*PRACTICE TEST* *PART-B*
SUBJECTIVE QUESTIONS
1. What do we call the clear water obtained by the method of filtration? (1)
2. Which is the largest source of water on the earth? (1)
3. Which gas is given to the patients having breathing problems? (1)
4. Name the structure present in red worms which helps them in grinding the food which they eat. (1)
5. What is the importance of water cycle in nature? (2)
6. Why do deep sea divers carry oxygen cylinders with them? (2)
7. What is mean by biodegradable garbage and non biodegradable garbage? (2)
Answers
Answer:
1)Ans:- A mixture of sand and water can also be separated by filtration. When the mixture of sand and water is poured on a filter paper fixed in funnel , then clear water passes through filter paper and collect as filtrate.
2)Ans:- The oceans are, by far, the largest reservoir of water on earth.Over 96% of all of Earth's water exists in the oceans.
3)Ans:- Oxygen gas is given to the patients having breathing problems.
4)Ans:- Gizzard helps Red worms in grinding their food.
5)Ans:- The water cycle is an extremely important process because it enables the availability of water for all living organisms and regulates weather patterns on our planet. If water didn't naturally recycle itself, we would run out of clean water, which is essential to life.
6)Ans:- Sea divers carry oxygen gas cylinders along with them because there is no free oxygen in the sea water since the little dissolved oxygen present in water can't be used for breathing by divers. It can be used only by aquatic animals
7)Ans:- Such substances which can be easily broken down by the action of bacteria are named as biodegradable substances. Other substances or material like plastics, metallic cans and pesticides which cannot be broken down easily by biological processes are named as non-biodegradable substances.