View
219
Download
0
Category
Preview:
Citation preview
8/8/2019 Chromosomes and Cell Reproduction
1/16
Chromosomes and CellChromosomes and Cell
ReproductionReproduction
8/8/2019 Chromosomes and Cell Reproduction
2/16
Cell Cycle
Cell cycle- cycle of cell growth
Interphase -
G1- rapid cell growth
S- DNA synthesis
G2- final growth phase
Mitosis - nucleus division (PMAT)
Cytokinesis - dividing of cytoplasm and cell
membrane
Interphase- first three phases
8/8/2019 Chromosomes and Cell Reproduction
3/16
Phases of Cell Cycle
8/8/2019 Chromosomes and Cell Reproduction
4/16
Control of the Cell cycle
8/8/2019 Chromosomes and Cell Reproduction
5/16
Cancer Canceris the uncontrollablegrowth of cells
One of the genes atcheckpoints in cell cycle is
mutated, so cancer cells
keeps dividing
Usually bodys immunesystem destroys cancer cells,
if not forms a tumor
Older individuals have a
higher likelihood of cancerdue to many mutations over
time
8/8/2019 Chromosomes and Cell Reproduction
6/16
Prokaryotic (Bacterial) Division
Prokaryote cells are much smaller/simpler
Divide more quickly
Contain a single circular DNA molecule Go through a process ofBinary Fission
form of asexual reproduction that produces
offspring identical to parent (clones)
8/8/2019 Chromosomes and Cell Reproduction
7/16
Process of Binary Fission
1) DNA is copied soeach cell is identical
2) Cell membrane
pinches off between
copies
3) Results in 2
identical cells
http://www.youtube.com/watch?v=4lmwbBzClAc&feature=related
http://www.youtube.com/watch?v=gEwzDydciWc
8/8/2019 Chromosomes and Cell Reproduction
8/16
Bacteria Reproduction
8/8/2019 Chromosomes and Cell Reproduction
9/16
8/8/2019 Chromosomes and Cell Reproduction
10/16
Eukaryotic Division
Information in DNA is
organized in genes
Gene - segment of
DNA that codes for
protein
Genes determine how
a persons body will
develop and function
Genes are onchromosomes
8/8/2019 Chromosomes and Cell Reproduction
11/16
Chromosome number
Different species havedifferent numbers of
chromosomes in their
nuclei
No particular pattern tochromosome numbers
8/8/2019 Chromosomes and Cell Reproduction
12/16
Human chromosomes
All human somatic
(body) cells contain
two sets/pairs of23 chromosomes
(total of46)
This is a karyotype.
8/8/2019 Chromosomes and Cell Reproduction
13/16
Chromosome number (cont.)Two types of cells:
1) Haploid cells (1n) - one
set of chromosomes
(gametes - sperm andegg)
2) Diploid cells (2n) - two
sets of chromosomes
(somatic cells - all othercells)
8/8/2019 Chromosomes and Cell Reproduction
14/16
Is this a boy or girl?
Of the 23 pairs ofchromosomes, 22 areautosomal
They have no effect ongender. They are thesame in males &females.
Sexchromosomes - thelast set determines
genderXX- female
XY- male
8/8/2019 Chromosomes and Cell Reproduction
15/16
When things go wrong
Changes in chromosome #
or structure can cause
abnormal development
Trisomy 21 - three copies of
chromosome #21 aka Downs syndrome
Karyotype - photo that
shows chromosomes
Used to determineabnormalities/mutations
Mutations -change in
chromosome structure
8/8/2019 Chromosomes and Cell Reproduction
16/16
Chromosome Mutations
12 3 4 5 6
12 3 4 5 6
Deletion something is missing (1 2 3 4 6)
Inversion - reversed (1 2 4 3 5 6)
Translocation - from another location(1 2 9 3 4 5 6)
Duplication - doubled (11 2 2 3 4 5 6)
Nondisjunction - failure to separate These will either be totally missing or an
entire extra copy will be present
Recommended