SULIT855

Assessment 1 (March 2015)ScienceSecondary 21 hour

Name: Class:

1Diagram 1.1 shows the structure of the human ear.CAD

E

B

Diagram 1.1

(a)On Diagram 1.1, tick () the correct letters to show the organs that are involved in the mechanism of hearing.[3 marks]

(b)Tick () the functions of the part labelled B.Amplifies sound vibrations

Channels sound waves to the eardrum

Converts sound vibrations into nerve impulses

Transfer sound vibrations to the oval window

[2 marks]

(c)Mirah feels dizzy when she spins quickly for a few rounds as shown in Diagram 1.2.

Diagram 1.2Inside your ears are tubes filled with a liquid. The liquid moves when you move, telling your brain what position your body is in. When you spin, the liquid also spins. The liquid continues to spin after you have stopped. Your brain thinks youre still spinning, so you will feel that everything is going in circles until the liquid stops moving.

By referring to Diagram 1.1, tick () the part of the ear which is responsible for the occurrence.BDE

[1 mark]

2Diagram 2.1 shows the structure of the human eye.B

C

D

E

A

F

G

Diagram 2.1

(a)On the diagram, tick () the correct alphabets to show the parts that are involved in the human mechanism of sight.[3 marks]

(b)Tick () the correct functions of the part labelled D.(i)Protects the eye and maintains the shape of the eye.

(ii)Supply nutrients and oxygen to the eye.

(iii)Detects images of the objects formed and changes them to nerve impulses.

(iv)Absorbs light and prevents reflection of light in the eye.

[2 marks]

(c)Diagram 2.2 shows two types of vision defect, R and S that are commonly facing by humans.

Thick lens

Light rays from distant objectImage focused in front of retina

R

Thin lens

Light rays from near objectImage focused behind retina

S

Diagram 2.2

Tick () one difference between the main cause of vision defect R and vision defect S.(i)R occurs due to the eyeball that is too long whereas S occurs due to the eyeball that is too short.

(ii)R occurs due to the eyelens that is too thin whereas S occurs due to the eyeball that is too thick.

[1 mark]

(d)How can the vision defects in both R and S be corrected?R : Concave lensS : Convex lens[2 marks]

3Diagram 3 shows a section through the human skin.SRQP

Diagram 3(a)Name all the labelled receptors.P:Heat receptorQ:Pain receptorR: Cold receptorS: Touch receptor[4 marks]

(b)By making a suitable comparison, explain how the thickness of epidermis affects the sensitivity of the skin.The thinner the epidermis, the more sensitive the part of the skin is. (2m) Fingertips/necks/cheeks/palms are thinner than elbows/soles. Thus, fingertips/necks/cheeks/palms are more sensitive than elbow/soles. (2m) [4 marks]

(c)Our fingertips are known to have very high degree of sensitivity. State one benefit for such sensitivity.High degree of sensitivity on the fingertips enables the blind to read Braille [1 mark]

4Diagram 4 shows an activity carried out by a student. Glass

Plastic tube

EarAsbestos sheet

Stopwatch

Cloth

Plastic tube

Ear

Asbestos sheetStopwatch

Diagram 4

(a)State the aim of the activity.To study the reflection and absorption of sound[1 mark]

(b)State the variables involved in this activity.(i)Constant:Position the asbestos sheet/location of the ear/ Type/position/material of plastic tube(ii)Manipulated:Type of surface(iii)Responding:The loudness of the ticking sound from the stopwatch[3 marks]

(c)Write the observation for the activity in the table below.Type of surfaceObservation

GlassThe sound of the stopwatch can be heard clearly

ClothThe sound of the stopwatch cannot be heard clearly

[2 marks](d)Based on your observation, state the type of surface which is a better :(i)sound reflector:Glass / Hard and smooth(ii)sound absorber:Cloth / Soft and rough[2 marks]

(e)What is produced when sound is reflected in caves? Why?Echoes[2 marks](f)Taariq and his friends like to play different types of musical instruments especially during the weekends and holidays. However, most of the times, the neighbours would knock on his door to advise them to lower the noise. What can Taariq and his friends do to his room in order to reduce the noise?To cover the room with rough and soft surfaces that are good sound absorbers. (1m) For example, to cover the walls/windows with cloth/cork/sponge/rubber/cushion (1m) and cover the floor with carpet (1m)[3 marks]

5Diagram 5 shows the apparatus set-up to investigate the response of plants to stimuli.Petri dish

Moist cotton wool

SeedlingPlasticine

Diagram 5

(a)In the box provided in Diagram 5, draw one arrow to show the direction of growth of the roots after one week.[1 mark]

(b)Give one reason for your answer in (a).The roots grow towards gravity [1 mark]

(c)Name the type of tropism shown by the roots.Positive geotropism [1 mark]

(d)State one importance of the tropism in (c) to plants.Enables the plants to grow deeper into the soil for water and minerals. [1 mark]

(e)State two other responses of plants towards stimuli.(i)Phototropism/Hydrotropism/Thigmotropism(ii) Phototropism/Hydrotropism/Thigmotropism[2 marks]

6Read the passage below.The nose is the sensory organ that gives us the sense of smell. When we breathe, air enters through the nostrils into the nasal cavity. The roof of the nasal cavity has many sensory cells or smell receptors to detect smell. This location allows smell receptors to have the maximum exposure to air currents. The smell receptors are sensitive to all kinds of smells.The nasal cavity is also lined withMucus. Mucus warms and moisten air currentbefore it enters the lungs. Hairs in the nostriltrap dust and dirt in the air so that only clean air enters the lungs. Chemical particles, for example in food and flowers enter the nasal cavity. Chemicals dissolve in the mucus lining of the smell receptors. Smell receptors are stimulated and send out nerve impulses to the brain. The brain then identifies the smell.

(a)Based on the passage, complete the pathway for the detection of smell.

Chemicals present in inhaled air.Chemical particles enter the nostrils/nasal cavity.Chemical particles dissolve in the mucus lining.

The brain identifies the smell.Smell receptors are stimulated and send out nerve impulses to the brain.

[4 marks]

(b)Hana has flu. She doesnt have the appetite to eat because food is tasteless to her. Explain why.The nasal cavity and mouth cavity are connected. (1m) During flu, thick mucus prevent the smell receptors from being stimulated by the smell of food. (1m) [2 marks]

(c)The sense of taste and the sense of smell help us to spit out food that is spoilt or smelly before we swallow it. Explain why this is important to us.To ensure that we eat proper food (1m) and does not get food poisoning (1m) [2 marks]

END OF QUESTION PAPER

Prepared by,Checked by,Approved by,

________________________________________________(Ms Sue Soh Ya Lee)(Mr Leong Chee Fei)(Mr Rohaizi Rastam)Subject TeacherCurriculum LeaderHead of Department

55 2015 Hak Cipta Asia Pacific Smart School SULIT55 2015 Hak Cipta Asia Pacific Smart School SULIT