Nutrition in Animals — Science STD 7 — Question

Various steps involved to obtain wool from fleece are given here.

1. Picking out the burrs.
2. Dyeing in various colours.
3. Shearing.
4. Scouring.
5. Sorting.

Write the above steps in the correct sequence in which they are carried out.

Sachin lives in a village, this village is surrounded by a forest. One day he noticed that in nearby pond sedimentation is increased so much that water has become muddy, streams are drying up. There is scarcity of fuel wood. He soon realised that he has to raise the issue of forest protection from cutting down trees, etc. Soon he gathered the nearby village people and made an organisation to take an initiative.
Now, answer the following questions
(i) What changes might have Sachin noticed in his area?
(ii) Give the probable reason for such changes mentioned above.

Explain the process of weathering of rocks and how it involves both physical and chemical changes.

An adolescent often reacts strongly to minor disagreements, sometimes withdrawing and at other times lashing out. His/her relationships with friends and family are becoming strained. What might be contributing to such behaviour, and how can adolescents develop healthy responses to emotional changes?

When baking soda is mixed with lemon juice, bubbles are formed with the evolution of a gas. What type of change is it? Explain

Observe the formation of shadows by a glass plate, an wooden piece and a tracing paper and record your result.

Explain briefly how the uneven heating between the equator and the poles generate wind currents.

Which gas present in air is essential for aerobic respiration? What is the role of oxygen during respiration?

We can see objects when the lighted reflected from the objects falls upon our eyes. Why can't walls act as mirror even the light is reflected through walls and reach our eyes?

How do plants transport raw materials to the food factories of the plants?