science

Question 1

The bat has wings to allow it to fly but it is not in the group of birds. Why?

Answer 1

Bats have the characteristics of mammals such as milk gland and give birth to youngs. Its body also covered with hair and fur.

Question 2

Compare and contrast a bat and an owl.

Answer 2

Bat gives birth while owl lays eggs.
Bat’s body is covered with fur and hair while owl’s body is covered with feathers.

Question 3

Suggest two ways to preserve and conserve the animals.

Answer 3

Implementing laws to ban illegal hunting and uncontrolled logging activities.
Setting up special protection areas for animals such as forest reserve and national parks.

Question 4

Malaysia is recognised as one of the 12 mega biodiversity countries in the world. The wet tropical climate is a factor that promotes the growth of variety of plant and animal species. Biodiversity is important to humans as well as the natural ecosystem.
Explain the importance of biodiversity in generating the country’s economy.

Answer 4

Herbs can provide us with many drugs and medicines to improve human’s health. Areas and forest that are rich in biodiversity can be developed as recreational parks to attract foreign tourists. Plant products such as rubber is used to export overseas to generate income.

Question 5

Grass is a producer. Explain how grass gets its energy.

Answer 5

Producer absorbs energy from the Sun through photosynthesis and converts into chemical energy.

Question 6

What is the importance of photosynthesis in plants?

Answer 6

Enable the plants to make its own food.

Question 7

Give two roles of living things in carbon and oxygen cycles.

Answer 7

1. Plants and animals carry out respiration by using oxygen and releasing carbon dioxide.
2. Dead living things will be decomposed by bacteria and fungi in the soil by inhaling oxygen and exhaling carbon dioxide.

Question 8

Explain what the effect of this activity is on the carbon cycle and the oxygen cycle.

Answer 8

Increasing the content of carbon dioxide in the atmosphere will cause greenhouse effect resulting in global warming up. In the other hands, the content of oxygen will decrease. This results in living organisms lack of oxygen.

Question 9

State what will happen to the stork population if there is water pollution due to the poison in the area.

Answer 9

The egret population will reduce because lots of fish died due to poisoning.

Question 10

State the example of interaction between
Living thing and living thing:
Living thing and non-living thing:

Answer 10

Living thing and living thing: The grasshopper eats the plants.
Living thing and non-living thing: Plants absorb water to carry out the photosynthesis process.

Question 11

Raju and Salim are discussing the parasitism interaction. Raju has the opinion that all worms are parasites which breed in the human intestine. For examples the tapeworm, hookworm and ringworm. However, Salim does not agree with Raju’s opinion. Give reasons why to support Salim’s opinion.

Answer 11

There are non-parasitic worms like earthworms that live in the soil. The earthworms make the soil not the compact and consequently leave oxygen in the soil for the plants’ use.

Question 12

Plants in aquariums are very important to animals because animals and plants interact with each other to ensure ecosystem balance. Do you agree with the statement? Justify your answer.

Answer 12

Yes. Plants release oxygen gas, while carrying out the photosynthesis process, which is a basic need to the fish for respiration.

Question 13

Why do the green plants play an important role in the carbon cycle?

Answer 13

The green plants maintain the content of carbon dioxide and oxygen in the air through photosynthesis process by absorbing carbon dioxide and releasing oxygen.

Question 14

Unrestricted logging has contributed to the global warming and affects the carbon cycle. How does this human activity cause global warming?

Answer 14

Unrestricted logging has increased the quantity of carbon dioxide in the atmosphere. The carbon dioxide will trap heat and increases the Earth’s temperature.

Question 15

Predict what happens if the eagles migrate into the habitat. Give your reason.

Answer 15

The number of snakes reduces because they are eaten by the eagles and owls.
The number of chameleons increases because they are not threatened by the predator.
The owls have to compete with the eagles to get the food source.

Question 16

Mr. Alaudin has an oil palm plantation. He found that the population of oil palm in his plantation was affected by the increase in the number of rats. He put an effort to overcome the problem by rearing owls as the biological control agent.

Based on the bar charts given, explain briefly the changes that occur.

Answer 16

The increase in the number of rats causes the yield of oil palm fruits to reduce because the fruits have been eaten by the rats. The presence of owls can reduce the population of rats because the rats become the food source for the owls. When the number of rats reduce, the population of oil palm fruits can be increased.

Question 17

Describe how the method gives positive impacts to Mr. Alaudin and the environment.

Answer 17

Mr. Alaudin gets more profit because the yield of oil palm trees increases. Pollution of soil and water do not occur because there is no chemical used. Only rats are targeted and other living organisms isn’t affected.

Question 18

The diagram shows the condition of paddy plants during drought season.
Explain the changes that occur to the ecosystem due to the long drought season.

Answer 18

When a long drought season happens, the population of paddy will decrease. This causes the food web in the paddy field area to be affected.

Question 19

There are two types of food digestion, which are physical digestion and chemical digestion. State one similarity and one difference between both digestions.

Answer 19

Similarity: Both digestions occur in the digestive tract.
Difference: Physical digestion does not involve enzymes, but chemical digestion involves enzymes.

Question 20

Explain briefly the importance of gastric juice secreted in the stomach.

Answer 20

Gastric juice contains hydrochloric acid that can activate protease enzyme and kills bacteria in food that enters the stomach.
Gastric juice secretes protease enzyme that breaks down proteins into polypeptides.

Question 21

A man has undergone a surgery to remove his pancreas due to the tumour problem in his pancreas. Explain the effect on the digestion process.

Answer 21

Amylase, protease and lipase enzymes cannot be produced in the small intestine to digest food. This can lead to malnutrition and vitamin deficiency.

Question 22

What is the meaning of defecation?

Answer 22

The process of elimination of faeces from the body.

Question 23

The large intestine is one of the parts in the human digestive system. What is the function of the large intestine?

Answer 23

Reabsorbs water into the body.

Question 24

State the importance of the process explained in Question 23.

Answer 24

Avoids constipation and other health problems such as colon cancer. Eliminates toxins in the body immediately.

Question 25

Explain the importance of the milk to avoid constipation.

Answer 25

The milk contains fibre. The fibre can soak up a sufficient amount of water in the bowel. It makes the faeces to pass perfectly in the large intestine and easy to be eliminated.

Question 26

Doctor: I suspect you are having constipation. You need to drink eight glasses of water a day for your health.
Mr. Jin Wei: How can I overcome this problem?

Based on the conversation, give your opinion to support the doctor’s advice.

Answer 26

Water keeps the faeces soft and easy to pass through the large intestine, and it keeps the large intestine smooth and flexible.