paper 3 (biology) writing time: 1 total marks : 80...

BCSE/Bio/2014 of 24

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This booklet contains 24 pages.

Alternative No: Index No:

Supervising Examiner's/Invigilator's initial:

Paper 3 (Biology) Writing Time: 12

1 Hours

Total Marks : 80

READ THE FOLLOWING DIRECTIONS CAREFULLY:

1. Do not write for the first fifteen minutes. This time is to be spent reading the questions. After having read the

questions, you will be given one and a half hours to answer all questions.

2. Write your index number in the space provided on the top right hand corner of this cover page only.

3. In this paper, there are two sections: A and B. Section A is compulsory. You are expected to attempt any four

questions from Section B.

4. The intended marks for questions or parts of questions, are given in brackets [ ].

5. Read the directions to each question carefully and write all your answers in the space provided in the

question booklet itself.

6. Remember to write quickly but neatly.

7. Do not remove or tear off any page from the question booklet.

8. Do not draw lines or pictures on or in the question booklet to beautify it.

9. Do not leave the examination hall before you have made sure that you have answered all the questions.

For Chief Marker’s and Markers' Use Only

Question

Number

Total Chief

Marker’s

Signature

↓↓↓↓

Award

Markers’

initial →

0 1 0

1 4

1a 1b 1c 1d 1e 1f 2 3 5 4 6 7 1g

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SECTION A (40 Marks)

Compulsory: Attempt all questions.

Question 1

(a) Directions: Each question in this part is followed by four possible choices of answers.

Choose the correct answer and write it in the space provided. [15]

(i) In case of bleeding from a cut in the skin, the following are the First Aid Steps

to be followed EXCEPT

A apply disinfectant.

B wash the cut surface.

C raise the affected part.

D press the area with a clean cloth.

Answer:…………………………………………………………………………………….

(ii) What is the possibility of getting a colour blind daughter from a carrier mother (XXº)

and colour blind father (XºY)? [Colour blind trait is recessive]

A 25%

B 50%

C 75%

D 100%

Answer:…………………………………………………………………………………….

(iii) Transpiration will be faster when the

A humidity is high.

B velocity of wind is high.

C concentration of CO2 is high.

D atmospheric pressure is high.

Answer:…………………………………………………………………………………….

(iv) The safest contraceptive method is

A intra-uterine device.

B sperm killing agent.

C surgical method.

D condom.

Answer:…………………………………………………………………………………….

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(v) The fluid between the amnion and embryo which protects the foetus from physical

damage is

A synovial fluid.

B lacrimal fluid.

C amniotic fluid.

D cerebrospinal fluid.

Answer:…………………………………………………………………………………….

(vi) If the placenta of a human female is permeable to any substances, then the

A offspring will be born with disorders possessed by the mother.

B delivery of the offspring can be complicated.

C offspring will be born without disorders.

D offspring born will die soon.

Answer:…………………………………………………………………………………….

(vii) One of the advantages of local defence system over the immune system is that they

A are specific in action.

B are natural defence system.

C can prevent all kinds of infectious agents.

D can prevent wide range of infectious agents.

Answer:…………………………………………………………………………………….

(viii) What would happen to a cell, if its plasma membrane is permeable?

A The cell would be shapeless.

B The cell would function normally.

C The cell would maintain its shape.

D The function of the cell would be disturbed.

Answer:…………………………………………………………………………………….

(ix) The middle piece of a sperm cell provides

A gene.

B food.

C energy.

D chromosomes.

Answer:…………………………………………………………………………………….

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(x) On a sunny day, leaves of a maize plant wilt because

A of excessive loss of water through transpiration.

B photosynthesis is taking place.

C guttation is taking place.

D heat burns the leaves.

Answer:…………………………………………………………………………………….

(xi) What would be the phenotypic ratio of a monohybrid cross for a heterozygous

round pea seed (Rr)?

A 3 : 1.

B 1 : 1.

C 100% pure round.

D 100% pure wrinkled.

Answer:…………………………………………………………………………………….

(xii) Kinley walks clumsily after taking alcohol because it has affected his

A medulla oblongata.

B hypothalamus.

C cerebellum.

D cerebrum.

Answer:…………………………………………………………………………………….

(xiii) Growth rate is the

A number of live births per 1000 of population per year.

B number of deaths per 1000 population per year.

C total population plus the number of birth per year.

D difference between birth rate and death rate.

Answer:…………………………………………………………………………………….

(xiv) The correct sequence of the flow of an impulse in a reflex arc is

A stimulus → effector → CNS → receptor → response.

B stimulus → receptor → CNS → effector → response.

C response → receptor → CNS → effector → stimulus.

D response → effector → CNS → receptor → stimulus.

Answer:…………………………………………………………………………………….

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(xv) In a male, testes hang down away from the body when it is too hot

A because there is excess production of sperm.

B because testes expand due to heat.

C to escape body heat.

D to absorb heat.

Answer:…………………………………………………………………………………….

(b) Name the following with appropriate term/s: [5]

(i) A thin sheet of fibres which connects the two cerebral hemispheres.

………………………………………………………………………………………………

(ii) The fixation of an embryo on the wall of the uterus.

………………………………………………………………………………………………

(iii) The structural and functional unit of life.

………………………………………………………………………………………………

(iv) A process which helps the plant in the distribution of water and minerals.

………………………………………………………………………………………………

(v) The specific DNA sequence of a chromosome which controls the

expression of characteristics.

………………………………………………………………………………………………

(c) I. Write TRUE or FALSE for the following statements: [3]

(i) The absorption of water by a dry bean seed when soaked in water is an

example of imbibition.

………………………………………………………………………………………………

(ii) Hormones are secreted from their source directly into the lymph.

………………………………………………………………………………………………

(iii) A cell will swell-up when placed in a hypertonic solution.

………………………………………………………………………………………………

(iv) Pema ran when he saw a giant snake. This ability is due to the release

of adrenalin.

………………………………………………………………………………………………

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(v) The O2 released during photosynthesis is from CO2.

………………………………………………………………………………………………

(vi) Light dependent phase of photosynthesis takes place in thylakoids.

………………………………………………………………………………………………

II. Rewrite the false statements in the correct form by changing only

the underlined words. [3]

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

(d) Choose the correct alternatives from those given in brackets for the following

statements: [5]

(i) The process involved in the addition of salt in a pickle to stop the growth of

microorganisms is ………………………..

( plasmolysis / deplasmolysis / diffusion )

(ii) Mule is a cross between a horse and a donkey. If the horse has 64 chromosomes

and the donkey has 62 chromosomes, the number of chromosomes in the mule

would be ……………………….. (62 / 63 / 64).

(iii) Immunity produced by one’s own body is ………………………..

(active immunity / passive immunity / innate immunity)

(iv) The international organization concerned with collecting and supplying

information about the occurrence of epidemic diseases is ……………………

(UNO / Red Cross / WHO)

(v) Sonam was able to adjust his vision in the bright light after coming out of a

dark room. This is due to the regeneration of ………………………..

(iodopsin / rhodopsin / visual pigments)

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(e) Match the item of Column A with the most appropriate item of Column B.

Rewrite the correct pairs in the spaces provided. [5]

Column A Column B

i) DNA

ii) Cerebrum

iii) Simple goitre

iv) Antiseptic

v) First Aid

a) lysol

b) Red Cross

c) vision

d) genetic constitution

e) hypothyroidism

f) phenol

g) WHO

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

(f) A population growth curve of a country X is given below. Study the graph and

answer the questions that follow:

(i) What does the graph show about the population growth of country X? [½]

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

Po

pu

lati

on

Time

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List any three causes for such type of population growth. [1½]

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

(g) (i) Observe the diagram given below and redraw a sketch of the opposite state in

the space provided. [1]

(ii) The diagram below shows a certain phenomenon. Where does this phenomenon

occur in a plant? [1]

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

water

sugar solution

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SECTION B (40 Marks)

Attempt any four questions.

Question 2

(a) The diagram given below shows an animal cell. Study the diagram and answer the

questions that follow:

(i) Label the parts numbered 1, 2, 3 and 4. [2]

1……………………………………………………………………………………………

2……………………………………………………………………………………………

3……………………………………………………………………………………………

4……………………………………………………………………………………………

(ii) Give one function of the part numbered 2. [1]

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

1

2

3

4

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(b) Write down any two differences between the following pairs in the table given below: [4]

(i)

Transpiration Guttation

(ii)

Natural reflex Conditioned reflex

(c) Give the appropriate terms for the following statements: [3]

(i) A type of cell division leading the growth and development.

………………………………………………………………………………………………

………………………………………………………………………………………………

(ii) The pressure exerted by the cell content on the cell wall.

………………………………………………………………………………………………

………………………………………………………………………………………………

(iii) The place of best vision of the normal eye.

………………………………………………………………………………………………

………………………………………………………………………………………………

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Question 3

(a) Black fur in rabbit is dominant over white fur. If a heterozygous male rabbit is

crossed with heterozygous female rabbit,

(i) Construct a pedigree chart to show the possible phenotype of offspring. [2]

(ii) Write the genotypic ratio from the above pedigree chart. [1]

(iii) Is the fur colour sex-linked trait? [1]

………………………………………………………………………………………………

………………………………………………………………………………………………

(b) Explain briefly.

(i) Sex of a child is determined by the father’s sperm. [2]

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

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(ii) A fresh water fish does not survive when placed in sea water. [2]

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

(iii) Both the fallopian tubes in a female should be blocked to avoid pregnancy. [2]

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

Question 4

(a) Given below is a diagram showing a defect of the human eye. Study the diagram

and answer the questions that follow:

(i) Identify the defect. [1]

………………………………………………………………………………………………

………………………………………………………………………………………………

A

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(ii) Draw a diagram to show how the above mentioned defect can be corrected. [2]

(iii) Name the watery fluid which fills the part of the eye marked A in the diagram

given above. [1]

………………………………………………………………………………………………

(b) Complete the following table by filling in the blanks numbered 1, 2, 3 and 4. [2]

Source Hormone Function

Posterior pituitary

1…………………………

Stimulates milk secretion

2…………………….......

Insulin

Lowers blood sugar level

Thyroid

3…………………………

Promotes tissue metabolism,

growth and differentiation

Adrenal cortex

Sex corticoids

4…………………………….......

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(c) Answer the following questions:

(i) Describe how skin and hair in the human body acts as a local defence system. [2]

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

(iii) In some culture, couples prefer to have a male child which has led to a rapid

population growth. Discuss if this could be one of the causes of population

growth in Bhutan too. [2]

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

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………………………………………………………………………………………………

Question 5

(a) Given below is an experimental set-up of photosynthesis. Study the diagram and

answer the questions that follow:

(i) What conclusion can you draw from the above experiment? [1]

SUNLIGHT

Gas

Pond water

Hydrilla

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………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

(ii) What would happen, if the plant used in the above experiment is replaced by a

pea plant? [1]

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

(iii) Explain briefly how the process in the above experiment benefits human beings. [1]

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

(iv) Design a CONTROL set-up for the above experiment. [2]

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(b) Answer the following questions:

(i) Write down one advantage of educated parents in controlling population

growth. [1]

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

(ii) How does root pressure help the plant? [1]

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

(iii) Explain the significance of crossing-over during Meiosis. [1]

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

(iv) Pituitary gland is considered as the Master of all glands. Explain. [1]

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

(iv) ‘Vaccination is not a method of cure against a disease’. Justify the statement. [1]

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

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Question 6

(a) Give reasons for the following statements:

(i) A pregnant women should eat nutritious food. [2]

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

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(ii) It is not advisable to move fractured bones of a patient after an accident. [2]

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

(b) Write short notes on the following:

(i) The roles and responsibilities of Local Health Organisation [2]

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

(ii) Diabetes [2]

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

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………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

(iii) Vasectomy [2]

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

Question 7

(a) Given below is the internal structure of a human ear. Study the diagram carefully

and looking at the example given below, complete (i) and (ii). [1]

Example: Setting sound waves into vibration: 1

(i) Transmit the impulse to the brain: ………………………………………..

(ii) Body balance when in motion: ……………………………………………

(b) (i) How does the method of Tubectomy contribute in controlling population?

Explain briefly. [1]

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

1 2 3

4

5

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………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

(ii) Write any two differences between antiseptic and disinfectant in the table

given below. [2]

Antiseptic Disinfectant

(iii) ‘Huge roots, thin walls of root hair and low concentration in the root hair

allows absorption of water by plants’. Rewrite the statement in the correct

form by changing the underlines words. [1]

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

(iv) ‘Drops of water along the margin of the leave of certain plants is not due to

transpiration’. Support the statement. [1]

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

(v) What would happen, if both the ovaries released a mature egg every month? [2]

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

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(vi) With the help of a diagram, design a simple experimental set-up to

demonstrate that only roots absorb water. [2]

paper 3 (biology) writing time: 1 total marks : 80...

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