Nutrition - 1 (Class IX)

Elements used in large quantities by the plant are termed macronutrients, which can be further defined as primary and secondary. The primary nutrients include nitrogen (N), phosphorus (P) and potassium (K). These elements contribute to plant nutrient content, function of plant enzymes and biochemical processes, and integrity of plant cells. Deficiency of these nutrients contributes to reduced plant growth, health and yield. Thus, they are the three most important nutrients supplied by fertilizers. The secondary nutrients include calcium (Ca), magnesium (Mg) and sulphur (S).

Pitcher plant is named so because in this plant, the leaves are modified to take up the shape of pitcher in order to trap the insects.

The upper surface of the tongue has small projections called papillae. This is the correct option.

This is the correct option. Hepatic duct (from the liver) and cystic duct (the duct of gall bladder) together form the common bile duct.

This is the correct option. The parotid glands are located in the cheek. The sub-maxillary glands are located in the lower jaw. The sub-lingual glands are located below the tongue.

When phosphorus is deficient, growth is reduced and leaves fall off prematurely. Plants lacking phosphorus produce dull, bluish-green leaves that turn a purplish or bronze colour with brown edges.

Rhizobia is “the group of soil bacteria that infect the roots of legumes to form root nodules”. Rhizobia are found in the soil and after infection, they produce nodules in the legume where they fix nitrogen gas (N₂) from the atmosphere, turning it into a more readily useful form of nitrogen (N). From here, the nitrogen is exported from the nodules and used for growth in the legume. Once the legume dies, the nodule breaks down and releases the rhizobia back into the soil where they can live individually or reinfect a new legume host.

The salivary amylase or ptyalin present in saliva converts starch into maltose.

The opening of the stomach into the intestine is called pylorus. It has a ring of muscles called sphincter.

This is the correct option. Liver secretes bile juice which plays an important role in the digestion of fats.

This is the correct option. Stomach is an organ where a major part of the digestion of food happens. Stomach secretes hydrochloric acid.

Scurvy is due to the deficiency of ascorbic acid.

Lactose is a disaccharide present in the milk of mammals. It is a readily digestible source of glucose (energy) for the neonate. 

 Chlorine helps in the photolysis of water. Photolysis is part of the light-dependent reactions of photosynthesis.

Two groups of organisms can live together in a mutual way, i.e. they benefit one in one respect and get benefited from the other in another respect. Such mode of sharing shelter and nutrition in two groups of organisms is known as symbiotic mode of nutrition.