PART - 2 CH - 7 How do Organisms Reproduce ? — Science STD 10 — Question

Write short note on: Tissue culture###How callus is developed and what is the use of callus? Explain.

One-half of a convex lens is covered with a black paper. Will this lens produce a complete image of the object? Verify your answer experimentally. Explain your observations.

What is the role of hydrochloric acid (HCI) in digestion of food?###What are the functions of the acid in our stomach?

Give scientific reason:
Lymph separates from the blood and remixes with the blood.

Vishva noticed in a dhaba around 50 bulbs, each of 100 W all were glowing. She calculated the cost of electricity consumed in one hour and told the dhaba owner to reduce the expenses and at the same time save electricity by using CFL bulbs instead of ordinary filament-type bulbs.
(1) What would be the cost of electric energy if 50 bulbs, each of 100 W , are used for one hour? 1 unit costs ₹ 5 .
(2) What is a CFL?
(3) What value did Vishva display in the above case?

What is a neutralisation reaction? Give two examples.

When is it said that an image has been formed of an object? Clarify about the types of image.

Give scientific reason:
Candle burns with a yellow flame.

Write a short note on bleaching powder.###Explain the preparation of bleaching powder with chemical equation and also write its uses.

What is used for whitewashing of the walls of the house carried out? Explain the preparation by showing chemical equation.