Secondary School (English Medium) (5 to 8) कक्षा ८ - CBSE Question Bank Solutions for Science

Given below is a conversation between two farmers Heera and Beera.

Heera : Brother Beera, your maize crops look beautiful. They have grown pretty fast.

Beera : Yes, I have sprayed urea this time. What about you?

Heera : Well, I am still relying on good old cow dung. I am saving money for buying a tractor.

Beera : That’s good. Tractor saves a lot of time and labour.

Heera : Yes, it’s been very labour intensive for me and now these weeds have come up.

Beera : Try weedicides, they are very effective.

Now, answer the following questions.

1. List the practices which are not environment friendly and why?
2. What is the advantage of modern agriculture implements over traditional ones?
3. Name one weedicide and the precaution, farmers must take during its application. 

Despite being one of the growing economies, our country still has a large section of population going hungry and malnourished. Do you think an efficient crop production mechanism is the only solution to this? Discuss in the class what else needs to be done to root out hunger and malnutrition from our country.

Which of the following feature will help you in distinguishing a plant cell from an animal cell?

What are the functions of cell wall in plant cells? 

Observe the following figure given below.

Answer the following questions.

1. Does it represent a plant cell or an animal cell?
2. Does it represent a prokaryotic cell or an eukaryotic cell?

Label the parts A to E in the given figure.

It is much easier to burst an inflated balloon with a needle than by a finger. Explain.

1 hertz is equal to

Ultrasound has frequency of vibration

Unwanted or unpleasant sound is termed as music.

Unwanted sound is called ______.

What is the difference between noise and music?

Name the practice followed for large scale rearing of farm animals.

What facilities are provided to farm animals?

Noise pollution may cause partial hearing impairment.

List sources of noise pollution in your surroundings.

Explain in what way noise pollution is harmful to humans.

Your parents are going to buy a house. They have been offered one on the roadside and another three lanes away from the roadside. Which house would you suggest your parents should buy? Explain your answer.

Boojho saw a cracker burst at night at a distance from his house. He heard the sound of the cracker a little later after seeing the cracker burst. Give reason for the delay in hearing the sound.

List three sources of noise pollution in your locality.