Biology Questions

The nucleotides that are present in DNA molecule are 4. They are Thymine (T), Guanine (G), Adenine (A) and Cytosine (C).

Here in this Adenine pairs with Thymine (A - T) and Cytosine pairs with Guanine (C - G).

High frequency sound attacks the tympanic memberane and makes it defective. 120 decibles is too high a pitch to be heard and therefore it impairs the hearing ability.

Genes are located on DNA present in the chromosome. Chromosomes are present in the nucleus of the cell.

Enzymes play an essential role in each living cell of our body. Enzymes are globular proteins that control biological reactions. These are of two types.

1. Intracellular enzymes

2. Extracellular enzymes

Intracellular enzymes are found inside the cell.

Extracellular enzymes act outside the cell.

Enzymes are produced by exocrine glands.

Digestive enzymes of diverse specificities are secreted by the salivary glands, stomach, pancreas, and the small intestine.

All living cells arise from pre-existing cells is one component of the cell theory.

The Cell Theory is one of the basic principles of biology.

The Cell Theory states:

1. All living organisms are composed of cells. They may be unicellular or multicellular.

2. The cell is the basic unit of life.

3. Cells arise from pre-existing cells.

Spleen is called as the graveyard of RBC Red Blood Cells where they are selectively destroyed/recycled by macrophages.

Saliva is produced by the salivary gland which helps in food digestion.

Option A) contains fluoride to harden the tooth enamel is not the function of saliva.