how do organisms reproduce ? — Science STD 10 — Question

State the charecteristics of animal hormons. State the hormons relate to grow in human being.

Ramesh's father is a farmer and he is disappointed as he cannot grow any crop on his farmland, because the land has become highly basic in nature. It happens due to paper industry nearby dumping its waste water into canals; that supply water to the farmland.
Ramesh and other youth in the village told the owner of the paper industry about the pollution caused by the paper industry.
(1) What type of land is suitable for the growth of crops?
(2) Use of fertilizers also causes change in the pH of soil. How do farmers overcome this problem?
(3) What values of Ramesh are reflected in the above case?

How do transfer of germ cells occur between two individuals for sexual reproduction?

Name and state the rule which determine the direction of magnetic field around a straight current-carrying conductor. Also draw diagram.

Why a proper system of transportation is essential in plants?

Write the definition of displacement reaction. Give one example of it and explain, how is it different from double displacement reaction.

What is redox reaction ? Explain with examples. 

A mixture of oxygen and ethyne is burnt for welding. Can you tell why a mixture of ethyne and air is not used?

What are Electrolytic decomposition and photolytic. 

Rakesh visited the government hospital to meet his cousin. He observed the medicine in dark bottles were not stored properly. They were not kept away from light and heat. Rakesh immediately reported the same to the medical superintendent and made sure that all medicines are stored properly.
(1) Why are some medicines stored at cool places in dark bottles?
(2) Why do some medicines are kept in refrigerator ?
(3) What value of Rakesh is seen in this act?