CELLS ARE NOT JUST IN PRISONS

© T.P. Thould

May 1999

CELLS

Cells are the smallest unit of life which can perform the seven characteristics of living things.

Every Plant and Animal is made up of cells

Different cells are adapted to do different jobs in the bodies of plants and animals. These are called SPECIALISED CELLS

LIVING THINGSEvery living thing - plant and animal have eight common features (characteristics).

These eight characteristics are shared by all living things.

They must have all eight characteristics to be called a living thing.

THE EIGHT CHARACTERISTICS OF LIVING THINGS

1 Movement

2 Respiration

3 Sensitivity

4 Cells

MRS C FERG

5 Feeding

6 Excretion

7 Reproduction

8 Growth

Test

1 Movement - find food, escape , etc..

2 Respiration - for energy

3 Sensitivity - detect stimuli

4 Cells - to form the body tissues and organs that can carry out the other seven life processes.

5 Feeding - for growth and repair

6 Excretion - get rid of waste

7 Reproduction - survival of the species

8 Growth - to mature, to repair

AN ANIMAL CELL

CELL MEMBRANE

CYTOPLASM

NUCLEUS

E.g. A cheek lining cell

A PLANT CELL

NUCLEUS

CYTOPLASM

CELL MEMBRANE

CELLULOSE CELL WALL

CHLOROPLASTS

VACUOLE

E.g. A Palisade Leaf Cell

Test

COMMON STRUCTURES

Plant and animal cells have the same three structures in common, what are they?

What other structures does the plant cell have that the animal cell does not? N

COMMON STRUCTURES

Plant and animal cells have the same three structures in common:-

Nucleus

Cytoplasm

Cell Membrane

A PLANT CELL

Cell WallChloroplasts

Large Vacuole

These parts are only found in plant cells.

PLANT AND ANIMAL CELLS COMPARED

Plant Cells Animal Cells

•Have a nucleus

•Have a cell membrane

•Have cytoplasm

•Have a nucleus

•Have a cell membrane

•Have cytoplasm

•Can have chloroplasts

•Have cellulose cell walls

•Have large vacuoles which contain cell sap

•Regular in shape

•Never have chloroplasts

•No cell wall

•May have small food vacuoles

•Irregular in shape

Eyepiece Lens

Objective Lens

Mirror

StageFocusing

Knob

Handle

PARTS OF A MICROSCOPE

Test

BY NOW YOU SHOULD KNOW…..

•How to set up a microscope

•The parts of the microscope

•What the parts of the microscope do

•That slides need to be stained to be seen more clearly e.g. by Iodine

BY KNOW YOU SHOULD KNOW…..

•The main parts of a plant and animal cell

•The differences between plant and animal cells

•The similarities between plant and animal cells

NUCLEUS

This is the control centre of any cell. It controls all of the cells chemical reactions. It is found in the

Cytoplasm in both animal and plant cells

It contains thread - like strands which are called Chromosomes. These have the Genes which instruct the cell on how it is to grow and function

ChromosomesGenes

CYTOPLASM

This is the jelly - like part of a cell where the nucleus is found. Chemical reactions take place here and different substances are made.

Animal cells are made mainly of Cytoplasm but Plant Cells have a thin layer of Cytoplasm

CELL MEMBRANE

It controls materials going in and out of the cell.

This is a thin skin surrounding the

Cytoplasm.

CELLULOSE CELL WALL

Cell Membrane

This holds plant cells together and gives it strength.

Only plant cells have Cellulose Cell Walls they are never found in animal cells

VACUOLE

This contains a watery liquid called Cell Sap which helps to keep the cell firm and stop the plant from wilting

Plant cells have large vacuoles but only a few animal cells have small food vacuoles

CHLOROPLASTS

These are structures found in the cytoplasm which contain Chlorophyll. This absorbs

sunlight energy during Photosynthesis

Only plant cells contain

Chloroplasts

•The different parts of Plant and animal cells

•The main functions ( Jobs ) of the different parts of the cells

BY NOW YOU SHOULD KNOW …..

SPECIALISATION

• Not all cells look the same

• Not all cells do the same job

• Different cells do different jobs ( functions )

• They are Specialised

• They are adapted to do a particular special job

• Their shape and parts help them to do the special job - this is SPECIALISATION

WHAT ARE THESE?

A

B

C D

WHAT IS THEIR JOB

(FUNCTION?)

HOW ARE THEY ADAPTED?

E

N

A SPERM CELL

Tail for swimming

Nucleus with male

chromosomes

Acrosome to make a hole in the ovum wall for the sperm to get into the ovum

Mitochondrion to make energy to move the tail

Its job is to fertilize the ovum ( egg ) cell Test

A PALISADE CELL

CHLOROPLASTS

These have Chlorophyll which absorbs the energy from the sunlight and uses it to make sugar by Photosynthesis

Makes food for the plant to use for growth, energy etc.

A CILIATED EPITHELIAL CELL

Cilia These cells line the windpipe and the Cilia trap dirt and dust particles stopping them blocking the lungs up and causing disease.

The Cilia brush the dust up and out of the windpipe

They also line the Oviduct and move the Egg along it towards the Womb

A ROOT HAIR CELL

Absorbs water from the surrounding soil particles.

SOIL

Root Hair gives the cell a larger surface area through which it can take in more water.

AN OVUM CELL

Contains the female set of chromosomes.

Allows only one sperm inside before blocking any other

ones from getting in

Nucleus

Cell Membrane

WHAT ARE THESE?

A

B

C D

WHAT IS THEIR JOB

(FUNCTION?)

HOW ARE THEY ADAPTED?

E

N

BY NOW YOU SHOULD KNOW…..

•What is meant by Specialised Cell

•How to recognise four specialised cells

•What there functions are

•What adaptations the cells have to do their jobs

The remaining slides are Year 10 work.

If you have finished and learned the work so far then have a go at these.

MORE SPECIALISED

CELLSRED BLOOD CELL

WHITE BLOOD CELL

NERVE CELL

MUSCLE CELL

Click on these in turn and copy the diagrams and notes into your books.

EXTRA WORK IF YOU HAVE FINISHED THE REST!

WHITE CELL

Defends body against disease by killing Microbes - Bacteria and Viruses

White Cell

Defends body against disease by killing Microbes - Bacteria and Viruses

They do this by engulfing them - surrounding the bacteria and trapping it inside the cell and

destroying it.

They also make chemicals called Antibodies which kill the bacteria a few days after being infected.

Bacterium

Red Blood Cell

Carries Oxygen by joining it to the red pigment - Haemoglobin forming Oxyhaemoglobin

To do this well it has no nucleus and a biconcave shape giving it more surface area to carry more Oxygen

around the body

Dendrons connects with other nerve

fibres

Myelin Sheath

insulates the fiibre

A Nerve Fibre

Muscle

Cell Body

Carries impulses from one part of the body to another. The longest cell in the body.

Direction of impulse

Muscle Cells

Long cells which pull when they get shorter ( contract) making different parts of our body move

Muscle Cells

Long cells which pull when they get shorter ( contract) making different parts of our body move