Questions

A cell undergo meiosis, and it produces 4 haploid cells from a single diploid cell.

Hence, the given statement is true.

An autoimmune disease is a condition in which your immune system mistakenly attacks your body.

The immune system normally guards against germs like bacteria and viruses. When it senses these foreign invaders, it sends out an army of fighter cells to attack them. Normally, the immune system can tell the difference between foreign cells and your own cells.

In an autoimmune disease, the immune system mistakes part of your body — like your joints or skin — as foreign. It releases proteins called autoantibodies that attack healthy cells. Some autoimmune diseases target only one organ. Type 1 diabetes damages the pancreas. Other diseases, like lupus, affect the whole body.

Hence, Systematic lupus erythematosus is an autoimmune disease that affects multiple organs.

Secondhand smoke is very dangerous and creates serious health risks to you and your family members. 

Vitamin B12 is the only water-soluble vitamin that can be stored in the liver for many years. There are 9 water soluble vitamins.

True, the greenhouse effect is caused solely by human activities such as deforrestation, depletion of natural resources and emission of CO2 by using vehicles, refrigerators and AC's.