Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For...
-
Upload
sharon-rodgers -
Category
Documents
-
view
219 -
download
1
Transcript of Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For...
![Page 1: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/1.jpg)
Chapter 10Cellular Growth and Division
![Page 2: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/2.jpg)
CP BIO Ch. 10 Cell Division
Why are new cells needed?• For growth and repair
– Replace damaged or old cells– Regeneration – replace lost body part– Growth
• For asexual reproduction– Offspring are genetic copies of parent
![Page 3: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/3.jpg)
Regeneration – replace lost body part
starfish can replace an arm flatworms can regrow a body
Lizards can replace a tail
![Page 4: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/4.jpg)
Some organisms reproduce asexually• Offspring are genetic copies of the parent and of
each other
![Page 5: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/5.jpg)
Prokaryotic cells divide by binary fission
![Page 6: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/6.jpg)
One-celled protists also do fission, but
must do mitosis first to divide chromosomes
evenly
Col
oriz
ed T
EM
32
,500
Prokaryotic chromosomes
LM
34
0
![Page 7: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/7.jpg)
– Sexual Reproduction – two parents• Genetic mix in offspring, each is different
p. 274
![Page 8: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/8.jpg)
Some cells divide oftenBone marrow stem cells
Plants and simple organisms
Skin cells Digestive lining cells
embryo
![Page 9: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/9.jpg)
Some divide rarely or not at all
Muscle cells Cartilage or tendon cells
Nerve cells
![Page 10: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/10.jpg)
Eukaryotic nuclei contain many chromosomes
Each chromosome contains thousands of genes - must be organized before cell can dividing Both new cells need EACH gene/chromosome
![Page 11: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/11.jpg)
• DNA is ALREADY COPIED (“replicated”) -coils, condenses
• forms tightly packed, dense “CHROMOSOMES”
• keeps copies organized and intact until cell splits
Chromatin (loose form of chromosome) packs and condenses before a cell can divide
![Page 12: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/12.jpg)
DNA wraps around
histones
DNA
One chromosome (copied and packed
for cell division)
Groups of histones form nucleosomes
This coils and wraps until it all fitsinto the nucleus.
These group to form chromatin
![Page 13: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/13.jpg)
Sister chromatidsidentical copies
Centromereholds chromatids
together
Double-stranded (replicated)
chromosome
SEM of human chromosomes
Prokaryotes have a single, circular chromosome, no histones; no nucleus
![Page 14: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/14.jpg)
Mitotic Phase - cell divides - 2 new cells form
Figure 10.7
Interphase - normal cells - most of cell life - non-dividing cell
Cell Cycle - has two phases
![Page 15: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/15.jpg)
INTERPHASE
S(DNA synthesis)
G1
G2
Cytokin
esis
Mito
sis
MITOTICPHASE (M)
G1 growth, normal life functions
S “synthesis” – DNA replicates
G2 final growth; prepares to divide
INTERPHASE
![Page 16: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/16.jpg)
A) Mitosis – chromosomes condense, organize and divide
- each new cell gets one copy of every chromosome
B) Cytokinesis – cytoplasm divides
INTERPHASE
S(DNA synthesis)
G1
G2
Cytokin
esi
s
Mito
sis
MITOTICPHASE (M)
Mitotic Phase
![Page 17: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/17.jpg)
DNA replicates during S of interphase
1. Molecule “unzips”
2. Free nucleotides match up
with open partner
3. A-T and C-G
4. Two identical molecules
![Page 18: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/18.jpg)
PHASES OF MITOSIS
PROPHASE – cell organizes & prepares• Chromatin • nuclear membrane, nucleolus disappear• spindle and asters form• Centrioles move to poles of cell
METAPHASE – chromosomes in middle• Centromeres attached to spindle fibers
![Page 19: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/19.jpg)
ANAPHASE -chromosomes copies separate• spindle fibers pull chromatids to
opposite poles of cell
TELOPHASE – return to normal• chromosomes relax/uncoil into chromatin
• nuclear membranes form; nucleoli appear• spindle fibers disappear
![Page 20: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/20.jpg)
Animal cytokinesis
• Cell membranes pulls in
• Cytoplasm pinches in two
Cleavagefurrow
SE
M 1
40
Daughter cells
Cleavage furrow Contracting ring ofmicrofilaments
CYTOKINESIS – cytoplasm divides 2 identical daughter cells
![Page 21: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/21.jpg)
TE
M 7
,500
Cell plateforming
Wall ofparent cell
Daughternucleus
Cell wall New cell wall
Vesicles containingcell wall material
Cell plateDaughter cells
Plant cell cytokinesis
- cell wall is rigid
- cell plate forms
- new cell wall grows
NO centrioles or asters
![Page 22: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/22.jpg)
Plant cell mitosis
Same stages
NO CENTRIOLES OR ASTERS
![Page 23: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/23.jpg)
Control of Cell Division
Chemical signals tell a cell when to divide
Normal rate: growth, repair
- asexual reproduction in some organisms
Slow rate: some cell types divide rarely (liver)
- aging slow healing, lose some cells
Rarely or not at all: nerve, muscle, cartilage
Fast rate: some cell types (skin, digestive lining)
- embryo, growth zones (bones, root tips)
Uncontrolled cancer
![Page 24: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/24.jpg)
Growth factors & cyclins• Chemicals secreted by cells • Can start or stop cell
division
After forming asingle layer,cells havestopped dividing.
Providing anadditional supply ofgrowth factorsstimulatesfurther cell division.
![Page 25: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/25.jpg)
Cell Growth and Healing
• Injury – damaged cells secrete growth factors
• Cells at edge of injury start dividing rapidly
• New cells that form heal the break
• As injury heals, cell division slows
![Page 26: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/26.jpg)
Programmed Cell Deathapoptosis
Self-destruct if damaged too much to repair a) DNA damageb) Embryonic development – unneeded cells
![Page 27: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/27.jpg)
DNA damageCells begin to divide abnormally
Continue dividing, invade healthy tissue (malignant)
Spread through blood or lymph stream, can start new tumors
(metastatic)
Cancer is uncontrolled cell division
![Page 28: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/28.jpg)
Tumor
Glandulartissue
A tumor grows from asingle cancer cell.
Cancer cells invadeneighboring tissue.
Cancer cells spread throughlymph and blood vessels toother parts of the body.
Lymphvessels
Bloodvessel
Cancer cells do not respond to signals that regulate the cell cycle• If not treated early, cancer will spread• kills by destroying organ function
![Page 29: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/29.jpg)
What causes cancer?
• Defects in Genes– Cells do not make or do not respond to
control signals• Age and Environmental Injury
– Age, smoking, pollution, asbestos, radiation• Genetic Tendency
– Some cancers run in families (colon, breast)
![Page 30: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/30.jpg)
BE CAREFUL when sunning• Wear sunscreen, sunglasses• Avoid brightest part of the day• Don’t use tanning beds
![Page 31: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/31.jpg)
The most common cancer - skin
![Page 32: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/32.jpg)
Basal cell
Squamous Cell
Melanoma
![Page 33: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/33.jpg)
Cancer treatmentRadiation – high-energy, carefully aimed at tumor
Chemotherapy – drugs specific for tumor types
• interfere with cell division
• some normal cells destroyed, too
– Skin (lose hair); digestive lining (nausea)
Surgery – remove tumor and nearby cells
Boost immune system – healthy diet, reduce stress
![Page 34: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/34.jpg)
Stem cells and differentiation
Differentiate – cells specialize as embryo develops
Stem cell – unspecialized cell
- can differentiate to form many kinds of cells
- depends on chemical signals from nearby cells
![Page 35: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/35.jpg)
Kinds of Stem CellsTotipotent
- can form an entire organism from one cell- fertilized egg embryo full organism
Pluripotent - specialize to form different kinds of cells- embryo cells all cells in an organism
Multipotent – can develop into most, but not all, cell types- adult stem cells many kinds of cells
![Page 36: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/36.jpg)
Multipotent stem cells can form tissues
![Page 37: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/37.jpg)
Ch. 11.4 Meiosis Cell Division for Sexual Reproduction
Sexual Reproduction - two parents
a. Offspring have NEW combination of genes
b. genetic mix of both parents
Advantage – genetic variation
a. Some may have traits that favor survival
b. Variation in individuals allows a species to evolve
![Page 38: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/38.jpg)
a. CONJUGATION
b. Recipient cell gets new genes
Sexual Reproduction in bacteria and protists
![Page 39: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/39.jpg)
Complex organisms – make special cells
a. gametes – sperm and egg
b. Gametes combine in fertilization
- make a zygote new organism
![Page 40: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/40.jpg)
Chromosome Number: Diploid and Haploid
Homologous chromosomes
a. matched chromosome pairs
b. one member of pair from each parent
c. carry genes for the same traitsd. 22 pairs autosomes; one pair sex chromosomes X, Y
Gene for one trait
![Page 41: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/41.jpg)
Cells with paired chromosomes are diploid
a. Somatic (body) cells are diploid
b. 2n (n = number) Humans: 2n = 46
Fruit fly 2n = 8
2 sets of chromosomes
- 2 of every gene
Locus – location of gene on a
chromosome
one chromosome pair
![Page 42: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/42.jpg)
Humans: 2n = 46
23 pairs of chromosomes
One set of 23 came from each parent
Chromosomes photographed during mitosis
![Page 43: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/43.jpg)
Haploid cells have ONE set of chromosomes
(n) = ONE MEMBER from EACH homologous PAIR
human: n = 23 gametes - sperm or egg
![Page 44: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/44.jpg)
Meiosis is “Reduction Division”
Reduces chromosome number
• from diploid to haploid
• Cell DIVIDES TWICE
![Page 45: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/45.jpg)
Meiosis - two cell divisions
2n parent cell
DNA replicates in interphase
First division – pairs separate
Second division – sister chromatids separate
4 haploid daughter cells
![Page 46: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/46.jpg)
Homologous pairs separate in MEIOSIS
TWO cell divisions
- Daughter cells have ½ parent
chromosome number
Diploid cell - Has pairs
(2n=2)
Haploid cells - (n = 1)
Meiosis I - Pairs separate
(n = 1)
Meiosis II - copies separate
(n = 1)
![Page 47: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/47.jpg)
Crossing over – only in meiosis
a. during Prophase I
b. Homologous chromatids trade pieces
c. Increases genetic variation
![Page 48: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/48.jpg)
Meiosis I
Anaphase I
Metaphase IInterphase
Prophase I
Telophase I
Cytokinesis
![Page 49: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/49.jpg)
Meiosis II
Prophase II
Metaphase II
Anaphase II
Telophase II
Haploid (n) cellsDoubled chromosomes
Haploid cellsSingle chromosomes
![Page 50: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/50.jpg)
Compare mitosis and meiosis
![Page 51: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/51.jpg)
Making sperm and egg
Sperm:2n parent cell 4 haploid sperm
Ovum:2n parent cell 1 haploid egg+ haploid polar bodies
![Page 52: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/52.jpg)
Ovum needs all the cytoplasm
Ovum and polar body Sperm needs only nucleus(DNA)
- flagellum
- mitochondria for energy
![Page 53: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/53.jpg)
Causes of genetic variation
1. Homologous pairs have different genes
• same traits, but may be different forms
2. Crossing over – homologs trade pieces before
separating new gene combinations
3. Pairs position in Metaphase I - independent
• n pairs 2n possible combinations
4. Random fertilization of eggs by sperm
• Any egg or sperm is equally likely to be used
5. Gene or chromosome mutation
- Error in replication or cell division
![Page 54: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/54.jpg)
Many different gene combinations in haploid gametes
Combination 1 Combination 2 Combination 3 Combination 4
Gametes
Metaphase II
Two equally probablearrangements of chromosomes at
metaphase I
Possibility 1 Possibility 2
Figure 8.16
Chromosomes line up randomly in meiosis
![Page 55: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/55.jpg)
When meiosis goes wrong
Nondisjunction
- do not separate correctly
In mitosis defective nucleus, cell usually dies
In meiosis defective gamete
wrong number of chromosomes in zygote
![Page 56: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/56.jpg)
Accidents during meiosis wrong chromosome number
Nondisjunction in meiosis I
Normal meiosis II
Gametes
n + 1 n + 1 n 1 n 1
Number of chromosomes
Nondisjunction in meiosis II
Normal meiosis I
Gametes
n + 1 n -1 n n
Number of chromosomes
Nondisjunction in meiosis I Nondisjunction in meiosis II All gametes abnormal Some gametes normal
![Page 57: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/57.jpg)
If cell is fertilized after nondisjunction trisomy in zygote
Sperm cell
Egg cell
n (normal)
n + 1
Zygote2n + 1
Trisomy = 3
Wrong chromosome number in zygote wrong number in every cell in organism
![Page 58: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/58.jpg)
KARYOTYPE picture of a person’s chromosomes
Photographed during mitosis
- sorted into homologous pairs
- largest-to-smallest
- sex chromosomes last
Abnormalities visible:
- missing or extra
- pieces broken or moved
- pieces added or lostautosomes sex chrom.
Trisomy 21
![Page 59: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/59.jpg)
Normal male karyotype
Normal female karyotype
![Page 60: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/60.jpg)
Down SyndromeTrisomy chromosome # 21
![Page 61: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/61.jpg)
Turner Syndrome XO
Figure 8.22B
Characteristic facialfeatures
Web of skin
Constrictionof aorta
Poor breastdevelopment
Under developedovaries
![Page 62: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/62.jpg)
Klinefelter Syndrome XXY
![Page 63: Chapter 10 Cellular Growth and Division. CP BIO Ch. 10 Cell Division Why are new cells needed? For growth and repair –Replace damaged or old cells –Regeneration.](https://reader035.fdocuments.us/reader035/viewer/2022081513/56649d095503460f949db84c/html5/thumbnails/63.jpg)
Other chromosomes mutations