SCIENCE FORM 3




click the HEART to see the annimation of blood circulatory system!




TRANSPORT SYSTEM IN PLANT





EXCRETION

Your Urinary and How It work

urinary system - interactive 

What does your urinary system do? 





FORM 3 : REPRODUCTION

SEXUAL REPRODUCTIVE SYSTEM
                                        IN FLOWERING PLANTS


FLOWER PART
FUNCTION
Petals
Attract insects & animals to pollinate the flower
Sepal
Protect the flower when it is in the bud
Stamen
Male reproductive part of flower
Filament
Holds up the anther
Anther
Contains pollen grains
Pollen grains
Contains male gametes
Pistil
Female reproductive part of flower
Ovary
Protects the ovules
Ovule
Contains female gametes
Style
Holds up the stigma
Stigma
Receives the pollen grains
Nectary
Produce nectar



TYPES OF POLLINATION
There are 2 types of pollination:
  1. Self pollination
Transfer of pollen grain within the same flower or to another flower on the same plant

  1. Cross pollination
Transfer of the pollen grains to the flower of another plant of the same species
The advantages of cross pollination are:
a)      Provide more genetic variation in the offspring
b)      Produce offspring with better characteristics such as
i-                    High yield
ii-                   Better quality of flowers, seeds and fruits
iii-                 More resistant to disease
iv-                 Shorter maturing time of growth


 
3.  Pollinating agent
- Pollinating agents carry the pollen grains to the stigma of the flower.
- there are 3 main types of pollinating agents:
i) Animals – the pollen grains stick to their bodies and are transferred to the stigma of a same flower or the next flower they visit
examples: sunflower, durians

ii) Wind – pollen grains are carried from one flower to another by wind
examples: paddy, maize

iii) Water – water is the pollinating agent for many submerged aquatic plants
examples: Hydrilla , Elodea
-the differences between insects pollinated flowers and wind pollinated flowers are shown below:





characteristic
Insect pollinated
Wind pollinated
Flower size
big
Small
Petal colour
Bright
White or dull colour
Nectary
Produces nectar
Do not produce nectar
Smell
Fragrant
No smell
Stamen
Short filament & small anther
Long filament & big anther
Pollen grain
Few in numbers, big & sticky
Numerous, small & light
Stigma
Short & sticky
Long, feathery & exposed outside the flower
Style
short
long
receptacle
short
long


OBJECTIVE QUESTIONS

  1. The figure shows the process of ____________ _ .


 
A          self-pollination
B          cross-pollination
   C         germination
   D         fertilisation


2. The female and male gametes of flowering plants are located at the ___________ .

A          sepal and stamen
B          pistil and ovary
C         ovule and pollen grain
D         filament and anther
                                                                            
3.The figure shows the process of pollination
Where does the transfer of pollen grain take place?


A          P,R
B          P,Q
C         S,P
D         S,Q


4. Cross-pollination is better than self pollination because the offspring __________ .

I           produces more fruits
II          survives better under bad weather
III         is less resistant to diseases

A          I and II
B          I and III
C         II and III
D         I, II and III
                                                                                           
5.The figure shows a flowering plant.





Which of the following is the pollinating agent for this plant?

A          Insect
B          Bird
C         Wind
D         Water



6. The figure shows the flower of flowering plants



Which flowers are pollinated by insects?

A          P and Q
B          Q and R
C         R and S
D         P and R


7. A stamen is the male reproductive organ and pistil is the female reproductive organ of  flowering plants. Stamen consists of filaments and anthers while the pistil consists of stigma, style and ovary.

A male reproductive organ of flower consists of _______________ .

A          filament, anther and ovary
B          stigma, style and ovary
C         filament and anther
D         stigma, style and anther

 

PMR 2009 –Paper 2
1.(a)   Diagram 1.1 shows two plants, R and S from the same species.



                                                                                        Diagram 1.1
i) Sstate two advantages of using cross-pollination for breeding in agriculture
1.________________________________________________________________

2.________________________________________________________________                  [2 marks]

ii) Suggest one way to ensure only cross-pollination takes place in S
__________________________________________________________________                  [1 mark]

iii) State one reason for the answer in 1(a) ii)
____________________________________________________________________              [1 mark]

(b) Diagram 1.2 shows rose plants grown in an enclosed farm.

                                                                   Diagram1.2
i) Suggest one way to increase the cross-pollination in this farm
________________________________________________________________________       [1 mark]

ii) State one reason for the answer in 1 (b) (i)
________________________________________________________________________      [1 mark]

(c) Diagram 1.3 shows a honey bee feeding honey on a flower of a fruit tree.


Explain how this situation helps the farmer to increase the yield of fruits from his trees.
__________________________________________________________________________

__________________________________________________________________________  [2 marks]

SUGGESTED ANSWER

1. a)(i) to produce a healthier plant, to produce a new variety of plant

(a)(ii) remove the anther
(a)(iii) prevent self pollination
(b)(i) use bees
  (b)(ii) transfer the pollen grain from one plant to another (c) bee act as a pollination agent, increase the yield of fruit.

 


                       LAND AND ITS RESOURCES

In this topic you should know :

6.1 : Minerals in the Earth´s crust 


1. Minerals  are elements or compounds that are found in the Earth’s crust.
2. Gold ,Platinum,Silver and Mercury exist as elements.
3. Compounds are combinations of metals and non – metals ;
     with oxygen --- Oxides
     With sulphur --- Sulphides
     with carbon --- Carbonates

6.2 Reactions between Metals and Non- Metals                                                        
1. Reaction between metals and oxygen .
    (a) Most metals react with oxygen to form metal oxide .
           Metal + oxygen  ----- Metal Oxide                       
    
     For example :
         Magnesium + Oxygen  -----  Magnesium Oxide
             Zinc        +  Oxygen  ------  Zinc Oxide




 
2. Reaction between metals and sulphur
   (a) Most metals reacts with sulphur to form metal sulphide
          Metal  +  Sulphur   ---------    Metal sulphide
         
      For example :

        Magnesium  +  Sulphur    --------- Magnesium Sulphide
             Zinc     +    Sulphur    ------------  Zinc Sulphide 

6.3 :  Silicon Compound                                                                                              

  1. Silicon is the most abundant non-metal element in the earth´s crust .
  2. Silicon exists  compounds known as Silica and Silicates .
  3. Silica is a compound of silicon and oxygen ; also known as silicon dioxide.
Example of silica  are  sand , sandstones and flint.
  1. Silicates is a compound of metal , silicon and oxygen .
Examples of silicates are clay, asbestos and mica.
  1. Silicon compounds are very stable because they do not dissolve in water , do not  react with  acid and do not decomposed when heated.


6.4 : Calcium Compound 
     
1.    Calcium compounds naturally exists as limestones, corals, eggshell , marble
       and bone.
    2.  Calcium carbonate is made up of calcium , carbon and oxygen.        
  
3.    Properties of calcium carbonate :
(a)  Insoluble in water
(b)  It react with dilute acid to produce salt , water and carbon dioxide.


Calcium carbonate + Hydrochloric acid  ----- Calcium Chloride + Water + Carbon dioxide

            ( c ) When heated , it decomposes into calcium oxide and carbon dioxide .

   Calcium carbonate     --------    Calcium oxide + Carbon dioxide  

         

Calcium oxide + Water       ---------    Calcium hydroxide (solid)


(d)  When more water is added , the solid calcium hydroxide (slaked lime)
dissolve to form calcium hydroxide solution or limewater.

     6.5 :   Natural Fuel Resources  

 
    1.   Petroleum is a mixture of hydrocarbons. The various hydrocarbon compounds can
           be  separated through fractional distillation
2.   The different hydrocarbons can be distilled because they have different boiling
points. The lowest temperature of less than 25º C to the highest temperature of  more than 350ºC.
3.    The fractions of Petroleum fractional distillation in ascending temperature is
Petroleum gas ---Petrol---- Naphtha ---Kerosene--- Diesel --- Lubricating oil--- Fuel oil  --- Bitumen .  

 
Paper 1 : Objective Questions


1.         Gold, quartz and limestone are examples of minerals.
            Which of the following is a mineral?

A             Quartz
B             Nitrogen
C            Oxygen
D            Hydrogen

2.         Minerals are solid elements or compounds found naturally in the Earth’s crust.
           Where can you find minerals?

A             Outer space
B             Atmosphere
C            Deep ocean
D            Earth’s crust

3.         Calcium carbonate releases carbon dioxide and forms calcium oxide when heated.
            Name the product formed when calcium carbonate is heated.

A             Iron oxide
B             Iron sulphide
C            Calcium oxide
D            Calcium carbonate

4.         Silicate is a compound made up of silicon, metal and oxygen. Asbestos, jade, clay, mica and feldspar are examples of silicate.
            Which of the following is not a silicate?

A             Jade
B             Clay
C            Quartz
D            Asbestos



5.         Magnesium reacts faster when heated in oxygen than zinc and iron.
            Choose a metal which is most reactive.

A             Magnesium
B             Zinc
C            Iron

6.         Calcium carbonate is made up of different elements namely calcium, carbon and oxygen.
            How many elements are present in calcium carbonate?

A             One
B             Two
C            Three

7.         The table shows the composition of calcium silicate.

Mineral
Element composition
Calcium silicate
Calcium
X
Oxygen
            What is element X?

A             Silica
B             Silicon
C            Silicate

8.         The figure shows substance Q being heated. After a few minutes the lime water  
            turns chalky.



            What is substance Q ?

A             Aluminium oxide
B             Aluminium silicate
C            Calcium sulphide
D            Calcium carbonate

9.      Which of the following word equations is correct when metal sulphide is heated? 

A             Lead sulphide  ---- Lead oxide + sulphur
B             Copper sulphide ----- copper oxide + carbon dioxide
C            Iron sulphide ----- iron oxide + sulphur dioxide
D            Aluminium sulphide ---- aluminium oxide + oxygen


10.       The figure shows the apparatus set up to study the reaction of metals with oxygen. 3 asbestos papers are filled with metal powders A, B and C respectively.

 

From the observation, choose the most reactive metal .
                       

Types of metal
Observation
A
Burns quickly with white flame
B
Burns with a bright flame and spreads slowly
C
Glows and spreads slowly


11.      The figure shows the fractional distillation of petroleum


What are the products represented by X, Y and Z?


X
Y
Z
A
diesel
petrol
kerosene
B
petrol
kerosene
diesel
C
petrol
kerosene
bitumen
D
kerosene
diesel
bitumen





ANSWERS
1. A
2. D
3. C
4. C
5. A
6. C
7. B
8. D
9. C
10. A
11. B

CHAPTER 7: ELECTRICITY



7.1 Electrostatics


1. Electrostatics is the study of static electrical charges.


2. There are two types of electric charge: positive charge and negative charge.


3. Positive charges consist of protons and negative charges consist of electrons.


4. A neutral object has the same number of positively and negatively charged
particles.


5. An object that loses electrons becomes positively charged because there are
more protons than electrons.

6. The transfer of charged particles happens when two different substances are
rubbed. The charge formed by friction is known as electrostatic charge.



7. The Detection of Electrostatic Charge


Electrostatic charge can be detected by using an electroscope.

7.2 Electricity
1. Some sources of electrical energy are the solar cell, dry cell, wet cell, power generator, lithium ion battery and cadmium battery.
2. An electric current (I), is defined as the rate of flow of electrons.


3. The electrical force needed to move electrons between two points is called the
voltage (V) or potential difference between the two points.



4. The property of a materials that prevents or resists the flow of electrons
through the material is called the resistance (R).

7.3 Electric Current, Voltage and Resistance




Electrical
Current
Voltage
Resistance
Definition
Quantity of electric
charge that flows through a conductor
in
The potential
difference between two points in an electric
circuit
The opposition to the
flow of electric charge
Measuring
instrument
Ammeter
Voltmeter
Using Ohm's Law
R = V I
Symbol
I
V
R
Method of connection
Series
Parallel
Resistance of wire depends on:
length
diameter
type of metal



7.4 Relationship between current, voltage and resistance


1. Ohms Laws states that the current flowing through a conductor is directly
proportional to its voltage.

2. Ohm’s law is given by the following formula,

7.5 Parallel and Series Circuits
Series circuit
Difference in term
Parallel circuit



The electrical components are connected end to end
Method of connection
The electrical components are connected side by side
The current flows in one channel only
Number of channels
The current flows in more than one channel
The other bulbs will not light up
If one bulb burns out
The other bulbs will still light up
Same in every resistance
I = I1 = I2 = I3
Amount of current
Same as the total amount of current in every channel
I=I1 + I2 + I3
Same as the amount of
voltage through every bulb
V = VI + V2 + V3
Amount of voltage
Voltage is the same as the
voltage supply
V1 = V2 = V3 = V
Total resistance (R) is the same as total of all resistances R=RI+R2+R3
Amount of resistance
Total resistance (R) is calculated as follows:
1 = 1 + 1 + 1
R RI R2 R3
Does not last long
Lifespan
Lasts long
Increases if the number of cells increases
Current
Same even though the number of cells increases


7.6 Magnetism


1. Magnetism is a group of phenomena associated with magnetic fields.


2. The characteristics of a magnet are:


(a) A magnet has two poles the north and the south poles.
(b) The same poles repel, different poles attract each other.

(c) A free hanging magnet always points in the north-south direction.
(d) A magnet can attract iron, steel, cobalt and nickel.


3. A magnetic field is a field of force surrounding a magnetic body.




7.7 Electromagnetism


1 An electromagnet is a temporary magnet formed when an electric current is passed


Through a coil of conductor wire.


2 The current that flows through the conductor produces a magnet field around it


3 The direction of the magnetic field of a straight wire can be determined by using the


RIGHT HAND GRIP RULE.

 




a. The thumb represents the direction of the current flow


b. The curved fingers represent the direction of the magnetic field


4. The strength of a solenoid magnetic field can be increased by

a. increasing the number of turns in the coiled wire.
b. Inserting a laminated iron bar into the solenoid.

c. Increasing the current flow.


5. Electromagnets are used in loud speakers, electric bells, telephone receivers and telegraph machines.

6. The strength of a solenoid magnetic field can be increased by




d. increasing the number of turns in the coiled wire.
e. Inserting a laminated iron bar into the solenoid.

f. Increasing the current flow.


TRY THESE!




1. Underline the correct answer below to describe what electrostatics is.
(Electrostatic / Electricity) is the study of static electrical charges.
2. Underline the correct answer below to state the types of static electrical charges
a. Objects with the same type of charges (repel / attract) each other.
b. Objects with different types of charges (attract / repel) each other.
3. Underline the correct answer below to state the properties of static electrical charges.
a. A positively-charged object has more (protons / electrons) than (protons / electrons).
b. A negatively-charged object has more (protons / electrons) than (protons / electrons).
c. A (positively charge / neutral) object has the same number of protons and electrons.