Cell as a unit

8/2/2019 Cell as a unit

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CELLASAUNIT

OFLIFE


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LEARNINGOBJECTIVES

From this chapter, you will be able to

identify that cell is the basic unit of living things.

identify, draw, label and state the function of the generalstructures of animal

cells and plant cells.

state the similarities and differences between animal and plantcells.

state the meaning and give examples of unicellular organismsand multicellular

organisms.

name the different types of human cells and state their

functions. state the functions of different types of human cells.

arrange in sequence cell organisation from simple to complexusing the terms

cell, tissue, organ, system and organism.

explain why human beings are complex organisms.


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A cell is the basic unit of living things. All living things are made

up of one or more cells.Do you know that every human being develops from a singlecell?Cells are the smallest living parts in a living thing.Examples :A flat is the basic unit of block of flat.

A brick is the basic unit of wall.Some living things are very simple. They are made up of onlyone cell.Some living things are very complex. The human body is madeup of 50 to60 trillion cells.

.


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MICROSCOPE1. Cells are very small. We cannot seethem with the naked eye.

2. We need the help of a microscope tosee cells.3. A microscope is a tool that enables usto look at small things which cannotbe seen with the naked eye.

Coarse focus knob

Fine focus knob


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Stage clip Keep the slide in position

Coarse focus knob

Fine focus knob


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HANDLINGMICROSCOPE

Use both hands to hold microscope- one handholding the arm and another one supporting thebase.

Place the microscope down gently in an uprightposition in well lit area

Keep the stage and other part of microscope cleanand dry

Clean the lenses with tissue paper to avoidscratching them

Start viewing specimen with low power objectivelens


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UNDERSTANDINGCELL


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ANIMALCELL


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PLANT CELL


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DIFFERENCEOFANIMALCELLANDPLANTCELL


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EXERCISES


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Do the exercise 2.1 from text book page 45


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UNICELLULARANDMULTICELLULARORGANISM

Living things is also called as organism Organism can be divided into unicellular organism and

multicellular organism

Unicellular organism is Organism

made up of one cell(uni means 1)They can only be seen undermicroscopeThey usually live in water(aquatic)

They carry out life process suchas feeding, growing and breathingUsually called unicellularmicroorganismExamples in plant ischlamydomonas & yeastExamples in animal is amoeba

and paramecium

Multicellular organism isorganism made up of more thanone cell (many cell)The examples is : bird, humanbeing and treeSome multicellular organism arevery small and need microscopeto observe

This is called multicellularmicroorganismThe example of multicellularmicroorganism- in animal is hydra -in plant is spirogyra


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UNICELLULARMICROORGANISM

PLANTS

CHLAMYDOMONAS

YEAST

ANIMALS

AMOEBA

PARAMECIUM


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MULTICELLULARMICROORGANISM

PLANT

ANIMAL

HYDRA

SPIROGYRA


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DOEXERCISE 2.2 PG 47


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CELL IN HUMAN BODY

* Human made up ofdifferent types of cell

* Each type of cell carriesout differences function

NERVE CELL

*send informationfrom 1 part to

another part of body EPITHELIAL CELL

*form layer on the

skin to protect thecell below

FAT CELL

*store fat

BONE CELL

*form bone thatsupport body

MUSCLE CELL

*enable bodymovement by

contracting and

relaxing

WHITE BLOODCELL

*protect the bodyagainst diseases

such as bacteria

RED BLOOD CELL

*transport oxygenthroughout the body

HUMAN EGGCELL(ovum)

*femalereproductive cell

HUMAN SPERMCELL

*male reproductivecell


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CELL IN HUMAN BODY


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CELL IN HUMAN BODY

* Human made up of different types of cell

* Each type of cell carries out differences function

WHITE BLOOD CELL


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WHITE BLOOD CELL

*protect the bodyagainst diseasessuch as bacteria


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ORGANIZATIONOFCELL

The human body also have organization

The organization of cell in human body is morecomplex.

They are organized to work together to performdifferent function for the body

Cell Tissue Organ System Organism


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TISSUES

A tissue is a group of similar cells that carry outthe same function. Examples:

Tissues Function

Epithelium tissue Form a layer on skin ororgan to protect cell belowthem

Muscle tissue Made up of muscle cell thatcontract and relaxes toenable movement of the

body

Nervous tissue Carry tissue from 1 part ofthe body to another part


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Organ: skull, bone


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ENDOCRINESYSTEM

To produce hormone tocontrol the bodys

activities anddevelopment


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EXCRETORY SYSTEM

To remove toxicsubstance from thebody

Organ: kidney, urinarybladder


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Organ: muscle


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Organ: spleen


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DIGESTIVESYSTEM

To digest food so it canbe absorbed easily andused by the body

Organ: stomach,oesophagus, mouth


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NERVOUSSYSTEM

To help the bodyrespond to the changeinside and outside thebody

Organ: brain, spinal cord


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RESPIRATORYSYSTEM

To enable gasexchange take place

Organ: lung, trachea, nose


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BLOODCIRCULATORYSYSTEM

To carry oxygen andfood to all part of thebody

Organ: heart, blood vessel


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HUMANBEINGARECOMPLEXORGANISM

Human considered to be a complex organismsbecause they have various types of cells that form

tissues, organs and systems. (cell specialization)

The complex organization of cell in human bodyenables the body to carry out life processes


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DOEXERCISES 2.3 PG-51

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Cell as a unit