Respiration in Organisms — Science STD 7 — Question

Harish went to visit his grandfather in village where he saw that his grandfather’s field of wheat are infected with fungus but no one is aware of this. Harish rushed to his grandfather’s side and told him that the field have been infected with fungi. He should use an antifungal agent in his fields to stop this infection.

1. What is fungus?
2. Can fungus only cause diseases or can it be helpful also?
3. What values are shown by Harish?

Fill in the blanks in the following statements using words given in the box.

air, handpumps, cholera, water, large, ground.

A very _______ number of our people defecate in the open. It may cause _______ pollution and soil pollution. Both the surface water and _______ water get polluted. _______ water is the source for wells, tubewells and _______. Thus it becomes the most common route for _______ borne diseases like _______, dysentery, etc.

Ravi was sitting in a garden with his family. His younger sister came running with different types of flowers and started to name their parts. She stoped as she forgot some names and Ravi noticing this, came to help her.
His sister asked many questions related to flowers and Ravi answered her with all information he had.
(i) What is a flower? Mention its function during reproduction.
(ii) Flowers help in pollination and fertilisation. Yes/No. Give reason.

Write short notes on Short Circuiting.

Draw a labelled diagram to show (a) open circuit (b) closed circuit and explain.

Distinguish between the following. Real image and Virtual image.

Differentiate between two modes of transfer of heat, i.e. convection and conduction.

Rahul was a student of class VII. His father purchased a new bicycle for him on his birthday. After few months, he found that the cycle chain and the handle gets rusted. His father advised him to apply a coating of paint to the cycle and not to keep it in the open in future.
Now, answer the following questions
(i) Why his cycle gets rusted?
(ii) What do you mean by rusting of iron?

Explain the difference between xylem and phloem.

State similarities between the laboratory thermometer and the clinical thermometer.