Captain Andrew Jaggery —GUILTY of Murder
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Transcript of Captain Andrew Jaggery —GUILTY of Murder
REPRODUCTIONREPRODUCTION2 Kinds of Reproduction2 Kinds of Reproduction
Asexual --
One parent Sexual
--Two parents
Specifically-- Sperm and
Egg
Chromosomes and Cell DivisionChromosomes and Cell Division ChromosomesChromosomes – – Structures in a Structures in a
cell’s cell’s nucleus that contain genes.nucleus that contain genes.
Genes – Found on chromosome in cell. Gives living thing a certain trait and tells a cell how to grow/develop.
How do all forms of How do all forms of asexual reproduction end asexual reproduction end
in an organism?in an organism?Through the process ofThrough the process of
MITOSIS!
(Form of reproduction requiring only one parent.)1. Grow2. Repair3. Replacem
ent
Why do organisms go
through asexual reproduction??
Cell Division — 6 phasesCell Division — 6 phasesMitosisMitosis — 4 phases — 4 phases
1. Interphase —normal life functionsToward the end—
chromosomes duplicateHuman
s-46
Once duplicated-
92Sister chromatids held
together-centromere2.
Prophase--Mitosis beginsNuclear membrane
breaks downCentrioles begin to move &
Spindle forms between3.
Metaphase-
Centromeres line up in the MIDDLE4.
Anaphase--Centromeres split—move to opposite sides
Nuclear membrane appearsCytoplasm divides
End result==2 NEW DAUGHTER CELLS
Is this a problem?? Why?
5. Telophase--
Mitosis is complete!
6. Cytokinesis-- Exactly like the parent
cell!
Cell Division/MITOSIS!!Cell Division/MITOSIS!!IIPaintedMyAunt’sToesCrimson!
InterphaseProphaseMetaphaseAnaphaseTelophaseCytokinesis
Actual “Mitosis” only happens in phases 2-5!
Sexual ReproductionSexual Reproduction
Process calledProcess called MEIOSISResults in the formation of 4
daughter cells called GAMETES (sex cells)Gametes—reproductive cells that have
only half the number of chromosomes as the parent cell
What is the name of the gametes in humans?SPERM & EGG
Production of new organism from 2 parents, Production of new organism from 2 parents, a male and a female.a male and a female.
23 23
46
chromosomes
chromosomes
chromosomes
- New person not exactly like each parent.2 complete cells join, new baby has twice the chromosomes as
each parent.
Prophase 1—chromosome number is doubled
Metaphase 1--line up in the middle
Anaphase 1—sister chromatids begin pulling apart
Telophase/Cytokinesis 1--Two new daughter cells
NO PROPHASE!!!!Metaphase 2—Line up in the middle
Anaphase 2 & Telophase 2—Pulls apart and separates
End Result—4 new cells with
half of the number of
chromosomes as the parents
Let’s Compare!!Let’s Compare!!Asexual Asexual
ReproductioReproductionn
Sexual Sexual ReproductioReproductio
nnNumber of Number of parentsparentsType of cell Type of cell divisiondivisionNumber of Number of daughter daughter cells cells producedproducedGenetic Genetic Makeup of Makeup of offspringoffspring
21
Mitosis
Meiosis
2 4 (gametes)Identical to
the parentUnique;
different from parents
MeiosisMeiosis(Process that produces sex cells with ½ (Process that produces sex cells with ½
number of number of chromosomes of parent cell.)chromosomes of parent cell.)
46 chromosomes
Sperm or Egg Cell
2446
46
23
23
23
23
Sperm or Egg Cells
Let’s watch Let’s watch meiosismeiosis in in action!action!
Advantages/Disadvantages of Advantages/Disadvantages of Asexual/Sexual ReproductionAsexual/Sexual Reproduction
Asexual Reproduction
Advantage
Organism does notneed a mate to produce offspring.Disadvantage
Offspring exactlylike parents.
Sexual Reproduction
Advantage
Gives species variation.
Disadvantage
2 parents neededfor reproduction.
SpeciesSpecies(Group of similar organisms that can (Group of similar organisms that can mate with one another and produce mate with one another and produce
fertile offspring.)fertile offspring.)
Why Why mitosismitosis and and meiosismeiosis??