CHAPTER FOUR “CELL REPRODUCTION” (p.96) (p.96)

-is also known as cell division -or mitosis or fission. Cell Reproduction

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 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 - a type of cell division which produces daughter cells exactly like the parent.

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 10 hours 4 hours 2 hours 4 hours

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

After telophase, cells enter interphase again. INTERPHASE PROPHASE METAPHASE ANAPHASE TELOPHASE

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 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. -the sequence forms the hereditary code. -it controls eye color, height, allergies, etc. Base pairs Guanine --- Cytosine Adenine --- Thymine

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

ASSIGNMENT: WORKSHEET “DNA”

CLASSIFICATION ( P ) -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 familiaris Genus groupingSpecies grouping Always capitalized Always lower case. Most precise “smallest” Can produce offspring Both italicized

Other examples: Felis domesticus Acer rubrum ‘red maple’ Homo sapiens sapiens Bison bison

ASSIGNMENT: READ PAGES

CLASSIFICATION CATEGORIES -there are seven different levels of scientific classifications. -it becomes more exact/specific as you “move down”. Ex. Bottlenose Dolphin Tursiops truncatus

KingdomAnimal PhylumChordate Class Mammal OrderCetacea FamilyDelphinadae GenusTursiops Speciestruncatus 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. New organisms are produced from one parent. DNA is identical to parent. DNA is identical to parent. Examples Examples Potato from tuber Potato from tuber Strawberries from runners Strawberries from runners Fission: one celled organism divides to form 2 Fission: one celled organism divides to form 2 Budding: new organisms grow from one parent (Hydras) Budding: new organisms grow from one parent (Hydras) Regeneration: grow back missing parts Regeneration: grow back missing parts More organism grow from parts of one organism More organism grow from parts of one organism Sponges, planaria, sea stars 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.