Light — Science STD 7 — Question

On last Monday, Pankaj was dealing with immense cough and cold. Besides this, he was suffering from a headache. So, he decided to take a leave on that day so that he could take some rest at his home. After one hour he thought to check his fever through a clinical thermometer, so before using it, he washed it and started shaking it very fastly in his hand, so that the mercury level of thermometer gets reduced. At the same time, his elder brother Vishwas scold him and suggested him to shake the thermometer slowly.
(i) State some precautionary measures while checking the fever through a clinical thermometer.
(ii) Mention the values showed by the elder brother of Pankaj (i.e. Vishwas).

“Forests are our lifeline.” Write five sentences on this topic.

A fish dies when taken out of water, whereas a wall lizard will die if kept under water. Mention the term used to describe such abilities that allow fish and lizard to survive in their respective habitats.

Students of class 7th went on school trip to forest. There they observed a pond covered with a green film on surface. What can be these organisms covering the pond? Does these organisms harm the living bodies inside the pond?

While learning to ride a bicycle Boojho lost his balance and fell. He got bruises on his knees and it started bleeding. However, the bleeding stopped after some time.

1. Why did the bleeding stop?
2. What would be the colour of the wounded area and why?
3. Which type of blood cells are responsible for clotting of blood?

Explain how the digestion of cellulose occurs in grass eating animals.

Name the process and the organ which help in removing the following wastes from the body.
(i) Carbon dioxide
(ii) Undigested food
(iii) Urine
(iv) Sweat

Fill in the blanks of the paragraph given below with the words provided in the box. chlorophyll, energy, food, carbon dioxide, water, photosynthesis Note: A word can be used more than once. Leaves have a green pigment called (a) which captures (b) from sunlight. This (c) is used in the process of (d) and along with other raw materials like (e) and (f) synthesize (g).

What is symbiosis? Explain with an example.