Answer: Option C. -> Saliva is secreted by six pairs of salivary glands in human beings
:
C
There are three pairs of salivary glands in man which secrete saliva into the oral cavity through ducts. About 1000-1500 ml of saliva is secreted per day.

Answer: Option C. -> Wisdom teeth
:
C
Vestigial organs are present in reduced form and they are of no use to the animal, in which they are present. Man has 180 vestigial organs, eg, nictiating membrane, vermiform appendix, wisdom tooth, muscle of pinna and forehead, mammary glands in male.

Answer: Option A. -> Digestion
:
A
Glucose is amicro molecule and needs no digestion. It is also the primary source of energy for the body. Glucose is absorbed by the cells and burned during cellular respiration to generate energy.

Answer: Option A. -> Pancreas
:
A
The ‘islets of Langerhans’ are the clusters of cells of the endocrine portion of pancreas. They produce hormones Insulin, Glucagon and Somatostatin

Answer: Option A. -> Liver
:
A
Kupffer cells, also known as stellate macrophages are specialized macrophages located in the liver, lining the walls of the sinusoids that form part of the mononuclear phagocyte system.

Answer: Option B. -> Protein digestion begins in the stomach
:
B
Dietary proteins are first denatured by the hydrochloric acid secreted by the parietal cells of gastric glands (the weak non-covalent interactions that hold proteins in their specific 3-D configuration are disrupted exposing many peptide bonds that were initially shielded inside the protein). The cells of the stomach epithelium secrete pepsinogen (stimulated by the hormone gastrin) which is activated to pepsin initially by the hydrochloric acid, then by autocatalysis by pepsin itself. Pepsin then begins the specific partial hydrolysis of the denatured proteins in the stomach where the pH of the environment is 1-2 (optimum pH of pepsin). Pepsin is an endopeptidase that only hydrolyses those peptide bonds in which an aromatic amino acid supplies the NH of the peptide bond.
Trypsin is synthesised in the pancreas as trypsinogen (together with other proenzymes) and released into the small intestine. It is not present in the stomach.

Answer: Option C. -> Cellulase
:
C
Human digestive juices lack cellulase which digests cellulose. Cellulose thus acts as dietary fibers that help is the easy egestion of the food from the large intestine.

Answer: Option A. -> Carbohydrate-fat-protein
:
A
During starvation, that is when food requirement of body is not fulfilled by the ingested food, reserve carbohydrate is used first by the body and after carbohydrates, fat is used as energy and at last when carbohydrates and fats are consumed, proteins are used as a source of energy. Proteins are usedat last because proteins are the main structural component of the body and the net energy produced by burning protein is less.

Answer: Option B. -> Enteropeptidase
:
B
The inactive precursor of trypsin, produced by the pancreas and converted to trypsin in the small intestine by enteropeptidase.

Answer: Option A. -> Fats
:
A
The calorific value of food is the amount of energy released by the complete oxidation of food. One g of fat yields 9.3 kcal (1 kcal = 4.1868 × 1000 joules); 1 g of carbohydrate yields 4.1 kcal; and 1 g of protein yields 4.1 kcal.