period at the end of a sentence…
Regents Biology
Getting from there to here…
 Going from egg to baby….
the original fertilized egg has to divide…
and divide…
and divide…
and divide…
Regents Biology
Why do cells divide…
 One-celled organisms


for reproduction
asexual reproduction (clones)
amoeba
 Multi-celled organisms

for growth & development
 from fertilized egg to adult

for repair & replacement
 replace cells that die from
normal wear & tear or from injury
Regents Biology
starfish
Dividing cells…
 What has to be copied
DNA
 organelles
 cell membrane
 lots of other
molecules

 enzymes
Regents Biology
plant cell
animal cell
Copying DNA
 A dividing cell duplicates its DNA
creates 2 copies of all DNA
 separates the 2 copies to opposite ends
of the cell
 splits into 2 daughter cells

DNA
cell
Regents Biology
nucleus
 But the DNA starts
loosely wound in
the nucleus
 If you tried to divide
it like that, it could
tangle & break
Organizing & packaging DNA
DNA
cell
nucleus
DNA has been
“wound up”
DNA in chromosomes in
everyday “working” cell
cell
nucleus
4 chromosomes
in
thisBiology
organism
Regents
DNA in chromosomes in cell
getting ready to divide
Chromosomes of Human Female
46 chromosomes
23 pairs
Regents Biology
Chromosomes of Human Male
46 chromosomes
23 pairs
Regents Biology
Paired bases
 DNA structure

double helix
 2 sides like a ladder
 Bases match together

A pairs with T
A:T

C pairs with G
C:G
Regents Biology
phosphate
sugar
N base
Watson and Crick
Regents Biology
Copying DNA
 Matching bases allows
DNA to be easily copied
Regents Biology
Making new DNA
 Copying DNA
replication
 DNA starts as a double-stranded
molecule

 matching bases (A:T, C:G)

then it unzips…
Regents Biology
DNA replication
 Strands “unzip” at the weak bonds
between bases
Regents Biology
DNA replication
DNA bases
in nucleus
 Enzyme
DNA polymerase
 adds new bases

DNA
polymerase
Regents Biology
Copying DNA
 Build daughter DNA
strand
use original parent
strand as “template”
 add new matching
bases
 synthesis enzyme =
DNA polymerase

DNA
Polymerase
Regents Biology
New copies of DNA
 Get 2 exact copies of DNA to split
between new cells
DNA
polymerase
DNA
polymerase
Regents Biology
Copied & Paired Up Chromosomes
centromere
Regents Biology
Copying & packaging DNA
 When cell is ready to divide…
copy DNA first, then…
 coil up doubled chromosomes
like thread on a spool…

 now can move DNA around cell without having it
tangle & break
Regents Biology
Copying DNA
Coil DNA into
compact chromosomes
double-stranded
human chromosomes
ready for mitosis
Regents Biology
DNA must be duplicated…
chromosomes in cell
DNA in chromosomes
cell
nucleus
4 single-stranded chromosomes
duplicated chromosomes
duplicated
chromosomes
Biology chromosomes
4Regents
double-stranded
cell
nucleus
Mitosis: Dividing DNA & cells
 Stage 1: cell copies DNA
Copy DNA!
DNA
cell
nucleus
Regents Biology
(interphase)
Mitosis: Dividing DNA & cells
 Stage 2: DNA winds into chromosomes

DNA is wound up into chromosomes to
keep it organized
duplicated chromosomes
Wind up!
cell
nucleus
Regents Biology
(prophase)
Mitosis: Dividing DNA & cells
 Stage 3: Chromosomes line up
chromosomes line up in middle
 attached to protein “cables” that will
help them move

Line up!
duplicated chromosomes
lined up in middle of cell
Regents Biology
(metaphase)
Mitosis: Dividing DNA & cells
 Stage 4: Chromosomes separate
chromosomes split, separating pairs
 start moving to opposite ends

Separate!
chromosomes split &
move to opposite ends
Regents Biology
(anaphase)
Mitosis: Dividing DNA & cells
 Stage 5: Cell starts to divide
cells start to divide
 nucleus forms again

Divide!
Regents Biology
(telophase)
Mitosis: Dividing DNA & cells
 Stage 6: DNA unwinds again
cells separate
 now they can do their every day jobs

Bye Bye!
Regents Biology
(cytokinesis)
New “daughter” cells
 Get 2 exact copies of original cells
same DNA
 “clones”

Regents Biology
Cell division in Animals
Regents Biology
Mitosis in whitefish embryo
Regents Biology
Mitosis in plant cell
Regents Biology
onion root tip
Regents Biology
Overview of mitosis
interphase
I.P.M.A.T.C.
prophase
Please Make Another Two Cells
cytokinesis
Regents Biology
metaphase
anaphase
telophase