Cells

CellsCells are the basic unit of structure and function in

living things.(Name the five kingdoms of living things.)

Plant Cell

Animal Cell

Differences in plant and animal cells

Plant cells have :1. Cell walls2. Chloroplast3. Large Vacuole Animal Cells have :3. NO cell wall4. NO chloroplast5. Smaller vacuole

OrganellesOrganelles are tiny structures within the cell that carry outspecific functions.

Cell WallThe rigid layer of non-living material that surrounds the cells of plants and some organisms.It supports and protects the cell.

Cell MembraneControls what substances come into and out of a cell. All cells have a cell membrane.

NucleusLarge oval structure found inside the cell. Cell’s control center, directing all of the cell’s activities including growth and reproduction.

Do You Know???1.What do we call cells that have a nucleus?

2.What do we call cells that do not have a nucleus?

3.What do we call organisms made of one cell?

4. What do we call organisms made of more than one cell?

eukaryotic

prokaryotic

single-celled

multi-celled

Nuclear MembraneSurrounds the nucleus and protects it. Materials pass in and out of the nucleus through its small openings or pores.

ChromatinThin strains of genetic material in the nucleus that directs the functions of the cell.

NucleolusA structure in the nucleus where ribosomes are made.

Organelles in the CytoplasmCytoplasm is the clear, thick, gel-like fluid between the nucleus and cell membrane that is constantly moving. All cells have cytoplasm.Organelles located here functions to produce energy, build and transport needed materials, and store and recycle waste.

Cytoplasm

MitochondriaRod-shaped organelles that produce energy the cell needs to carry out functions.

They are known as the “powerhouses”.

Endoplasmic ReticulumA maze of passageways that carry proteins and other materials from part of the cell to another.

RibosomesThese organelles produce proteins.

Golgi BodiesThey receive proteins and materials from the E.R, package them, and distribute them to other parts of the cell.

VacuolesStore food, water, and other materials needed by the cell. They also store waste products.

LysosomesThese contain chemicals to break down large food particles and old cell parts to be recycled. This is the cell’s “clean-up crew.”

ChloroplastsThe organelles capture energyfrom sunlight and use it to produce food for the cell.

Bacterial Cells•Bacteria are single (one) – celled microscopic

organisms. Bacteria do not have anucleus.(prokaryotic) Inside a bacterial cell, the chromosome material is floating inside the cytoplasm. • Some bacteria have circular DNA called

plasmids. •Ribosomes are also found in the cytoplasm.•Bacteria have a cell membrane and a cell wall.

Some have a flagellum.

Division of Labor

Within multi-cellular organisms there is division of labor. Division of labor means that the work (labor) of keeping the organism alive is divided (division) among the different parts of the body. Each part has a job to do and as each part does its special job, it works in harmony with all the other parts.

The arrangement of specialized parts within a living thing is sometimes referred to as levels of organization.

Levels of Organization

Level One – Cells

Cells are the basic unit of structure and function of all living things.

Cells: LOTS of Different Kinds!Here are two examples. Can you guess what kind?

Nerve Cells Skin Cells

Second Level: Tissues

There are four basic/major types of tissues in the human body: Muscle tissue, nerve tissue, connective tissue, and epithelial tissue.

In any multi-cellular organism, cells rarely work alone. Tissues are a group of similar cells that perform the same function.

Let’s Look Again…

Here are the cells we saw before, but if you look closely, you can see that they all look similar. Nerve cells working together make nerve tissue, and skin cells make up a special type of epithelial tissue.

Taken One At A Time….Connective tissue connects and supports parts of the body. Blood, fat, ligaments, cartilage, bones, and tendons are all connective tissues.

Nerve tissue carries messages back and forth between the brain and every other part of the body. The brain, spinal cord, and nerves are made up of nerve tissue.

Epithelial tissue covers and lines the surfaces of your body and organs, inside and out. They primarily serve as protective barriers. Skin is one example.

Muscle tissue can contract, or shorten. Because of this, muscle tissue makes parts of your body move.

Level Three: OrgansWhen a bunch of different types of tissues work together,

they form an organ. There are many organs in the body. How many can you name??

GET IT????

Level Four: Organ SystemsEach organ in your body is part of an organ system, a group of organs that work together to perform a major function.

For example, your heart is part of your circulatory system, which carries oxygen and other materials throughout your body. Besides the heart, blood vessels are organs that work in your circulatory system.

The nervous system detects and interprets information from the environment outside the body and from within the body; controls most body functions.

The immune system fights disease.

The excretory system removes wastes.

The endocrine system controls many body processes by means of chemicals, like hormones.

The muscular system enables the body to move; moves food through the digestive system, and keeps the heart beating.

The skeletal system supports and protects the body, and works with the muscular system to allow movement; makes and stores blood cells and stores some other materials.

The digestive system takes food into the body, breaks the food down into smaller particles, and absorbs the digested materials.

The respiratory system takes oxygen into the body and eliminates carbon dioxide.

The reproductive system produces sex cells that can unite with other sex cells to create offspring; controls male and female characteristics.

Let’s Review….

• 1st Level: Cells working together form

• 4th Level: Organ Systems, which work together to form

• 2nd Level: Tissues, which can form

• 3rd Level: Organs, which work together to form

• 5th Level: Organisms!