Science 8 Plant and Animal Cells

Cell: The Basic Unit of Life

Unicellular and Multicellular Organisms

Unicellular (single-celled):-Made up of only one cell -Unicellular organisms are simple- lack tissues and organs -Cannot grow very large, must take in all materials they need through cell membranes so most can only live in watery, food-rich surroundings

Ameoba: - Common unicellular that live in water- Move using pseudo pods- Use pseudopods to catch food

Paramecium

• move swiftly through water• Move through use of cilia – hair

like• Cilia sweep food into the oral

groove located on one side•

Multicellular (many-celled): -Made up of 2 or more cells -Bigger and more complex-May look different because they are specialized for specific functions -Can live in a wide variety of environments (get energy from variety of foods)-Have specialized cells (more efficient than unicellular organisms)

The cell is the smallest unit of life. Cells with similar structure and functions are organized into tissues. Tissues that work together for a common purpose

Science 8 Plant and Animal Cells

from organs, and an organ system is a group of organs that work together for a common purpose.

---- --- Cells Tissues-- Organs --

Cell Size: Why don’t we see very big cells?

All cells need a supply of materials and get ride of wastes.Materials leaving and entering the cell must do so across the cell membrane. A larger cell needs more material and produces more wastes. With a largervolume the materials and wastes have to travel further . So… Cells are at a size in which they function most efficiently

Organisms get bigger by adding more cells.

Organ System

Science 8 Plant and Animal Cells

Science 8 Plant and Animal Cells

Organelles: Structures inside the cell that has a specific function

Structure Function

Nucleus “Command center”Directs all cellular activities such as

movement, growth and other life functions.

Mitochondria “Powerhouse”Where the energy the cell receives is

converted into a form it can use

Cell Membrane “Controllable gateway”Lets needed materials in and waste out

Vacuoles Where nutrients, water and other substances can be stores by the cell. Plant cells have one big one but animal cells have many smaller ones.

Cytoplasm “Kitchen”Contains the nutrients required by the cell.

Cell Wall “Fame”Found only in plant cells. Provides strength and support to the plants.

Chloroplast “Solar Panels”Contains chlorophyll for photosynthesis, converting the sun’s energy into food for

the cell. Found only in plant cells

Science 8 Plant and Animal Cells

Science 8 Plant and Animal Cells