NCERT Class X Science Class: Chapter –6. Life Processer – Part-11

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Question 61:

Name the energy currency in the living organisms. When and where is it produced?

Answer:

Adenosine triphosphate (ATP) produced during respiration in living organisms and also during photosynthesis in plants.

ATP (Adenosine triphosphate) is the energy currency in living organisms.

ATP is generated from ADP and phosphate ions by a complex set of processes occurring in the cell.

ATP is manufactured as a result of several cell processes including fermentation, respiration and photosynthesis. Most commonly the cells use ADP as a precursor molecule and then add a phosphorus to it. In eukaryotes this can occur either in the soluble portion of the cytoplasm (cytosol) or in special energy-producing structures called mitochondria.

Charging ADP to form ATP in the mitochondria is called chemiosmosis phosphorylation. This process occurs in specially constructed chambers located in the mitochondrion’s inner membranes.

Question 62:

What is common for Cuscuta, ticks and leeches?

Answer:

All are parasites, they derive nutrition from plants or animals without killing them.

Cuscuta, ticks, and leeches show the parasitic mode of nutrition. Cuscuta winds around plants and penetrates into the host stems via haustoria, forming direct connections to the vascular bundles of their hosts to withdraw water, carbohydrates, and other solutes. Ticks are large mites with leathery skin and in general, ticks are parasites of animals. All of them feed on vertebrate blood. Leeches are either predators (feeding on a variety of invertebrates) or blood-suckers (feeding on the blood of vertebrates).

Question 63:

Explain the role of mouth in digestion of food.

Answer:

(a) Food is crushed into small pieces by the teeth.

(b) It mixes with saliva and the enzyme amylase (found in saliva) breaks down starch into sugars.

(c) Tongue helps in thorough mixing of food with saliva.

Question 64:

What are the functions of gastric glands present in the wall of the stomach?

Answer:

(a) Production of pepsin enzyme that digests proteins

(b) Secretion of Mucus for protection of inner lining of stomach.

Question 65:

Match the terms in Column (A) with those in Column (B)

Match the Terms in Column (A) with Those in Column (B) (Q)
Match the terms in Column (A) with those in Column (B) (Q)

Column A

Column B

A

Trypsin

i

Pancreas

B

Amylase

ii

Liver

C

Bile

iii

Gastric glands

D

Pepsin

iv

Saliva

Answer:

Match the Terms in Column (A) with Those in Column (B) (A)
Match the terms in Column (A) with those in Column (B) (A)

Column A

Column B

A

Trypsin

i

Pancreas

B

Amylase

iv

Saliva

C

Bile

ii

Liver

D

Pepsin

iii

Gastric glands

Question 66:

Name the correct substrates for the following enzymes

(a) Trypsin

(b) Amylase

(c) Pepsin

(d) Lipase

Answer:

(a) Trypsin - protein

(b) Amylase - Starch

(c) Pepsin - Proteins

(d) Lipase - Emulsified fats

Question 67:

Why do veins have thin walls as compared to arteries?

Answer:

Arteries carry blood from the heart to various organs of the body under high pressure so they have thick and elastic walls. Veins collect the blood from different organs and bring it back to the heart. The blood is no longer under pressure so the walls are thin with valves to ensure that blood flows only in one direction.

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