What is an Organism?

Definition:

Organism – anything that can live on its own

Unicellular Organisms

• - an organism made of only one cell• - Called Prokaryotes: • - No nucleus • - Each organism has a way of moving,

obtaining food, and carrying out all other functions essential for life.

Examples of Unicellular Organisms

• Amoeba

• Bacteria

• Protozoa

•Paramecium

Definition:Multicellular organism – an organism made of

two or more cells

Information:These organisms are able to be seen with the

naked eye.

Multicellular Organisms

Multicellular Organisms

• Called Eukaryotes: Has a well formed nucleus.• Has organelles which are parts of the cell that

carry out specific functions.– Example: Mitochondria has the task of energy and

Chloroplasts has the task of photosynthesis.

• Has movement and a way of food production.• Examples: Animals, plants, fungi, and protists

Make a T Chart in your notes

• Head to my homework site and follow the link• You need to complete a T-Chart representing

the differences between unicellular and multicellular organisms.

Cell Parts and Cell Size

Chapter 1.3Page 28-35

Activities that Keep Cells Alive

• Obtaining materials and supplies for energy.• Making products.• Getting rid of wastes.

Organelles

• Are structures in a cell with a specific function necessary for life.

• Many of these organelles have only been discovered since the invention of the electron microscope.

Differences between Plant and Animal Cells

• There are three differences with the plant cell organelles that animal cells do not have.– Plants and Fungi have a cell wall while animal cells

do not. Cell walls are made mostly of a tough material called cellulose. They are thicker and more rigid than cell membranes and provide support.

Differences between Plant and Animal Cells

– Plant cells also have chloroplasts while animal cells do not. Chloroplasts are the structures in which the process of photosynthesis takes place. Photosynthesis uses energy from the Sun to make carbohydrates. Folded membranes inside each chloroplast contain the green pigment chlorophyll, which absorbs sunlight.

Differences between Plant and Animal Cells

– The third key difference is while both animals and plants have vacuoles, the vacuoles in the plant cells are much larger to be able to store more water.

Cell Parts in Both Animals and Plants

• Cell Membrane: surrounds the cell and protects it. But it also controls the movement of substances in and out of the cell.

• Cytoplasm: a large part of the cell is taken up by this supportive, jelly-like substance. It helps distribute materials such as oxygen and food throughout the cell.

Cell Parts in Both Animals and Plants• Endoplasmic Reticulum:

Is a folded membrane

Forms systems of canals within cytoplasm

Materials are transported in canals to

different parts of the cell.

Cell Parts in Both Animals and Plants

• Nucleus:–Controls the cells’ activities–Contains the chromosomes– Enclosed by a nuclear membrane that

controls what enters and leaves the cell.

Cell Parts in Both Animals and Plants

• Mitochondria:• Energy production for cell.• Tiny food particles broken down for energy.• “Powerhouse” of the cell.

Cell Size

• Why are cells sooo small?

• You are swimming in a pool…If the pool gets bigger, what happens if you are trying to swim across it several times?

Cell Size

• To carry out their work, cells need a constant supply of materials such as oxygen, water and food and get rid of waste.

• The only way in or out is through the cell membrane.

• To grow bigger, organisms add more cells to their bodies rather than grow bigger cells.

Chapter 1 Review

Page 36-37

Quiz on Friday!

• STUDY• What are the characteristics of life?• Microscope Handout (front and back)• Cell Worksheet (front and back)• Animal and Plant cell drawings with labels.• Notes

• If you are not here for the test, you will write it on Monday during lunch.