Ramalan Esei 2011

8/3/2019 Ramalan Esei 2011

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CHAPTER 3: HEREDITY AND VARIATION

7 Study the following statement.

There are two different shapes in the ear lobes of the students in a class.

(a) Using the student population in a class, suggest a hypothesis to study the above statement.

[1 mark]

(b) Describe an experiment in your classroom to test your hypothesis according to the following

criteria.

Aim of experiment [1 mark]

Identification of variables [2 marks]

List of apparatus and materials [1 mark]

Procedure [2 marks]

Tabulation [1 mark]

Analysis of data [1 mark]

Conclusion [1 mark]

ANSWER

(a) The shape of the ear lobe is a discontinuous variation which can be clearly classified into the free ear

lobe or the attached ear lobe.

(b) Aim: To study the shape of the ear lobe among the pupils.

Variables that are

(i) manipulated: different students in the class room(ii) responding: type of ear lobe

(iii) constant: normal humans

List of apparatus and materials: number of students in the class, figure of the shape of ear lobe

Procedure:1. Group the pupils in pairs.

2. Based on the figure of the shape of ear lobe, determine the shape of the ear of their friend.

3. Record the results in the table below.

Tabulation:

Shape of ear lobe Attached ear lobe Free ear lobe

Tallying

Number ofoccurrences

Analysis of data: Draw a bar chart of number of occurrences vs shape of ear lobe.


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Conclusion: The shape of ear lobe is discontinuous variation.

9

(a) The figures (a) and (b) show the formation of twins. Name the types of twins and state three

differences about the types of twins

[4 marks]

(b) A normal married couple wishes to have a baby boy. Explain the mechanism of sex determination

of a baby.

Your answer should includes the following

Identify which gamete could determine the sex of a baby

Clarify the chromosomes which determine baby boy

Draw the genetic chart for the sex determination in the baby

The percentage of getting a baby boy for the couple.

[6 marks]


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ANSWER

(a)

Figure (a) Figure (b)

Identical twins Non-identical twinsOne single ovum is fertilized by one

sperm to form one zygote, then divides

into two zygotes

Two ova are fertilized by two sperms,

forming two zygotes

Two foetuses sharing one placenta Two separate placentas, one for each foetus

Both have similar genetic content Both have different genetic content

(b) The father's sperms determine the sex of a baby.

A baby which inherits a Y chromosome from its father, will be a boy. If it inherits a X chromosome from

its father, it will be a girl.

The percentage of getting a boy is 50%.

10 (a) Define mutation and mutagen.

Describe two factors that cause mutation.

[4 marks]

(b) The figure below shows mutation which happens in the body cell of human.

Study the abnormalities caused by mutation above. Explain how you can built a concept based onthe information in the figure above.


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Your explanation of the concept should include the following:

Identify two common characteristics [2 marks]

Develop initial concept [1 mark]

Give another example and a non-example in relation to the concept [2 marks]

Explain the actual concept [2 mark]

ANSWER

(a)

- Mutation is a change in the genes or chromosomes that can alter the original traits of organisms.

- Mutagen is a substance or radiation that can induce or cause mutation.

- Nuclear radiation such as alpha, beta, gamma and harmful ray can penetrate the nucleus of a cell

and change the structure of the genes and chromosomes.

- Chemicals such as mustard gas, benzene and dioxins can react with DNA in the chromosomes

(b)

Common characteristics- Additional or deletion of one chromosomes in the human body cell compare to the normal human body

cell.

- The difference in the number of chromosomes occur during meiosis to produce gametes with eithermore or less the number of chromosomes

Initial concept

- The change of the number or the structure of chromosomes is called chromosome mutation.

Other example

- Klinefelter's syndrome

Non-example

- Albinism / colour blindness / sickle cell anaemia

Actual concept

- Chromosome mutation is the result of the changes in the number or structure of chromosomes

11 (a) State two advantages and two disadvantages of genetic research to humans.[4 marks]

(b) A local Subang 6 papaya fruit is big but is less favourable to consumers.

Explain how MARDI solves the problem in increasing the consumption of local fruit.Your answer should include the following:

Identify the problem [1 mark]

Clarification of the traits of local papaya fruit and imported variety. [2 marks]

Name the solving method. [2 marks]

State the favourable trait of the product. [1 mark]

ANSWER(a) Advantages :1. genetic research has produced better medicines and vaccines for medical treatment.

2. genetic research has improved the quality of crops and livestock.

Disadvantages:1. genetic research may lead to extinction of species as new varieties replace them.

2. genetically modified food may be harmful to human health.

(b)


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- The local papaya is less favourable to the consumer.

- The traits of a local papaya are its big size, less sweet taste and has average thick flesh.

- The traits of an imported variety are its fragrant smell, sweetness and small size when plantedlocally

- Selective breeding is done between Local Subang 6 papaya and Hawaiian Sunrise Solo papaya

to produce a new variety named Eksotika Malaysia.- Eksotika Malaysia is sweet, smells fragrant with thick fresh and is average in size.

CHAPTER 7 : LIGHT, COLUR AND SIGHT

18 Study the following statement.

When white light is shone on two different primary coloured filters, no coloured light passes

through, but when white light is shone on two different secondary filters, a certain coloured light

passes through.

(a) Suggest a hypothesis to investigate the above statement.

[1 mark](b) Using a red filter, a blue filter, a magenta filter, a yellow filter and other apparatus, describe an

experiment to test your hypothesis in (a) based on the following criteria;



List of apparatus [1 mark]

Procedure [4marks]

Tabulation of data [1 mark]

ANSWER

(a) A primary colour filter only enables its coloured light to pass through it and to absorb all other colour

lights but a secondary colour filter enables its colour and the primary colour lights that form it to pass

through it.

(b) Aim of the experiment: To study absorption / subtraction of coloured light by a primary filter.Variables that are:

(i) manipulated : the colour filter used

(ii) responding : the colour on the white screen

(iii) constant : white light from ray box


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Apparatus: Light box, glass prism, a red filter, a blue filter, a magenta filter, a yellow

filter and white screen.

Procedure:

1. The apparatus as shown above is set up.

2. The light box is switched on. The position of the white screen is adjusted so that the spectrum of

white light illuminats it.

3. Two different colour filters (primary or a secondary as shown on the table below) are placed in

the path of the light beam at P and Q.

4. The colours that pass through both filters and illuminate the screen are observed.

Tabulation of data:Filter P Filter Q Colours on screen

Red Blue No colour

Red Magenta Red

Red Yellow Red

Blue Magenta Blue

Blue Yellow No colour

Magenta Yellow Red

19 (a) Compare the image formed by a convex lens and a concave lens.[4 marks]

(b) The figure below shows several characteristics formed by an optical apparatus.

Study the characteristics of the image formed. Explain how you can determine the apparatus used

and the phenomenon that occurred in the formation of the image based on the information in the

figure above.

Your explanation of the phenomenon should include the following:

Identify two criteria in the formation of the image

Identify the apparatus and develop the phenomenon

Give other example and non-examples of the characteristic of the image

Explain the Law of the phenomenon.

[6 marks]


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ANSWER

(a)

Properties of the image Convex lenses Concave lenses

Real or virtual Real if the object distance is u >f. Virtual

if the object distance is u


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The thickening and thinning

of eye lens is controlled bythe ciliary muscle that

changes the focal length of

the eye lens

Focusing method The camera lens moves

forward and backward byadjusting the focus adjuster,

which changes the distance

between the lens and the

film.Light enters the eye throughthe pupil. The size of the

pupil is controlled by the iris

which controls the amount oflight which enters the eye.

Controlling theamount of light

that enters.

Light enters the camerathrough the aperture. The

size of the aperture is

controlled by thediaphragm. The shutter also

controls the period of time

the light enters the camera.

(b)

Problem statement: To observe a distant object.

Name of the device built: Telescope

Name the apparatus needed:- Two convex lenses; one with a long focal length and the other one with a short focal length.

The arrangement of the apparatus- The long focal length convex lens is used as an objective lens to focus parallel light rays

from the distant object at its focal point.

- The short focal length convex lens is used as the eye lens and is adjusted so that the imagefrom the objective lens is at the focal point of the eye lens.

CHAPTER 5 - Motion

A moving heavy vehicle has higher momentum

Based on the statement above, suggest a hypothesis.

[1 mark]

(b) Using four trolleys, an inclined plane, a wooden block, plasticine and other apparatus,describe an experiment to test your hypothesis in (a) based on the following criteria:

(i) aim of experiment [1 mark]

(ii) identification of variables [2 marks](iii) list of apparatus and materials [1 mark]

(iv) procedure [4 marks]

(v) tabulation of data [1 mark]ANSWER :

11

(a) Hypothesis: The bigger the mass of moving object is, the higher the momentum.

(b) Aim of experiment: To study the relationship between momentum and the mass of movingobject.

Variable that is

(i) constant : the gradient of inclined plane(ii) manipulated : Mass of the trolley

(iii) responding : the distance of the trolleys stop


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List of apparatus and materials : trolleys, an inclined plane, a wooden block, plasticine and a

metre ruler.

Procedure:

1. The apparatus are arranged as shown above.2. Trolley X is released to go down the inclined plane and collide with trolley Y

3. Trolley X and Y are stuck after the collision and move together

4. The distance where the trolleys stop from the spot of collision is measured and

recorded.

5. The experiment is repeated with two trolleys at X position and three trolleys at Xposition respectively to collide with one trolley on Y position.

Tabulation of data

Number of trolleys Distance the trolleys stop

1

2

3

A big ship is made of a mixture of iron. The figures above show that a piece of iron

sinks into the sea whereas a big ship floats on the sea.Explain why.

[4 marks]


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A student makes a simple hot air balloon model as shown above for his science project.

He finds that his model could not fly.

Explain how to make his hot air balloon fly.Your explanation should include the following

Problem statement

State the concept and principle used Solving methods

[6 marks]ANSWER :

12(a)

Iron Ship

A piece of iron has a small volume,

thus the mass divided by volume

produces a higher density

The iron pieces in the ship are moulded into a

shape with a large volume of empty space at the

centre. The density of the ship becomes smaller.

The weight of water displaced is less

than the weight of the piece of iron.

Therefore, the iron sinks

The big ship displaces a large volume of water

where the weight of the water displaced is the same

as the weight of the big ship. Therefore the big shipfloats.

(b) Problem statement: The hot air balloon could not fly.

Concept used:

1. The hot air inside the balloon is less dense than the cool air outside.

2. The upthrust of the hot air balloon must be more than the weight of the balloon.3. The principle used is Archimedes' principle.

Solving methods:

4. Increase the size of the balloon to displace more cool air by the hot air inside the balloon.5. A bunsen burner is lighted at the bottom of the balloon to heat the air inside the balloon.

CHAPTER 6 Food technology and production

Processed food can last longer than non-processed food if left exposed to open air

Based on the statement above, suggest a suitable hypothesis.

Using a fresh non-processed milk, a boiled milk, a pasteurised milk and other apparatus,

describe an experiment to test your hypothesis in (a) based on the following criteria:



List of apparatus and materials [1 mark] Procedure [3 marks]

Tabulation of data [1 mark]

Conclusion [1 mark]

ANSWER :

13(a) Hypothesis: Processed food can last longer than non-processed food if left exposed to

open air.


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(b)

Aim : To identify the processed food that can last longer than non-processed food.

Variable that is;

(i) manipulated : the method of processed milk

(ii) responding: the condition of the milk(iii) constant: the volume of milk

List of apparatus and material: fresh non-processed milk, boiled milk, pasteurised milk, 3beakers, measuring cylinder

Procedure:

1. Three sterile beakers are prepared. Beaker A is filled with fresh non-processed milk, beaker

B is filled with boiled milk and beaker C is filled with pasteurised milk.2. The beakers are left in the open air for one day.

3. Observe the condition and the smell of the milk after one day and record in the table below.

Result: Beaker Observation

A

B

C

Conclusion:

Non-processed milk becomes rotten faster than boiled and pasteurised milk. Pasteurised milklasts longer than fresh non-milk and boiled milk.

The world population growth is much faster than the production of food. Explain how the

property of quality breeds can help to increase the production of food.

A vegetable farmer found his farm is no longer productive and is having problems with apest on his farm.

Explain how the farmer on his farm can overcome his problems on his farm.

Your answer should include the following;


Clarification of the problem [1 mark]

Solving methods [3 marks] Choose the best method and explain your choice [1 mark]

ANSWER :

14

(a) Property of quality breeds:

(i) high quantity of production(ii) high quality of production


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(iii) short production period

(iv) high resistance towards disease and pest

(b)

Identify the problem The farmer's farm is no longer productive and

is attacked by a pest.Clarification of the problem The soil is not fertile anymore due to intensive

use by certain kind of plant.

The pest has formed a high resistance towards

the pesticide used.

Solving methods Crop rotation to regain the fertility of the soil.

Mixed crops to regain the problem of the pest

and at the same time can regain the fertility ofthe soil.

Integrated system that is to rear poultry

together with plants.

Best method Mixed crops to reduce the problem of the pest,and at the same time can regain the fertility ofthe soil.

CHAPTER 8- Electric and information and communication technology

Study the following statement.

The brightness of a bulb varies with the number of resistors in a circuit.

19 (a) Suggest a hypothesis to investigate the above statement.[1 mark]

(b) Using three resistors, a bulb and other apparatus, describe an experiment to test yourhypothesis in (a) based on the following criteria;



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No. of resistor Brightness of bulb

3

2

1

Conclusion:As the number of resistors decreases, the brighter the bulb is. Hypothesis is acceptable.

20 (a) A radio wave is used in long distance communication. Give four reasons why a radio

wave is used in information communication.

[4 marks]

(b) The table below shows types of radio waves used in radio communication.

Local radio broadcasts Long Wave with low frequency

Radio broadcasts across continent Short Wave with high frequency

TV Astro broadcasts Microwaves

Study the information in the table above and construct the concept of radio

communication. Your answer should be based on the following steps:

Identify the information [1 mark]

Identify the common characteristics [2 marks]

Relate the common characteristics to the radio communication in order

to construct the initial concept.

[1 mark]

Give an example of another radio communication and a non radio

communication

[1 mark]

State the actual concept of radio communication [1 mark]ANSWER:

20(a) - It can travel through vacuum

- It moves with the speed of light, so it can transmit the information very fast.

- It acts as a carrier wave for audio and video signals

- It is not easy to be spread through an obstruction

(b)

Identify the information Local radio broadcast use the long wave with low

frequency of the radio wave as a carrier wave to deliversound information

Identify the commoncharacteristics

- Radio broadcasts across continent use short waves withhigh frequency of the radio wave as a carrier wave to

deliver sound information- TV Astro broadcasts use microwaves with the highest

frequency of radio wave as a carrier wave to deliver sound

and picture information

Relate the commoncharacteristics to the

radio communication in

order to construct the

All the three radio communications above use the wave ofdifferent frequency of radio waves in electromagnetic

spectrum as the carrier wave to deliver information.


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initial concept.

An example

Non example

Hand phone / FM radio broadcast

Microwave oven

Actual concept of radio

communication

Radio communication is using a range of radio waves in

the electromagnetic spectrum as carrier to deliverinformation

21 (a) State four advantages of satellite communication system to other communication system.

[4 marks]

(b) Football World Cup 2006 was held in Germany. A remote country could not get the live

television broadcasts for the tournament. Explain how the country can solve the problemso that they can watch the matches live in the next tournament.

Your answer should include the following:

Clarification of the problem [1 mark] Name the system of communication [1 mark]

Steps for the system to function [4 marks]

ANSWER:

21(a)- transmission or receiver of satellite system is not affected by the change in weather.

- it can service a wide area including the remote area


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- it does not need many relay station as microwave can move very far

- it can deliver a lot of information quickly and efficiently

- it can transmit live broadcasts through-out the world

(b)

Clarification of the problem How to get live television broadcasts?

System of communication Use satellite communication system

Steps of the system to function An earth satellite station is built in the country.Television camera will record the match in the stadium

where and when the tournament is on.

The electrical signal will be sent to the televisionstation and be transmitted by micro wave by the earth

satellite station of the host country to the

communication satellite in space.

The communication satellite in space will strengthenand transmit back to the earth's satellite station in the

remote country, and then to the local television station.

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Ramalan Esei 2011