Transcript Cell Cycle

Functions
Genome
 Entire set of DNA in each cell of an org
 Normally one circular chromosome in
prokaryotes
Binary Fission
Single chromosome replicates
One pulls away
Membrane & wall separate cell
Human Genome
 6,000,000,000 base pairs long
 Somatic cells’ DNA is split into 46
chromosomes
 23
are maternal
 23 are paternal
Diploid
(2n)
 Gametes have ½ the DNA which is
split into 23 chroms
Haploid
(n)
Human Genome (♀)
(♂)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
X Y
Human Chromosome
 A length of DNA
 Each
has a homologous
chromosome
CENTROMERES
♀ ♂
Homologous Pair
Human Chromosome
 A length of DNA
 Each
has a homologous
chromosome
 1000’s of genes
 1,000,000’s of base pairs
 Combined with proteins
AT
CG
CG
GC
AT
TA
TA
TA
CG
GC
GC
CG
TA
♀ ♂
Homologous Pair
Chromosome Replication
Each chromosome
replicates to form
identical chromatids
Attached by
centromeres
Cell Cycle
Splitting of the rest
of the cell
Identical distribution of
replicated DNA into nuclei of 2
daughter cells
Late Interphase
 Centrosomes replicate
Prophase
 Chromosomes supercoil
 Nucleoli disappear
 Spindle forms
Spindle Elongation
Prometaphase

Nuc envelope breaks down
 mtubules from opposite poles
attach to kinetochores
Metaphase
 Spindle fibers force chroms
to metaphase plate
Anaphase
 Chromatids migrate toward
opposite poles
 Nonkinetochore
elongate cell
mtubules
Anaphase

Chromatid may “walk” along
mtubule toward pole
Telophase
 Cell continues elongation
 Nuclear envelopes reform
 DNA uncoils
Cytokinesis (animal)


Microfilaments
constrict cell to
form cleavage
furrow
Membrane
pinches off
Cytokinesis (Plant)
 Cellulose
vesicles gather
in the middle of
the cell forming
the cell plate
Mitotic Review