Questions

Fermentation is the chemical breakdown of a substance by bacteria, yeasts, or other microorganisms, typically involving effervescence and the giving off of heat.

The two most common types of fermentation are

(1) alcoholic fermentation (and) 

(2) lactic acid fermentation.

(1) Alcoholic fermentation : the type of fermentation in which ethyl alcohol is the main end product .This is very common in yeast (unicellular fungus) and also seen in some bacteria. Yeast cells release enzymes called zymase complex which bring about the fermentation. The reactions are similar to anaerobic respiration.

(2) Lactic acid fermentation : The type of fermentation in which lactic acid is the end product.

It is carried out by some bacteria (e.g. lactic acid bacteria), and also by animals (muscle glycolysis in animals, under oxygen deficiency, results in the formation of lactic acid this is whay we experience in muscle cramps, or "Charley horse").

DNA is not a single stranded and does not have amino acids. Hence options, b & C are eiminated. Dna is a double helix structure containing nucleobase—either cytosine (C), guanine (G), adenine (A), or thymine (T)—as well as a monosaccharide sugar called deoxyribose and a phosphate group. 

The nutrient which provides the maximum energy is Fat. It provides the energy of 9 calories/gram.

A tenant farmer is one who resides on land owned by a landlord. These farmers would have to share the yield with the landowner in a process known as sharecropping. In the South, these farmers need to have their own tools and animals.