BIOLOGY

Chapter 2 : comparison between Animal & plant cell

Ø Similarities :

Both cell have :

Nucleus ,  cytoplasm , plasma membrane , mitochondrion , golgi apparatus , ER and ribosomes

Ø Differences :

                                   i.            Plant Cell have cell wall while animal cell does not have cell wall.

STRUCTURE	ANIMAL CELL	PLANT CELL
SHAPE	IRREGULAR SHAPE	FIXED SHAPE
CELL WALL	NO CELL WALL	HAVE CELL WALL
VACUOLE	NO VACUOLE, IF PRESENT VACUOLE  ARE TOO SMALL	LARGE CENTRAL VACUOLE
CHLOROPLAST	NO CHLOROPLAST	HAVE CHLOROPLAST
CENTRIOLE	HAVE CENTRIOLE	NO CENTRIOLE
FOOD STORAGE	IN FORM OF GLYCOGEN	IN FORM OF STARCH

CELL STRUCTURE AND CELL ORGANISATION

TYPE OF CELL	FUNCTION	ORGANELLES FOUND ABUNDANTLY
SPERM CELL	NEED ENERGY TO MOVE TOWARDS Fallopian tube during fertilisation	mitochondrion
Muscle cells	Need energy to contract and relax to enable movement	mitochondrion
Cell in meristem	Need energy during cell division	mitochondrion
Palisade mesophyll cell	Absorb sunlight during photosynthesis	chloroplast
Pancreatic cells & cells in salivary gland	Synthesis & secrete enzyme	Golgi apparatus ribosome Rough ER
Liver cells	Detoxification of drugs and poisons	Smooth Er

PHYSIC FORM 4 CHAPTER 1

PHYSICS

Chapter 1 :Introduction to Physics

1.1           Understanding Base Quantities and Derived           

                                                                              Quantities

1.   A physical quantity is a measureable quantity.

2.Base Quantities are physical quantities that cannot be   defined in terms of the other physical quantities.

3.The unit measurement of a base quantity is known as a base unit or SI unit.

Base quantity	Quantity Symbol	SI unit	Symbol
Lenght	l	metre	m
Mass	m	kilogram	kg
Time	t	second	s
Electric current	I	ampere	A
Temperature	T	kelvin	K

4. Derived quantities are physical quantities which are a combination of base quantities expressed as products or ratios.

Derived quantity	Express in derived quantity	Units
volume	l x l x l	m3
density		kgm−3
velocity		m s−1
force		N
Electric charge	l  t	C

5.  Standard form is a shorter method of expressing a very small or a

     very large number. The general standard form is written as:

A  x 10ⁿ 

where 1≤ A< 10 and ⁿ is an integer.

Hence, the distance between the Earth and the Sun

=150 000 000 000m

=1.5 x 10¹¹m

5.  Prefixes are used to represent physical quantities which  

have very large or small number values in SI units

Prefix	Symbol	Factor
Tera	T	1012
Giga	G	109
Mega	M	106
Kilo	k	103
Hecto	h	102
Deca	da	101
Deci	d	10-1
Centi	c	10-2
Milli	m	10-3
Micro	µ	10-6
Nano	n	10-9
Pico	p	10-12