NOTE FORM 2

By
Mohd Hanafiah B Said

HARAP MAAF, KERJA KERJA PEMURNIAN SEDANG GIAT DILAKUKAN

HARAP MAKLUM

1.1 TO STUDY THE STRUCTURE OF THE HUMAN 

1. Our skin serves as an organ for touch. It is richly supplied with nerve endings.
2. Covers the whole human body and is the largest human organ.
3. Receptors  sensitive  to  heat,  cold,  touch,  pain,  and  pressure  are  nerve  endings
sensitive to stimuli.
4. Skin is divided into the inner dermis and the outer epidermis.
5. Receptors are stimulated by external forces, send nerve impulses to the brain through
the spinal cord.
6. Some areas of the skin are far more sensitive than others. The degree of sensitivity
depends on:
a) the more receptors, the more sensitive that area is eg. Finger tips, tongue, lips
and neck.
b) The thickness of the epidermis -the thicker the epidermis, the less sensitive it is,
eg. back, upper arm, soles of feet, elbow

 

 

UNDERSTAND THE SENSE OF TASTE AND SMELL 

Relationship Between Smell And Taste Senses Relationship Between Smell And Taste Senses Relationship Between Smell And Taste Senses Relationship Between Smell And Taste Senses Relationship Between Smell And Taste Senses
1. The mouth cavity is connected to the nose cavity
2. Taste sense is influenced by smell sense.
3. Food do not taste as good if a person has a cold as the nose cavity is blocked by mucus and the 

    smell cells are not activated.
4. Smoking and liquor can affect the senses of smell and taste.

TO UNDERSTAND THE SENSE OF HEARING 

The  Human  Ear
1. Consists of outer, middle and inner ear
2. Sound vibrations travel down the outer ear, vibrate the eardrum and the ossicles
which are attached to oval window.
3. The movement of the oval window causes vibrations in the inner ear.
4. Sensory cells in the cochlea receive the stimulus.
5. Impulses travel to the brain through the auditory nerve to be analysed.

UNDERSTANDING THE SENSE OF SIGHT
(THE HUMAN EYE)

1. The human eye is spherical and held in the eye socket in the skull by 3 pairs of muscles.
2. The  six  muscles  move  the  eye  in different directions.
3. In man, the iris contains pigment and is therefore coloured. Dark skinned people have  

    brown  orblack  iris  while  light skinned people have grey, blue or green ones. In albinos, 

    it appears red.
4. The images formed on the yellow spot on the retina are inverted, diminished and real.
5. In bright light (small pupil), In dark places (large pupil)
6. Eye focused on near objects:-
• ciliary muscles contract
• suspensory ligament relaxes
• lens become shorter and thicker.
7. Eye focused on far objects:-
• ciliary muscles relax
• suspensory ligament contracts
• lens become longer and thinner

TO SHOW THAT LIGHT TRAVELS IN A STRAIGHT LINE 

1. Light is a form of useful energy that can be detected by our eyes and can be transferred
from one place to another.
2. Does not need a medium to travel in, can travel in a vacuum.
3. Speed of light in vacuum is 300 million metres per second (3 x 10 8  ms -1 )
4. Light travels at different speeds in different media. In the same medium, it travels in
straight lines.
5. Light energy travels from the sun in the forms of waves, takes about 8 minutes to
reach the earth.
6.  Essential for green plants to manufacture food.
7. Without sunlight, the whole food chain would break down and life on earth would
cease to exist.

TO EXPLAIN FORMATION OF SHADOWS AND ECLIPSES 

1. Shadows are formed when light is blocked by opaque objects.
2. Light cannot bend.
3. A region of darkness formed behind the opaque object is a shadow.
4. The type of shadow formed depends on the sizes and position of the light source and
the object.
5. The  dark  centre  of  a  shadow  is  the  umbra  surrounded  by  a  partial  shadow,  the
penumbra.
6. A solar eclipse - the sun casts a shadow of the moon on the Earth. The sun, the moon
and the Earth are in a straight line with the moon in between. Total solar eclipse -
umbra region experiences total darkness for a few minutes.
7. Lunar eclipse - the sun casts a shadow of the Earth on the Moon. The sun, the Earth
and the moon are in a straight line, with the Earth in between. When the moon is in the
umbra region, it cannot be seen on Earth.

 LIGHT TO EXPLAIN REFLECTION OF LIGHT 

1. Light travelling in a straight line bounces back or reflects when it strikes the surfaces
of another medium. The amount and direction of the reflected light depends on the
nature of the surface it strikes.
2. A parallel light beam will be reflected as a parallel light beam on a smooth surfaces.
3. Non parallel light beams striking a smooth surface will produce diverging or converging
reflected rays.
4. Parallel rays striking a rough surface are scattered or diffused and no images are
formed.
5. Light striking a smooth surface at a right angle will be reflected along the same path
called the normal.
6. Laws of reflection
a) angle of incidence = angle of reflection
b) incidence beam, normal and the reflected beam all lie in the same plane.
7. Image formed by a plane mirror, is behind the mirror, virtual (cannot be formed on a
screen), same size as the object, upright but laterally inverted (right side appears as
the left).

 

TO EXPLAIN REFRACTION OF LIGHT BETWEEN MEDIUMS OF DIFFERENT DENSITIES

1. Refraction is the bending of light from its original path.
2. Result of a change in the speed of light travelling from one transparent medium into
another of a denser medium.
3. From a less dense medium (air) into a denser medium (water), its path or refracted ray
bends towards the normal due to slowing down of the speed of light.
4. From a denser medium (air), into a less denser medium the refracted ray bends away
from the normal due to increase in the speed of light.
5. Effects and consequences of refraction
a) shallower depth of water in a swimming pool -(apparent depth)
b) Illusion of fish at a shallower depth in an aquarium.
c) Straw in a glass of water looks bent, shifted and magnified.
d) Dispersion of white light
e) Stars at night seen higher due to air in higher places being less dense than air at
sea-level. Light from the stars bends when entering denser air nearer the Earth’s
surface.

TO SHOW SHORT-SIGHTEDNESS, LONG SIGHTEDNESS,OPTICAL ILLUSIONS, STEREOSCOPIC AND MONOCULAR VISION'

1. Short Sightedness
(Hypermetropia)
a) Can  see  near  objects  clearly  but
distant objects are blur
b) Eyeball too long, eye lens too thick
c) Image formed behind the retina
d) Corrected  by  wearing  concave  or
diverging lens
2. Long Sightedness (Myopia)
a) Can see distant objects clearly but
near objects are blur
b) Eyeballs too short, eye-lens too thin
c) Image formed in front of the retina
d) Corrected  by  using  convex  or
converging lens
3. Optical Illusions
a) caused by wrong interpretation by
the brain of what we see
b) caused by limitation of sight
4. Stereoscopic Vision And
Monocular Vision (for survival
of animals)
a) Stereoscopic or binocular vision
• eyes set in front (monkeys, tigers,
owls, people)
• able to judge distances accurately
• able to see 3- dimensional objects
clearly
•  helps animals to hunt well
b) Monocular vision
• Eyes set at the sides (deer, rabbit,
fish, pigeon)
• Cannot judge distances accurately
• A much wider field of vision
• Can detect approaching enemies
from side or rear

TO EXPLAIN THE PRODUCTION OF SOUND AND HOW SOUND TRAVELS 

1. Sound is produced by vibrating objects.
2. Travel in the form of waves.
3. Needs a medium to carry its vibrations as it travels from one place to another.
That  is  why  sound  cannot  travel  in  a  vacuum  as  a  vacuum  does  not  have
molecules.
4. Sound travels through materials with densely packed molecules such as metals.
Sound travels fastest through solids followed by liquids and gases which have
the least densely packed molecules.
5. Speed of sound in air is 330 metres per second (330 ms -1 ), in metals - 5000 m/s
and in water - 1500 m/s, much slower than the speed of light.
6. Sound can be reflected. Hard and rough surfaces (eg. wood, concrete) are good
sound reflectors. Soft and smooth surfaces (eg. cotton, carpets, curtains, cushion
covers) are good sound absorbers.

SES IN PLANTS TO IDENTIFY STIMULI AND RESPONSES IN PLANTS 

1. Plants respond to specific stimuli like light, water, gravity and touch
2. Responses in plants are divided into:
a) Tropisms
•  Phototropism (leaves and branches respond to light)
•  Geotropism (roots respond to gravitational pull)
•  Hydrotropism (roots respond to water)
•  Tigmotropism (respond to touch)
b) Nastic movement - caused by temperature differences, touch and the degree
of light.
3. A clinostat turns to expose all parts of a plant to an equal amount of light to enable it
to grow healthily.

THE CLASSES OF FOOD (CARBOHYDRATES) 

1. Most important source of body energy.
2. Complex compounds of carbon, hydrogen and oxygen elements.
3. Simplest  kinds  of  carbohydrates  (sugar)  -  glucose  (grapes),  lactose  (milk),
sucrose (sugarcane) and maltose (malt).
4. Excess carbohydrates stored as fat, used when carbohydrate intake is low.
5. Sources - rice, oats, bread, wheat, potatoes, yams and tapioca.

THE CLASSES OF FOOD (PROTEIN) 

 1. Large, insoluble molecules of carbon, oxygen, hydrogen and nitrogen elements.
2. Produce enzymes, hormones and haemoglobin.
3. Make up muscles and tendons.
4. Build new cells (protoplasm).
5. For growth and repair of worn-out body parts.
6. Supply some energy.
7. Sources – animal protein :  meat, fish, eggs, cheese, milk
    – plant protein   :  lentils, nuts, beans.
8. Animal protein is a first class protein because it contains all the amino acids.
9. Deficiency of protein causes kwashiorkor (loss of body fat).

THE FUNCTION OF ROUGHAGE AND WATER 

Roughage
a) Fibrous, indigestible material
b) Ego lignin, pectin, cellulose
c) Expelled together with faeces
d) Helps movement of food in the alimentary canal
e) Activates movement of intestinal muscles
Water
a) Water is lost from our body through urine, sweat and water vapour in respiration.
b) Needed to be replaced by drinking water and eating fruits and vegetables.

 THE CLASSES OF FOOD (FATS) 

1. Contain stored chemical energy.
2. An oil is a fat that is liquid at room temperature and solidifies into fat in a fridge.
3. Twice the amount  of energy stored in fats than in a similar amount of carbohy-
drates.
4. Acts as a solvent for vitamin A, D, E and K.

THE CLASSES OF FOOD (VITAMINS) 

 

THE CLASSES OF FOOD (MINERALS) 

1. Our body needs small amounts of mineral salts to keep it in good, healthy, working
order.
2. Some of the minerals are needed in really minute quantities while others like cal-
cium, phosphorus, potassium, sulfur, chlorine, sodium, magnesium and iron are
needed in larger quantities.

TO UNDERSTAND TO UNDERSTAND
THE DIGESTIVE SYSTEM IN MAN 

1. Food provides us with energy but the energy stored in food cannot be immediately
released into the bloodstream into the cells of our body.
2. The large, insoluble, indiffusible food molecules must be broken down into smaller
soluble diffusible ones by digestion, a chemical reaction to break down food by the
action of enzymes which are produced by our body for bringing about or speeding
up specific chemical reactions.
3. Digestion is also speeded up with the help of our teeth.
4. The digestive system starts in the mouth and ends with undigested food leaving the
anus as faeces.

TO CLASSIFY ANIMALS - VERTEBRATES T(REPTILES AND BIRDS) 

Reptiles
1. Live on land (except turtles and water snakes)
2. Have dry, scaly skin to prevent water loss.
3. Usually four - legged and clawed (except snakes)
4. Breathe through lungs and are cold - blooded (poikilothermic)
5. Internal fertilisation, lays shelled eggs.
6. Have ear-drums, no external ears.
7. One type of teeth only, sharp and cone-shaped
Birds
1. Live on land, most of them can fly. Cannot fly - hen, duck, ostrich, penguin, turkey.
2. Body covered with feathers
3. Fore limbs are modified into wings.
4. Have horny toothless beaks for feeding.
5. Breathe through lungs and are warm blooded (homoiothermic).
6. Internal fertilistion, lay eggs with hard, chalky shells.
7. A pair of wings and a pair of scaly feet.

TO CLASSIFY ANIMALS - (MAMMALS)

1. Live mostly on land except whales and dolphins.
2. Breathe through lungs and are warm-blooded (homoiothermic).
3. Possess mammary glands to suckle their young.
4. Have hair or fur on their skin.
5. External ears, sweat glands and various types of teeth.
6. Carry out internal fertilisation, give birth to young (except platypus, anteater which
lay eggs)

TO CLASSIFY ANIMALS -(FISH AND AMPHIBIANS)

Fish
1.  Live in fresh water or in the sea.
2. Stream-lined body to enable easy movement in  water.
3. Breathe through gills, cold-blooded (poikilothermic)-body temperature changes
according to the temperature of surrounding).
4. Body covered with slippery scales.
5. External fertilisation, usually lay eggs.
6. Uses lateral line to detect external stimulus.
7. Fins used for swimming and balancing.
Amphibians
1. Early stage - live in water, adult lives on land and in water.
2. Breathe through skin and lungs (for adults), through gills for tadpoles.
3. Have moist skin without scales, feather or hair.
4. Cold blooded (poikilothermic).
5.  Webbed feet.
6. Possess ear-drum without external ears.
7. External fertilisation, lay eggs without shells.

CLASSIFY  OF INVERTEBRATES 

Arthropods
• Lobsters, crabs, barnacles – live mainly in water, two pairs of antennae, hard outer
skin (exoskeleton)
• Spiders, scorpions, ticks, mites – four pairs of legs, no compound eyes.
• Millipedes – two pairs of legs on each body segment.
• Centipede – one pair of legs on each body segment.
• Insects – form 90% of the arthropods, three pairs of jointed legs, a pair of compound
eyes,  adults  have  wings,  three  main  body  parts  -  head,  thorax,  abdomen  (eg.  ant,
praying mantis, fly, bee, mosquito, butterfly)
Annelids
•  Segmented worms (leech, earthworm)
Flat worms
• Flat, unsegmented bodies
Round worms
• Round, unsegmented bodies
• With mouth and anus
Cnidarians (coelenterates)
• Attack prey with tiny stinging tentacles (jellyfish, sea anemone)
Echinoderms
• Spiny skins (starfish, sea urchin)
Molluses
• Soft bodies usually protected by hard shells, unsegmented, (snail, scallops, octopus)

FLOWERING PLANTS ( DICOTYLEDONS AND MONOCOTYLEDONS ) 

Dicotyledons
• Vein arranged in a network - reticulate or net veins.
• Two seed leaves or cotyledons.
• Usually have hard woody stems.
•  A main root with side roots.
• Flower petals often occur in  2' s, 4’s or 5’s
Monocotyledons
• Several main veins running parallel to one another
• One seed leaf or cotyledon.
•  Soft, non-woody stems.
• Fibrous roots.
• Flower petals occur in 3’s

CLASSIFICATION OF PLANTSERING ) ( NON FLOWERING )

Algae
• grow in water or damp soil
• No leaves, stems or real roots
• Unicellular (pleurococcus)
• Multicellular  (spirogyra, seaweed)
• Carry out photosynthesis, has
chlorophyll
Fungi
• grow in damp areas
• unicellular (yeast)
• multicellular (mucor, mushroom)
• No leaves, stems or real roots
• No chlorophyll, obtains food from
other palnts
• Reproduce by spores
Moss
• grow in damp places with sunlight
• has chlorophyll to carry out
photosynthesis
• usually has no stems or roots
• found in damp and shaded areas
• has leaves, stems and real roots
• has chlorophyll to carry out
photosynthesis
• reproduce by spores
• are epiphytes
- attach onto the host plant but do not
  harm them as they can make their
  own food

TO SHOW INTERACTION BETWEEN ORGANISMS  ( COMMENSALISM ) 

1.  Remora fish and shark
Commensalism is the relationship in which the remora fish attaches itself to a
shark and feeds on food scattered by the shark. The shark neither benefits from the
remora fish nor is harmed by it.

COMMENSALIM

Relationship between two kinds of organisms in which one benefits while the other
neither benefits nor is harmed by it.

TO EVALUATE INTERACTIONS OF ORGANISMS IN MUTUALISM ( SYMBIOSIS ) 

Rhizobium and the pea plant
Rhizobium bacteria in the nodules of the roots of the pea plant converts atmospheric
nitrogen into nitrates and supplies it to the pea plant. The pea plant supplies the rhizobium
bacteria with sugar for energy.
Fungus and algae
A lichen, a combination of an alga and a fungus living together. The alga provides the
fungus  with  food  by  photosynthesis  while  the  fungus  provides  support  by  making
materials needed by the alga.
Oxpeckers and large animals
Oxpeckers are birds that peck ticks or blood-sucking insects on the skin of large animals.
The large animals provide the oxpeckers with food while the oxpeckers get rid of pests
on the animals.
Clown fish and sea anemone
The sea anemone provides shelter and protection for the clown fish. The clown fish brings
food and lures larger fish to its stinging tentacles.)

MUTUALISM (SYMBIOSIS) 

Interaction between two different organisms that live together and both organisms
benefit from each other.

INTERACTIONS BETWEEN LIVING  ORGANISMS ( PARASITISM )

1. Relationship involving two organisms, the parasite and the host.
2. The parasite, eg. ticks, fleas, mosquitos, leeches and roundworms live and suck the
blood of the host eg. dogs, people and other animals.
3. The removal of blood brings harm to the animals and people,
4. Bacteria causing cholera and tuberculosis are parasites that harm our body.
5. Bracket fungi - parasites that draw water and minerals from the tree they live on.
6. The Rafflesia plant in southeast Asia, is a parasite, growing on and absorbing food
from the roots of woody plants.

TO EXPLAIN WHAT PRODUCERS ARE CONSUMERS AND PREDATORS 

Food Chain
1. Food relationship among organisms in an ecosystem, every plant and animal is called
a link.
2. Energy is consumed and transferred.
3. All energy comes from the sun.
4. Food producers
• Green plants which make food to provide for the rest of the organisms in the food
chain.
5. Consumers
• Animals that eat plants and other animals.
a)  Primary consumer – herbivore feeding directly on plants.
b)  Secondary consumer(predator) – carnivore feeding on primary consumers.
c)  Tertiary consumer (predator) – carnivore feeding on secondary consumers.
6. Since energy is lost along a food chain, most or all the energy would have been lost
by the time the food chain reaches its fourth or fifth line.

TO IDENTIFY PRODUCERS, CONSUMERS AND DECOMPOSERS

Producers
• Green  plants  trap  the  energy  of  the  sun  during  photosynthesis  to  produce  their
own food.
Consumers
• Herbivores and carnivores which feed on plants or animals to obtain energy.
Decomposers
• Such as scavengers (eg. Vultures, hyenas, crows), fungi and bacteria which feed
on  dead  plants  and  animals  and  break  down  the  dead  remains  into  simpler
substances, such as compounds of carbon and nitrogen which are released back
into the soil or air.
• Life  in  ecosystem  does  not  end  when  plants  and  animals  die.  The  food  chains
continues with the remains of dead plants and animals serving as food for another
important  class  of  organisms  living  in  the  same  ecosystem.  They  are  called
decomposers.
• Decomposers play an important part in the carbon and nitrogen cycles. They release
the nutrients trapped in the bodies of dead organisms so that these nutrients can be
recycled.

TO COMBINE A FEW FOOD CHAINS TO FORM  A FOOD WEB

1. Many animals eat more than one type of food.
2. Each animal or plant can be eaten by different animals.
3. A network of interconnected food chains form a food web in a natural ecosystem.
4. Food webs maintain the balance of populations of animals and plants.
5. Organisms are dependent on one another for survival.
6. Living things, other than green plants, obtain their energy from the food they eat.
7. A food chain shows how energy, in the form of food, is transferred from one organism
to another.
8. Not all the digested food will be converted to chemical energy stored in an animals
body. Some will be converted into heat which will be lost to the surroundings.
9. At every link in a food chain, energy is lost to the surrounding and the amount of
energy reaching the end of the food chain is only a small fraction of the amount of
energy at the beginning.

TO RELATE THE FOOD CHAIN AND PYRAMID NUMBER TO ENERGY FLOW

1. Approximately 90% energy is lost during transfer of food from one link/level to
another.
2. Highest energy loss - transfer from producers to primary consumers.
3. Less energy loss in a shorter food chain.
4. Energy loss from plant (producer) to rabbits (primary consumer)
=   10000 - 1000
x 100%
        10000
=   9000 x 100%
      10000
=   90%

TO DETERMINE THE FACTORS  NEEDED FOR PHOTOSYNTHESIS NEEDED FOR PHOTOSYNTHESIS

Photosynthesis is the process by which green leaves of a plant use energy from the
sun (absorbed by the green pigment chlorophyll), carbon dioxide and water to produce
food (glucose).
Diagram 1 : Carbon dioxide
a) The burning candle removes oxygen and replaces it with carbon dioxide.
b) The dish of caustic soda or limewater absorbs any carbon dioxide present. Starch
will only be found in the leaves of the plant in the bell jar with the lighted candle, as
carbon dioxide is present.
Diagram 2 : Chlorophyll
In variegated leaves, only the green areas that contain chlorophyll will contain starch.
Diagram 3 : Sunlight / Light
Only the part of the leaf which has been exposed to sunlight will contain starch.