Nunamas Highlighted Sc.docx

NUNAMAS- Highlighted Questions Set 1 1.

Special structure at trachea: Ring of cartilage: Support and prevent trachea from collapsing. 2. Parts of gas turbine generator:

3. Why the skeleton of the aquatic vertebrate is smaller compared to land vertebrates even though it has enormous size?  Supported by water buoyancy  Bone supports parts of the body weight- so the body size can become huge. 4. Explain how tendrils respond to stimulus  The tendrils respond to the touch and contact stimulus.  The tendrils curl around an object that touches them. Extra: Cucumber  Place wooden stick upright position between the stems of the cucumber plant.  The tendrils of the plant will twin round the wooden stick to keep the plant in upright position.  This response in known as thigmotropism. 5. Difference between endoskeleton and exoskeleton:  Endoskeleton is the support structure inside the body whereas exoskeleton is the hard outer protective structure such as shells. 6. Application of expansion and contraction of matter.  Thermometer  Fire alarm  Thermostat

©Eric K. Sept. 2017

7. Moment of force:  The rotation effect when the force is exerted to an object thus causing the object to rotate at a fix point called the pivot/ fulcrum. (Nunamas)  When a force is applied on an object, the force will turn the object about the pivot or fulcrum. (Sasbadi SPS)  The turning effect in applying a degree of force. (Oxford Fajar Success)  It is defined as the product of the force (F) and the moment arm (d). The moment arm or lever arm is the perpendicular distance between the line of action of the force and the centre of moments. Moment = Force x Distance or M = (F)(d) The Centre of Moments may be the actual point about which the force causes rotation. (Google)  Moment of force (often just moment) is a measure of its tendency to cause a body to rotate about a specific point or axis.(Wiki) 8. Electrostatic force  A type of force experienced by the charged objects when brought closer to each other 9. Lightning  The water molecules in the cloud experience friction with the fast moving air causes the cloud to be charged.  When the charged cloud pass through a building or another cloud with opposite charged, pulling force occurs  Lightning occurs as negative charges from the cloud moves rapidly to another cloud or to the earth which is positively charged. (Nunamas)  Clouds are charged when the water vapour in them rubs with the air particles. When a negatively-charged cloud moves closer to another cloud or to the Earth’s surface that has an opposite charge, the negative charges ‘jump’ from one charged cloud to another, or to the ground. Lightning is produced. The lightning conductors fixed on a building allow charges of lightning to flow to the Earth. (Sasbadi SPS) 10. The lightning rod  When a building with lightning rod is struck by lightning, the lightning rod will provide a pathway that allows electrons to flow into the earth without damaging the building. Extra: Oil tanker: 

A petrol tanker becomes charged with static electrical charges as it moves and rubs with the air. The rubber tyres prevent the charges from flowing to the Earth. Therefore, a metal chain is fixed to the tanker to allow the charges to flow to the Earth as the chain touches the road to prevent sparks that can cause a fire from being produced.

Aeroplane   

Aeroplane becomes charged as they fly through the air. The body of the aeroplane rubs against the hot and dry air. Carbon in the tyres of an aeroplane enables the charges to flow to the ground on landing As an additional safety measure, a strip of metal conductor is fixed to an aeroplane to enable the charges to flow to the ground when the plane is landing

©Eric K. Sept. 2017

Metal doorknobs  

When a person walks across a carpeted floor, electrons are rubbed off the carpet by his shoes. Electrons then spread over the surface of his skin. When he reaches for a metal doorknob, he may feel an electric shock. This is because the attractive electrostatic force between the electrons of his hand and the positive charges on the doorknob pulls the electrons from his hand to the doorknob.

11. Diagram below shows the growth rates of the body parts of humans.

What is the part labelled X? Explain your answer.  Reproductive organs  They only start to develop when an individual reaches puberty. 12. Diagram below shows Ali is pouring excess solution back to the Reagen bottle.

Does Ali’s action acceptable? Explain.  No, the chemical may contaminated.  It will affect the result of next experiment. 13. Suggest a method to store the chemical substances with the symbol below.

Keep in paraffin oil.

©Eric K. Sept. 2017

14. Importance of national grid networks:  Electrical energy from a power station of a region which require electrical energy  A power station can be close for repair/ maintenance without disturbing the electric supply to the household’s consumers. 15. Fractional distillation

Mistake?  Direction of the water flowing into and put of the liebig condenser is wrong  Condensation does not occur  Vaporised fraction of petroleum cannot be collected as distillate Extra: Glass wool -To break bubbles 16. Why insect suitable as good pollinator?  Hairy body stick to the pollen  Have a small body size to stay on the flower easily  Work in large number and collect honey continuously Extra: Insects and flower, why mutualism? 

A host plant receives the service of insect pollination in return for a reward provided for its insect pollinator. Typically, the reward is nectar or pollen, but occasionally the provision can be a mating site, resin for nest construction, floral aroma, or even the attraction of plant-generated heat. 17. Painting a car

©Eric K. Sept. 2017

How can the car be positively charged?  Connect to the positive voltage  Can be earthed Advantages?  The paint droplets are attracted to the body part, producing am even coat with little waste  The droplets of paint gain the same charge, so they will repel to each other and produce a dine spray 18. Modification: Insecticides Spray

19. Stability of animals: a. Sole pads of camel  The camels have broad pads.  The pads have long curve nail that help to grasp into the sand b. Elephants  Elephants have short legs to lower the centre of gravity  Large feet to increase base area 20. Modification: Save the baby elephant

©Eric K. Sept. 2017