DIGESTION AND ABSORPTION
1. “The products of digestion like glucose and amino acids are absorbed to the blood by active transport, whereas electrolytes like chloride ions are generally absorbed by simple diffusion.” How will you differentiate active transport from simple diffusion? (Score 2)
✔️Answer:Active transport: It is the transport against the concentration gradient.Simple diffusion: It is the transport depending on concentration gradient.
2. Enzymes present in saliva, gastric juice and intestinal juice are given in the box. (Score 2)
a. Identify the enzyme present in gastric juice and intestinal juice one each.
b. Write their digestive function.
✔️Answer:(a) Gastric juice: Pepsin, Rennin, LipaseIntestinal juice: Lipase(b) Pepsin: Digests protein.Lipase: Digests lipids.
1. Observe the diagram of transverse section of human gut: (Score 2)
a. Label A, B, C and D.
b. Write any two structural modifications of mucosa at different parts of gut.
✔️Answer:(a) A= SerosaB= MuscularisC= SubmucosaD= Mucosa(b) Villi in small intestine and Rugae in stomach.
1. a) Name the following:
i. The carbohydrate splitting enzyme present in human saliva.
ii. The anti-bacterial enzyme present in human saliva.
b) In which region of the alimentary canal does the following reactions occur? (Score 2)
✔️Answer:(a) i. Salivary amylase (Ptyalin). ii. Lysozyme.(b) i. Small Intestine. ii. Stomach.
1. The following diagram shows the action of protein digesting enzymes of Pancreas. (Score 2)
a. Label the number 1, 2 and 3.
b. Endocrine part of pancreas is known as …………
✔️Answer:(a) 1. Enterokinin, 2. Chymotrypsin, 3. Dipeptides(b) Islets of Langerhans
1. Give one word for the following. (Score 2)
a. Presence of 2 sets of teeth in the life time.
b. Teeth are present in socket of Jaw bone.
✔️Answer:(a) Diphyodont(b) Thecodont
1. Name the following: (Score 2)
a. The antibacterial enzyme present in the saliva of man which helps in prevention of infection.
b. The digestive enzyme present in saliva.
✔️Answer:(a) Lysozyme(b) Salivary amylase (Ptyalin)
2. Protein digestion by proteolytic enzymes is given below. (Score 3)
a. Name the enzymes marked as A and B.
b. Identify the gland which secrete these enzymes.
c. Write the inactive form of the enzymes A and B
✔️Answer:(a) A. Chymotrypsin, B. Carboxypeptidase.(b) Pancreas.(c) A. Chymotrypsinogen, B. Procarboxypeptidase.
1. Certain indicators regarding the layers in the wall of alimentary canal are given. Name the layer against the indicator. (Score 2)
a. Formed of loose connective tissue containing nerves and blood vessels.
b. Inner most lining forms the rugae in the stomach.
c. Formed by smooth muscles.
d. Outermost layer made up of mesothelium.
✔️Answer:(a) Submucosa(b) Mucosa(c) Muscularis(d) Serosa
1. a) Observe the diagram and label A and B.
b) Dental formula of permanent teeth in man is …………… (Score 2)
✔️Answer:(a) A- Canine, B- Molars(b) ii) 2123/2123
1. From the following list, pick out the enzyme, that takes part in carbohydrate digestion. (Score 1)
(Salivary amylase, peptidase, lipase, carboxypeptidase)
✔️Answer: Salivary amylase
2. In human beings, dentition is heterodont. This condition means
a) Presence of two types of teeth
b) Presence of two sets of teeth
c) Presence of different types of teeth
d) Teeth are placed in sockets of jaw (Score ½)
✔️Answer: (c) Presence of different types of teeth
1. Construct a flowchart to demonstrate the digestion of proteins in different parts of human alimentary canal. (Hint: Any three steps only). (Score 2)
✔️Answer:(a) Transverse section of human gut.(b) A- Serosa, B- Muscularis, D- Mucosa.