Warm-Up1. The creation of energy by plants is called?2. The movement of water through a cell membrane?3. What is the net flow of molecules during diffusion?4. List the following from smallest to largest—organ,

organ system, tissue, organism, cell5. The cell membrane is made up of what molecule?6. What is the shape of that molecule?7. What green pigment absorbs sunlight in plant cells?8. During Photosynthesis, plant cells use energy to

breakdown water into what two elements? 9. Diffusion uses no energy, so it is a _____ process.10. Name two organelles in plant, but not animal cells.

Warm Up1. What are the two types of reproduction in organisms?

2. First experiments in heredity were by who?

3. A unit of heredity occupying a place on a chromosome.

4. The sex chromosomes in humans (alleles).

5. What scientists developed the DNA model?

6. What is the process that uses cell division to replace missing or damaged parts?

7. Name the four phases of mitosis?

8. What type of reproduction is used by ferns, mushrooms?

9. What is the normal life span of a cell called?

10.How large do cells normally grow?

Cell Division Cell Division

Asexual ReproductionAsexual Reproduction

Science 7Science 7

Darren NighDarren Nigh

The Cell Cycle

The cell cycle is the normal sequence of development and division of a cell

The cell cycle consists of two main phases

Interphase: The cell engages in normal life activities

Mitosis and Cytokinesis: The cell undergoes division of the nucleus and cytoplasm

InterphaseInterphase is part of the cell cycle during

which a cell is not dividingDuring Interphase the cell grows to about

twice its original sizeThe cell engages in normal life activities

such as transporting materials in and transporting wastes out.

During this phase the DNA is copied into a new set.

What is DNA?

DNA is deoxyribonucleic acidDNA is a chemical that contains information

needed for an organisms growth and functions

The Watson and Crick Model- showed that DNA is made of two strands of molecules joined in a

structure that resembles a twisted ladder or double helix

Info Break

• What is DNA?

• What is the commonly accepted DNA model known as? What Shape?

• During what phase does the cell engage in normal activities?

Interphase

When the nucleus and nuclear membrane are visible, the cell is in interphase. In addition, the chromosomes are not condensed at this point, so they are not visible.

The part labeled A is a centrioles

Interphase-nucleus is in place

MitosisMitosis is the part of the cell cycle during

which the nucleus dividesThe shortest period in the cell cycle.The function of mitosis is to move the

DNA and other material in the parent cell into position for cell division.

When the cell divides, each new cell gets a full set of DNA and other materials

Prophase• During the stage of mitosis known as

prophase, the centrioles are still moving to opposite poles, and the chromosomes are not lined up at the equator yet.

Animal cell

Animal cell-Prophase

Actual electron microscope viewProphase inside a plant cell

MetaphaseThe stage of mitosis illustrated below is

metaphase.The chromosomes shown below are

lined up along the equator (equatorial plate).

Animal cell

Metaphase-Animal cell

Actual electron microscope viewInside a plant cell

Info Break 1. What is the shortest period in the

cell cycle?2. During what phase are the

chromosomes lined up at the equator?

3. During what phase are the centrioles still moving toward the poles?

AnaphaseAnaphase is identified when the

chromosomes are pulled away from the equator of the cell toward the poles.

Inside an animal cell

Animal Cell

Actual electron microscope viewInside a plant cell

Telephase and Cytokineses

The cell below is in Telophase, the stage of mitosis where a new

nuclear membrane has

formed Cytokinesis or

cytoplasm division is also occurring simultaneously.

A is the cleavage furrow which willbecome the cell membrane

Plant cellA is the cell plate which will become the cell wall

Info Break1. During what phase are the

chromosomes pulled away from the equator toward the poles

2. During what phase does a new membrane form?

3. During what phase is the cytoplasm divided between cells?

Is this an example of a plant or animal cell in mitosis?

Cells go through a process called mitosis to divide.

Specific cells use certain pieces of the information to become particular types of cells.

Ex: liver cells that work together to become the liver organ vs. skins cells that work together to become skin.

Cell division allows for growth and healing of an organism

Ex: when your skin is cut/wounded, cell division causes re-growth of those skin cells. Also, individuals experiencing puberty are going through rapid growth caused by cell division.

Why is cell division important?

www.youtube.com/watch?v=n2Fg9tcjkQM&feature=PlayList&p=3D9371E659BE5BBA&playnext=1&playnext_from=PL&index=28

Cell Division, Asexual Reproduction,

andGenetics

Reproduction is the process by which one organism or species produces others of its same kind.

ReproductionReproduction

There are 2 types of reproduction:

Asexual : A new

organism is produced from 1 organism.

Sexual : A new organism is produced from 2 organisms.

Types of Reproduction

• In Asexual Reproduction organisms are produced from one parent

• The new organism contains genetic information identical to the parent.

• There is much less

genetic diversity compared to sexual reproduction

Asexual Asexual ReproductionReproduction

Binary Fission Binary Fission is a form of Asexual Reproduction occurring in Prokaryotes A parent splits into two completely independent daughter cells exactly alikeSince all Prokaryotes are single celled, cell division and reproduction are the same process

Example: bacteria Textbook Pg. 89

Given this information, Can you explain how people get sick so quickly from a virus?

• They simply just divide in half.

• It only takes about 15-20 minutes for a bacterium to reproduce, so one bacterium can reproduce millions of offspring in just a few days!

BuddingBoth unicellular and multicellular organismsreproduce by budding.An organism develops tinybuds on its bodyEach bud forms from theparent cells, so it is exactlythe same as the parent.A Bud grows until it is a complete or a nearly complete organism.It breaks free and becomes a new, separate organism.

Bud

Example: hydra Page 89

• Spore formation is a process in which cell division creates more spores.

• Spores are reproductive bodies, that are produced by mushrooms, plants, bacteria, and Protozoa and that are widely dispersed.

Ex: Fungi (mushrooms) and the spores on the underside of fern plants.

SporeFormation

• A Process that uses cell division to re-grow damaged or lost body parts is regeneration.

Ex: Sponges, starfish, sea stars, planarians and human beings

Pg. 89 textbook

Regeneration

Humans, for example, are able to regenerate skin and bone tissue to mend wounds and fractures, but are unable to re-grow even a finger if one should be lost. Some internal organs can be regenerated if a large enough part remains as a starting point. The liver is an example; so too are the adrenal glands. The replacement of worn-out tissues is a form of regeneration and goes on throughout life. The most obvious is the replacement of skin (over 27 lbs in a lifetime) from below as the outer layers rub off.

Info Break1. What are the two types of

reproduction?

2. What type of asexual reproduction is used by bacteria?

3. How do fungi reproduce?

4. Are human beings able to regenerate any body parts?

5. What type of sexual reproduction is used by the Hydra?

Conclusion Mitosis is used by eukaryotic cells

whenever genetically identical cells are needed for the following reasons:

1. during growth of the organism 2. for asexual reproduction (some

creatures can re-grow missing limbs, or when cut in two, can grow into 2 complete organisms).

3. when tissues have been damaged and need to be repaired (as in a cut).

4. The complete life cycle of a cell is known as the cell cycle or the cell division cycle.

Sexual reproductionSexual reproduction• A cell containing genetic information from the

mother and a cell containing genetic information from the father combine into a completely new cell in Sexual Reproduction

• The new cell becomes the offspring

HeredityHeredity—the passing of genes from

parents to offspring

A Chromosome is a threadlike linear strand of DNA and associated proteins in the nucleus of eukaryotic cells that carries the genes and functions in the transmission of hereditary

Gene- a section on a chromosome - a trait example: Hair color, eye color

Allele-a specific gene in a genetic pair RR tt Rt Example: red hair, green eyes

Humans have 23 sets (46 chromosomes total) that contain allof the specific genes (alleles) for traits that they possess . Each can be distinguished by size and by unique banding patterns. This set is from a male, since it contains a Y chromosome. Females have two X chromosomes.

This is a picture of an X Chromosome. It contains hundreds of sex linked genes also called traits.

How genetic diseases spread through generations of a family

Phenotype-what traits you see when you look at an organism

Example: plant with purple flowers, white flowersGenotype-the name for the genes (allelles)Example: TT RR BB bb rr etc.

Dominant allele-expressed even if only one gene of that type is present example: Rt RR Bb BB

Recessive allele- expressed only if two genes of that type are present example: rr tt bb

Section 4.1 NotesGene- a section on a chromosome - a trait

example: Hair color, eye color

Allele-a specific gene in a genetic pair RR tt Rt

Example: red hair, green eyes

Phenotype-what traits you see when you look at an organism

Example: plant with blue flowers, green pods

Genotype-the name for the genes a person has

Example: TT RR BB bb rr etc.

Dominant allele-expressed even if only one gene of that type is present example: Rt RR Bb BB

Recessive allele- expressed only if two genes of that type are present example: rr tt bb

Punnett

SquaresView How Stuff Works-Gregor Mendels Rules of

Heredity

Jacob Pullen

Curtis Kelly

Jamar Samuels

Denis Clemente