Reproduction in Plants — Science STD 7 — Question

You must be familiar with the following nursery rhymes:

1. ‘Baa baa black sheep, have you any wool.’
2. ‘Mary had a little lamb, whose fleece was white as snow.’

Answer the following:

1. Which parts of the black sheep have wool?
2. What is meant by the white fleece of the lamb?

A steel spoon becomes hot in a bowl of soup. Why?

Differentiate between xylem and phloem.

Veins have valves which allow blood to flow only in one direction. Arteries do not have valves. Yet the blood flows in one direction only. Can you explain why?

A flat in Mumbai with a balcony facing the sea has some clothes hung on a clothes line in the balcony. Towards which direction the clothes will be blown in the afternoon? Explain.

How is the rainbow formed?

Three statements are provided here which define the terms, i.e. sludge, sewage and wastewater. Pick out the correct definition for each of these terms.
(i) The settled solids that are removed in wastewater treatment with a scraper.
(ii) Water from kitchen used for washing dishes.
(iii) Wastewater released from homes, industries, hospitals and other public buildings.

A potato slice shows the presence of starch with iodine solution. Where does the starch in potatoes come from? Where is the food synthesised in the plant, and how does it reach the potato?

Do you think an electromagnet can be used for separating plastic bags from a garbage heap? Explain.