CHAPTER FOUR

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CHAPTER FOUR

• CELL REPRODUCTION
• (p.96)

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Cell Reproduction

• is also known as cell division
• or mitosis or fission.

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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.

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------------------------------------------------P
arent cell

• the original cell.
• Daughter cells
• - the two new cells that are formed

Parent Cell
Daughter Cell
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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

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MITOSIS is a series of changes or phases
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1) INTERPHASE
WHEN THE CELL IS NOT DUPLICATING.
NORMAL CELL ACTIVITIES.
MOST OF A CELLS LIFE IS SPENT IN INTERPHASE.
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Time spent in the Cell Cycle
4 hours
10 hours
2 hours
4 hours
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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.

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3) METAPHASE

• Spindle fibers attach to the chromosome at their
  middle point.
• - called a centromere.

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4) ANAPHASE

• Centrioles and spindle fibers pull apart the
  chromosomes to opposite sides of the cell.

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5) TELOPHASE

• Centriole and spindle fibers disappear.
• Nucleus reforms.
• Chromosomes have duplicated.
• Cell membrane pinches in to form two daughter
  cells.

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After telophase, cells enter interphase again.
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IDENTIFY THIS STAGE OF MITOSIS
INTERPHASE
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IDENTIFY THIS STAGE OF MITOSIS
METAPHASE
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IDENTIFY THIS STAGE OF MITOSIS
ITS A TOUGH ONE.
PROPHASE
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IDENTIFY THIS STAGE OF MITOSIS
ANAPHASE
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IDENTIFY THIS STAGE OF MITOSIS
TELOPHASE
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In plants, a new cell wall - called a cell plate
- forms between the daughter cells.
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ASSIGNMENTWORKSHEET MITOSIS
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DNA - deoxyribonucleic acid

• a chemical which makes up the chromosomes.
• Key to heredity.
• Duplicated during mitosis.

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Its 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

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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.

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A section of the chromosome called a gene
determines traits.

• Ex. blonde hair, blue eyes, etc

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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.

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DNA Research

• Recombinant DNA
• new DNA created when DNA from one organism is
  combined with another organism.
• also called gene splicing.

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This has created new organisms.

1. oil eating bacteria.
2. Disease resistant potatoes.
3. Insulin producing bacteria.
4. Round-up ready corn

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What if we could replace the DNA strand which
causes cancer?

• Many are against DNA research. We could create a
  very deadly disease.

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Cloning

• a clone is genetically identical to its parent.
• The DNA comes from one parent - not two.
• Good? Bad?

Dolly 1996 -2003
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ASSIGNMENTWORKSHEET DNA
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CLASSIFICATION (P. 22-26)

• methods of grouping things according to
  similarities or differences.
• Ex. by size, color, age, etc.

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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?
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Todays system is called binomial
nomenclature (two-name naming)

• Ex. Canis lupus
• - created by Carolus Linnaeus.

Ex. Canis familiaris
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Latin was used by scientists and scholars in the
1700s.

• used today to avoid the confusion of using many
  different languages.
• Ex. Spanish moss
• - not Spanish
• - not moss

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The Latin names are an organisms genus species.

• Canis familiaris

Genus grouping
Species grouping
Always lower case. Most precise smallest Can
produce offspring
Always capitalized
Both italicized
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Other examples
Homo sapiens sapiens
Felis domesticus
Bison bison
Acer rubrum red maple
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ASSIGNMENTREAD PAGES 22 - 26.
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CLASSIFICATION CATEGORIES

• there are seven different levels of scientific
  classifications.
• it becomes more exact/specific as you move down.

Ex. Bottlenose Dolphin Tursiops truncatus
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Kingdom Animal Phylum Chordate Class
Mammal Order Cetacea Family Delphinadae
Genus Tursiops Species truncatus
King Phillip cried out for goodness sake
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Six Kingdom Classification

• Kingdom Animal
• are multicellular.
• can move from place to place.
• cannot make their own food.

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• Kingdom Plant
• make their own food through photosynthesis.
• can be large (redwoods) or unicellular (plankton)

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• Kingdom Fungi
• -can not move.
• - can not make their own food.
• - absorb food from dead material.
• Ex. mushrooms, mold, yeast.

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• 4) Kingdom Protist
• -are unicellular.
• - have traits of both plants and animals.
• Ex. Euglena
• - can move but it has chloroplasts.

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• 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.
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These kingdoms were formed when Kingdom Monera
was split into two.
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ASSIGNMENTWORKSHEETCLASSIFICATION
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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

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DNA(DEOXYRIBONUCLEIC ACID)
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The structure of DNA was discovered by
Watson and Crick
The shape of DNA is called a
Double Helix
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DNA IS MADE UP OF BASE PAIRS
GUANINE - CYTOSINE
THYMINE - ADENINE
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AN ORGANISM WHICH RECEIVES DNA FROM ONLY ONE
PARENT IS CALLED A
CLONE.