CellsThe Building

Blocks of Life

Cells

Tissues

Systems

Organs

Organism

Simple Tissues: Cells of the same type work together to perform a specific function

Complex Tissues: Several types of cells work together to perform a specific function

Different tissues work together to perform a specific function

Several organs working together for a common purpose

Various systems work together to form the organism

Animal CellPlant Cell

• Cells observed under the light microscope.

Animal CellPlant Cell

• Cell Are the basic structural and functional units of life

• Cells can exist:– Singly as independent unicellular organisms

– Or As part of multicellular organisms

What are Cells?

Multicellular and Unicellular Organisms

-Cell Are the basic structural and functional units of life -Some organisms body is made up of single cell that

organisms are called : Unicellular Organisms

Eg:- Amoeba , Paramecium.

-other oraganisms body is made up of more

than one cell these organisms are called :

multicellular organisms.

Eg:- Human Body, different types of animals .

Cell Structure:

(1) Nucleus – The Control Centre

Function

• Control centre for cell’s activities

• Control cell division

• Contains genetic materials

Cell Structure:

(2h) Chloroplasts

Structure

Disc-like structures found in leaf

cells

Contains a chlorophyll - green

pigment

Function

Carries out photosynthesis

Chlorophyll absorbs light energy

which is converted to chemical

energy

Cell Structure:

(2) Plasma/Cell Membrane

Properties

• Present in ALL living cells• Made up of fats and

proteins• Controls the exchange the

substances between the cells and their environment

Cellulose Cell Wall

• Function

–Provides shape to the plant cells

–Protects cell

Comparing plant and animal cell

Plant Cell Animal Cell

1-Cell wall

2-chloroplast

1-Cell membrane

2-Nucleus

3-cytoplasm

4-vacuole

Differentiation

Red blood cell

Muscle cell Epithelial cell

Nerve cell

Xylem vessel cell

Root Hair cell

nose

tracheabronchus

lungs

Respiratory system Blood circulatory system

Takes in oxygen from the surroundings. Releases carbon dioxide and water vapour into the surroundings.

Carries food, oxygen and water to various parts of the body and carries wastes away to be removed.

Muscular system

Enables movement

different systems

that is found in

human

From Cells to Tissues

Within a multicellular organism,

Cells of the same type are often arranged in groups to form a simple tissue.

Some simple animal tissues are designed to:

Move a bone/organ by contraction Protect the structures beneath them

Muscle tissue Epithelial tissue

From Cells to Tissues

Within a multicellular organism,

Cells of different types can be arranged in groups to form a complex tissue.

The different cells work together to perform A SINGLE function.

Some complex animal tissues are designed to:

Carry electrical impulses Join all parts of the organism

Nerve tissue Connective tissue

Some simple plant tissues are designed to:

Protect a plant against injury and drying-out of its inner parts

Epidermal tissue

Some complex plant tissues are designed to:

Vascular tissue

Carry out photosynthesis

Photosynthetic tissue

Transport food and water to various parts of a plant

From Cells to Tissues

From Tissues to Organs

• Different tissues in organisms are often grouped together to form an organ.

It is responsible for carrying out more complex functions.

•Most animal organs (heart, lungs, skin) are made up of connecting tissues and some other specialised tissues.

The stomach wall consists of glandular, muscular and connective tissues

The heart consist of muscular, blood and connective tissues

An organ performs a number of different functions.

E.g. Our liver stores food and produces bile.

From Organs to Systems

•Different organs are then linked together to form a body system.

The functions performed by a body system are more complex than those performed by the organs.

•A number of systems are found in complex organisms to carry out essential bodily functions, such as:- Ensure genetic diversity- Digest food- Eliminate wastes, etc.

•An organism is made up of different systems working effectively individually as well as together in a group.

From Systems to Organisms• Different types of multicellular organisms are made up of different numbers and types of systems.

Heart muscle cell (a cell)

Heart muscle (a tissue)

A group of similar cells that are specialised to perform a certain function together to form a tissues.

The heart (an organ)

A group of specialised tissues that are gathered in a certain part of the body to perform a particular functions together to form an organ.

Circulatory system

Various organs that work together to perform a major function in the body to form a system.

Different systems work individually, but together, they make up the whole organism.

Thank you for Listening

Done by :Marwa Husni

For Tr .: Tessi

Class: Seven