Science Form 1 Chapter 2: Cell is the unit of life

7/23/2019 Science Form 1 Chapter 2: Cell is the unit of life

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CELL AS A UNIT OF LIFE

Science form 1



2.1 What is aCell?

1. A cell is the basic nitof life.

2. Its fnction is to carr!

ot life "rocesses.



Who #isco$er cells?

Theodor Schwann 1839

% All animal tissues are composedof cells&



Cells

All li$in'or'anismsare ma#e

ot of cells

Animal

(mans

)lants

Smallestnit

Fnctionan#sr$i$e on

its o*n

+ro*th,

res"iration,#i$ision an#

e-cretion

Will #ie ot e$entall!.

All ne* cells are forme# b!cell #i$ision of other cells

mitosis/

0ierentsies an#sha"es

Lon',short,o$al, has

tail



3icrosco"e

1. A microsco"e is se# to st#! the'eneral strctre of a cell.



4o#! tbe

Nose"iece

Lo* "o*er

3e#im"o*er(i'h "o*er

Sta'e cli"s

0ia"hra'm

Li'ht sorce

E!e"iece

Arm

Sta'e

Coarsea#5stment

Finea#5stment

4ase



No. 3icrosco"e "art Fnction

1. 4o#! tbe 6

2. Nose"iece (ol#s the lo*, me#im an# hi'h "o*er ob5ecti$elenses, can be rotate# to chan'e ma'ni7cation

8. Lo* "o*erOb5ecti$e lenses 9 ma'ni7cation ran'es from 1:-to ;:-

;. 3e#im "o*er

<. (i'h "o*er

=. Sta'e cli"s (ol# the sli#e in "lace

>. 0ia"hra'm e'lates the amont of li'ht on the s"ecimen

@. Li'ht sorce )ro5ects li'ht "*ar#s thro'h the #ia"hra'm,the s"ecimen an# the lenses

. E!e"iece Contains oclar lens

1:. Arm Use# to s""ort the microsco"e *hen carrie#11. Sta'e S""ort the sli#e bein' $ie*e#

12. Coarsea#5stment

3o$es the sta'e " an# #o*n for focsin'

18. Fine a#5stment 3o$es the sta'e sli'htl! to shar"en the ima'e

1;. 4ase S""orts the microsco"e





Animal an# "lant cells

Cellmembran

eC!to"las

mNcles

Chloro"last

Bacole

Cell *all



Animal cells )lant cells

Irre'lar in sha"e e'lar in sha"e

No cell *all (a$e cell *allNo chloro"lasts (a$e chloro"lasts

3ostl! no $acoles (a$e lar'e

$acoles



The fnctions of cellstrctre

Strctre Fnction

Ncles Controls all cellacti$ities

C!to"lasm A "lace *herechemical "rocessestae "lace

Cell membrane Controls Do* of

materials in an# otof cell

Cell *all +i$es sha"e to the

cell



First science form 1 "ro5ect

• 4il# a mo#el that sho*s thestrctre of animal an# "lant cells

E-am"le



2.2 Unicelllar an# mlticelllar

or'anisms

1. A nicelllar or'anisms has one cellonl!.

2. A mlticelllar or'anisms has man!cells.



)aramecim E'lena Amoeba

Unicelllar or'anisms

Chlam!#omonas





3lticelllar or'anisms

S"iro'!ra

(!#ra

S"oran'im



2.8 Cell or'anisation in the (man

4o#!

Cell sim"le/

Tisse

Or'an

S!stem

Or'anism

com"le-/



1. The t!"e an# fnction of hman

cells







2. Tisse

Tisse is a 'ro" of similar cells that*or to'ether to "erform a "articlarfnction.

E"ithelialtisse

3scletisse

Ner$etisse

Connecti$e tisse



8. Or'an

An or'an consists of t*o or more in#sof tisses 5oine# into one strctre thathas a certain tas.

; S t



;. S!stem

• +ro"s of or'ans form or'an s!stems

• Each s!stem carries ot a ma5or

acti$it! in the bo#!.



<. Or'anism

All s!stem in the bo#! fnction in acoor#inate# manner to form amlticelllar or'anism.



2.; (man bein' 9 a com"le-

or'anism

1. A hman bein' is a com"le-mlticelllar or'anism becase thecells are or'anise# into tisses,

or'ans an# s!stems.

2. Cell s"ecialisation hel"s to #i$i#ebo#! fnction amon' the #ierent

t!"es of cells.8. Cell s"ecialisation an# cell

or'anisation ensre the life

"rocesses are carrie# ot eecti$el!

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Science Form 1 Chapter 2: Cell is the unit of life