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SCIENCE FORM 4CHAPTER 2: BODY COORDINATION
Body coordination is the adjustment of the body in response to whatever stimulus received by some parts of the body.There are two types of body coordination : nervous coordination and hormonal coordination.The central nervous system is the control centre of the body. This system consists of the brain and the spinal cord.The peripheral nervous system consists of the autonomic nervous system and the somatic nervous system.
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SCIENCE FORM 4The neurone is a basic unit of the nervous system. There are three types of neurone:
Sensory neurone- carries impulses from the receptor or sensory organ to the central nervous system.
relay neurone- connects sensory neurone with motor neurone.
motor neurone- carries impulses from the central nervous system to effectors, like muscles or glands.
Sensory neurone Relay neurone Motor neurone
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SCIENCE FORM 4Comparision between sensory neurone, relay neurone and
motor neurone.Characteristic Sensory neurone Relay neurone Motor neurone
Position of cell body
In the middle of neurone
At the centre of neurone
At the end of neurone
Length of axon Short Changes Long
Movement of impulse
From the sensory organ or the receptor to the central nervous system
From the sensory neurone to the motor neurone in the central nervous system
From the relay neurone going out from the central nervous system to the muscle or effectors
Function Carries impulses from sensory organ or receptor to central nervous system
Transmit impulses from sensory neurone to motor neurone
Transmits impulses from central nervous system to effector
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SCIENCE FORM 4The human brain consists of three parts:
cerebrum- controls the functions of sensory organs and voluntary actions.
cerebellum – control body balance and coordinates body movements.
medulla oblongata- control involuntary actions.
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SCIENCE FORM 4
Mitosis Differences Meiosis
Somatic cells Place occurs Testes and ovaries
One Number of cell division
Two
Two Number of daughter cells
Four
Same as parents,diploid (2n)
Chromosomal number of
daughter cells
Half the number of chromosomes of the parent (n)
Genetically identical to the parent cell
Genetic content Different from the parent cell and from one another.
CHAPTER 3: HEREDITY AND VARIATIONComparision between meiosis and mitosis
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SCIENCE FORM 4Comparison between continuous and discontinuous variation
Continuous variation
Differences Discontinuous variation
Difference is not obvious
Differences in characteristic
Difference is obvious and definite
Height, body weight, skin colour
Examples of variation
Blood group, type of fingerprint, ability to roll the tongue
Normal distribution
Shape of graph Discrete distribution
Genetic and environmental factors
Factors that cause variation
Genetic factor
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SCIENCE FORM 4CHAPTER 4: MATTER
Pure substances have a specific melting point (freezing point) and boiling point.Any impurity added to pure substance will raise the boiling or lower the freezing point of that substance.For example, water that is with salt will boil at a temperature higher than 100 C and will freeze at a temperature lower than 0C
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SCIENCE FORM 4CHAPTER 5: ENERGY AND CHEMICAL CHANGES
Exothermic reaction is a reaction that releases heat energy to the surroundings.Heat energy released from reactant to the surroundings causes the surrounding temperature to rise.Endothermic reaction is a reaction that absorbs heat energy from the surroundings.Heat energy absorbed by the reactant from the surroundings lowers the surrounding temperature.
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SCIENCE FORM 4CHAPTER 6: RADIOACTIVE SUBSTANCES
TheThe characteristics of radioactive radiation
RadioactiveradiationAlpha rays
Nuclei of heliumConsists of positively
charged (+) particles.
The penetrating power is low,
can be blocked by a sheet of
paper.
Beta raysConsist of high speed electrons, which are
negatively charged (-)The penetrating power is
higher, can be blocked by a thin sheet of aluminium
Gamma raysNeutral (in term
of electrical charges)
Consists of high power
electromagnetic waves.
The penetrating power is very
high, can only be blocked by a
thick lead or a thick concrete
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SCIENCE FORM 4CHAPTER 7: LIGHT,COLOUR AND SIGHT
Primary colours are colours which cannot be obtained from mixing other colours.There are three primary colour, namely red, blue and green.Secondary colours are colour produced by adding primary colours.There are three secondary colours, namely yellow, magenta and cyan.Addition of primary colours and secondary colours can produce white light.
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SCIENCE FORM 4CHAPTER 8: CHEMICALS IN INDUSTRY
An alloy is a mixture of two or more metals (like bronze and brass) or a metal with a small amount of non-metal (like steel)Examples of alloy are steel, pewter, bronze, brass and duralumin.Alloying can:
Increase the hardness of metalsPrevent corrosionImprove the appearance of metals
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SCIENCE FORM 5CHAPTER 1: MICROORGANISMS
Vector is an agent that carries diseases.Houseflies and mosquitoes are two main vectors that transfer pathogen to humans.Diseases like cholera and hepatitis A can be prevented if the population of houseflies is controlled.Dengue fever and malaria can be prevented is mosquito reproduction is prevented.Knowledge on the life cycle and behaviour of vectors can help us to eliminate them.
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SCIENCE FORM 5The lifeThe life cycle of a mosquito
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SCIENCE FORM 5The life cycle of a housefly
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SCIENCE FORM 5CHAPTER 2: NUTRITION AND FOOD
PRODUCTIONThe quantity of energy needed by an individual depends on the factors:
GenderAgeBody sizeWeatherPhysical activityHealth condition
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SCIENCE FORM 5Gender
Males need more energy than females because they are more active
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SCIENCE FORM 5Age
Young people need more energy than old people because they are more active
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SCIENCE FORM 5Body size
A bigger body needs more energy because the metabolic rate of those with bigger bodies are higher.
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SCIENCE FORM 5Weather
People in cold places need more energy to maintain their body temperature.
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SCIENCE FORM 5Physical activities
Active people or those doing laborious jobs need more energy.
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SCIENCE FORM 5Health condition
Sick people need more nutritious food to fight diseases as compared to healthy people.
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SCIENCE FORM 5CHAPTER 4: CARBON COMPOUND
Organic carbon compounds originate from living things. Examples: sugar, starch and cellulose.Inorganic carbon compounds originate from non living things. Examples: carbon dioxide and calcium carbonate.Hydrocarbon compounds are compound that are made up of only hydrogen and carbon elements.Petroleum, natural gas and coal are examples of natural resources of hydrocarbon
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SCIENCE FORM 5CHAPTER 5: MOTION
Comparision between speed, velocity and acceleration
SPEED VELOCITY ACCELERATION
Meaning Distance travelled within one unit of time
Rate of change in distance in a specific direction
Rate of change in velocity of a moving object
Formula Speed=distance
time
Velocity:
Displacement
time
Acceleration:
Final velocity-initial velocity
time
Unit Metre per second
Or ms¯¹
Metre per second or ms¯¹
Metre per second per second or ms¯²
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SCIENCE FORM 5Application of Bernoulli’s principle in aircraft
flight.Wings of aircraft have an aerofoil shape.The flow of air is faster at the top than that at the bottom of the aerofoil.According to Bernoulli principle, the top part of an aerofoil will have low pressure where the air flow is faster. At the bottom of the aerofoil where air flow is slower, the pressure is higher and will produces a lift force that pushes the wing upwards.
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SCIENCE FORM 5CHAPTER 6: FOOD TECHNOLOGY AND
PRODUCTIONAmong the effords conducted to increase the quality and quantity of food production include:
Usage of quality breedsUsage of modern technologyEducation and guidance to farmersResearch and developmentOptimum usage of land and water catchment
areas.Efficient management of land.
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SCIENCE FORM 5CHAPTER 7: SYNTHETIC MATERIALS IN
INDUSTRY
The properties of thermoplastics
Good electrical insulator
Low melting point causes it to soften easily
when hot and return to its original shape once cooled
Can be stretched and burned easily
The ability to mould repeatedly enables thermoplastic to be recycled
Colourless and transparent
Most thermoplastics materials dissolve in organic solvents
Resistant to most chemical substances such as acid and alkali
Did not have cross linkages between molecule
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SCIENCE FORM 5The properties of thermoset
The properties of thermoset
High melting point causes thermoset harden
when cooled and is unableto melt once again although heated at high temperature
Does not bend or burn easily
Can be moulded only once and thus, cannot be recycled
Do not dissolved in any organic solvent
Resistant to most chemical substances such as acid and alkali
Good electrical insulator
Harder, more shock and heat resistant compared
to thermoplastic
Have cross linkage between molecules
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SCIENCE FORM 5CHAPTER 8: ELECTRONICS AND COMMUNICATIONS
TECHNOLOGY (ICT)The properties of waves and their description
Property of waves Description
Wavelength The distance between two successive of waves
Wave frequency The number of complete waves generated in one second
Wave amplitude The maximum displacement of a wave from its original position (or equilibrium position)
Wave velocity The distance travelled by a wave in one second
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SCIENCE FORM 5
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SCIENCE FORM 5
THE END….GOOD LUCK !!!!