Q.4.A. Give reasons for the following (any 3).
1 Whales and dolphins often come up to the water surface
2. Forest prevent soil erosion
3. A coil of nichrome wire is used in an electric iron
4. Xylem and phloem are called vascular tissue
5. Blood is important circulating fluid of body
Answers
Answer:
1) Answer- Whales and dolphins use their lungs to breathe air also. That's one reasons why they come to the surface of the ocean.
2) Answer- Forests are rich in vegetation. Herbs, shrubs and trees in the forests hold the top most layer firmly by their roots. This does not allow natural forces like wind and water to carry away the top most fertile layer of the soil easily. Hence, forests prevent soil erosion
3) Answer- High resistivity thus ensuring the wires to heat up faster. High specific heat which provide enough heat to the element.
4) Answer- It consists of many elements which all together form a tubular chain like structure that connects the root to the stem and the leaves of the plant. ... Thus, xylem and phloem are called the conducting or vascular tissues in plants
5) Answer- Blood is a constantly circulating fluid providing the body with nutrition, oxygen, and waste removal. Blood is mostly liquid, with numerous cells and proteins suspended in it, making blood "thicker" than pure water.
Hope it helps you!!