CHAPTER FOUR
“CELL REPRODUCTION”
(p.96)
Cell Reproduction
- is also known as cell
division
- or mitosis or fission.
REASONS FOR MITOSIS
Growth
-adding cells to the body.
Replace
- worn-out or dying cells.
Ex. Red blood cells (2-3 million
per second).
Repair
- bruises and cuts.
Reproduction *
- one celled organisms.
-----------------------------------------------Parent cell
- the original cell.
Daughter cells
- the two new cells that are formed
Parent Cell
Daughter Cell
Mitosis
- a type of cell division which produces
daughter cells exactly like the parent.
New cells must have the same number of
chromosomes. The DNA must be
duplicated.
Humans: 46
Fruit Flies: 8
Cat: 32
Potato and Chimp: 48
MITOSIS is a series of changes or
phases
1) INTERPHASE
WHEN THE CELL
IS NOT
DUPLICATING.
NORMAL CELL
ACTIVITIES.
MOST OF A CELL’S LIFE IS SPENT IN
INTERPHASE.
Time spent in the Cell Cycle
Growth and
DNA Synthesis
4 hours
2 hours
4 hours
10 hours
Growth and
Preparation for
Divison
Mitosis
Rapid Growth
2) PROPHASE- first real stage of
mitosis.


Nucleus breaks apart.
-nuclear membrane
disappears
Tube-like structures
called spindle fibers
appear and attach to the
centrioles.
3) METAPHASE
Spindle fibers attach to
the chromosome at
their middle point.
- called a centromere.
4) ANAPHASE
Centrioles and spindle
fibers pull apart the
chromosomes to
opposite sides of the
cell.
5) TELOPHASE




Centriole and spindle
fibers disappear.
Nucleus reforms.
Chromosomes have
duplicated.
Cell membrane pinches in
to form two daughter cells.
After telophase, cells enter
interphase again.
INTERPHASE
TELOPHASE
PROPHASE
ANAPHASE
METAPHASE
IDENTIFY THIS STAGE OF
MITOSIS
INTERPHASE
IDENTIFY THIS STAGE OF
MITOSIS
METAPHASE
IDENTIFY THIS STAGE OF
MITOSIS
IT’S A TOUGH ONE….
PROPHASE
IDENTIFY THIS STAGE OF
MITOSIS
ANAPHASE
IDENTIFY THIS STAGE OF
MITOSIS
TELOPHASE
In plants, a new cell wall - called a
cell plate - forms between the
daughter cells.
ASSIGNMENT:
WORKSHEET “MITOSIS”
DNA - “deoxyribonucleic acid”
- a chemical which makes
up the chromosomes.
- Key to heredity.
- Duplicated during
mitosis.
It’s structure and how it works was a
mystery until 1952.
James Watson and Francis Crick
-proved the shape/structure of DNA
was a double helix. (twisted ladder) p.111
The DNA molecule is made of four
chemicals put into a certain order.
Base pairs
Guanine --- Cytosine
Adenine --- Thymine
- the sequence forms
the hereditary code.
- it controls eye color,
height, allergies, etc.
A section of the chromosome called
a gene determines traits.
Ex. blonde hair,
blue eyes, etc
DNA is duplicated during mitosis
- called replication.
- sometimes an error
occurs (caused by
pollution or x-rays)
called a mutation.
- a permanent
change in the gene.
- most are harmful.
ex. deformed frogs
in Minnesota.
DNA Research
Recombinant DNA
- new DNA created
when DNA from one
organism is combined
with another
organism.
- also called “gene
splicing”.
This has created “new” organisms.
1. oil eating
bacteria.
2. Disease
resistant
potatoes.
3. Insulin producing
bacteria.
4. “Round-up
ready” corn
What if we could replace the DNA
strand which causes cancer?
Many are against DNA research. We
could create a very deadly disease.
Cloning
- a clone is genetically
identical to its parent.
- The DNA comes from
one parent - not two.
- Good?
Bad?
Dolly 1996 -2003
ASSIGNMENT:
WORKSHEET “DNA”
CLASSIFICATION
(P. 22-26)
- methods of grouping things
according to similarities or
differences.
Ex. by size, color, age, etc.
Classifying organisms is called
taxonomy.
- started by Aristotle
in 350 BC.
Many disagreements
about the groupings:
-by air?
-by sea?
-by land?
Where to put frogs? Geese?
Today’s system is called binomial
nomenclature (two-name naming)
Ex. Canis lupus
- created by
Carolus Linnaeus.
Ex. Canis familiaris
Latin was used by scientists and scholars
in the 1700’s.
- used today to avoid
the confusion of
using many different
languages.
Ex. Spanish moss
- not Spanish
- not moss
The Latin names are an organism’s
genus species.
Canis
Genus grouping
Always
capitalized
familiaris
Species grouping
Always lower case.
Most precise
“smallest”
Can produce offspring
Both italicized
Other examples:
Felis domesticus
Homo sapiens sapiens
Acer rubrum ‘red maple’
Bison bison
ASSIGNMENT:
READ PAGES 22 - 26.
CLASSIFICATION CATEGORIES
- there are seven different levels of scientific
classifications.
- it becomes more exact/specific as you “move
down”.
Ex. Bottlenose Dolphin
Tursiops truncatus
Kingdom
Phylum
Class
Order
Animal
Chordate
Mammal
Cetacea
Family
Delphinadae
Genus
Tursiops
Species
truncatus
King Phillip cried out for goodness sake
Six Kingdom Classification
1) Kingdom Animal
- are multicellular.
- can move from
place to place.
- cannot make their
own food.
2) Kingdom Plant
- make their own
food through
photosynthesis.
- can be large
(redwoods) or
unicellular
(plankton)
3) Kingdom Fungi
-can not move.
- can not make
their own food.
- absorb food from
dead material.
Ex. mushrooms,
mold, yeast.
4) Kingdom Protist
-are unicellular.
- have traits of
both plants and
animals.
Ex. Euglena
- can move but it has
chloroplasts.
5) Kingdom Eubacteria
Ex. strep.
6) Kingdom Archebacteria
Ex. stromatolites
-both are prokaryotic.
- unicellular.
- Archebacteria are
‘older’ and more
primitive and can live in
harsh conditions.
The difference between them is their chemical make-up.
These kingdoms were formed when
Kingdom Monera was split into two.
ASSIGNMENT:
WORKSHEET
“CLASSIFICATION”
Asexual Reproduction



New organisms are produced from one parent.
DNA is identical to parent.
Examples





Potato from tuber
Strawberries from runners
Fission: one celled organism divides to form 2
Budding: new organisms grow from one parent (Hydras)
Regeneration: grow back missing parts


More organism grow from parts of one organism
Sponges, planaria, sea stars
DNA
(DEOXYRIBONUCLEIC ACID)
The structure of DNA was
discovered by Watson and Crick
The shape of
DNA is called a
Double Helix
DNA IS MADE UP OF
BASE PAIRS
GUANINE - CYTOSINE
THYMINE - ADENINE
AN ORGANISM WHICH
RECEIVES DNA FROM ONLY
ONE PARENT IS CALLED A
CLONE.
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CHAPTER FOUR - Bismarck Public Schools