PART - 2 CH - 8 Heredity — Science STD 10 — Question

Dharmendra is a welder, working at Amit's house. After electric welding done with naked eyes, he used a grinder to smoothen the welding joints. Accidentally, some particle fell into his eye. He was then crying due to pain. Amit took him to an eye hospital by a taxi. The doctor used a device connected to two electric wires to remove the particle from his eye. Dharmendra inquired what happened to his eye and what device did the doctor use to remove the particle from his eye. Amit as a science student of class X explained to Dharmendra and advised him to be careful in future as he had a responsible risky job of welding.
(1) Which particle fell into Dharmendra's eye while welding? What precautions should Dharmendra take while doing electric welding and grinding work?
(2) What device was used by the doctor to remove the particle?
(3) What values do you learn from Amit during this episode?

Explain why fragmentation as reproductive method can work for few but not all multi-cellular organisms.

Define the following terms:
(1) Mineral, (2) Ore, (3) Gangue.

What is meant by displacement reaction? Give examples.

Give the scientific reason : The use of dung as raw material for biogas production is profitable than using it only as fertiliser or fuel.

Your neighbour is a chain-smoker. He often suffers from cough and lung infection. His relatives often tell him to leave smoking.
(1) How inhaled air is filtered in the upper part of respiratory tract ?
(2) Which is the effect of smoking on the upper part of respiratory tract?
(3) Why do you call smoking as injurious to health?

What are Aerobic and Anaerobic respiration ? Explain the process. 

How does the design of the body solve a problem when immediate response is needed? Where should such connection be made?

Define electric current. Explain the difference between electron current and conventional current.