The process of breakdown of food in the cell with the release of energy is called cellular respiration. Diverse organisms do this in different ways – some use oxygen to break-down glucose completely into carbon dioxide and water, some use other pathways that do not involve oxygen.

Name the nutrients which are completely digested in the small intestine.

Most of the digestive enzymes in the small intestine are secreted by the pancreas and enter the small intestine via the pancreatic duct. The three major classes of nutrients that undergo complete digestion in the small intestine are proteins, lipids (fats), and carbohydrates.

What is the role of (1) teeth and (2) tongue in digestion?

(1) Teeth - When the food is consumed in the mouth, the teeth break the food into smaller pieces. This process is also known as mastication – the process of cutting, tearing, and grinding the food in the mouth and mixing it with the saliva, so it can be swallowed easily before it enters the body. (2) Tongue - The tongue helps out, pushing the food around while chewing with the teeth. When ready to swallow, the tongue pushes a tiny bit of mushed-up food called a bolus towards the back of the throat and into the opening of the oesophagus, the second part of the digestive tract.

Name the main organs of the human digestive system in the order to the digestion of food.

Digestion is the process by which large insoluble food molecules are broken down into little water-soluble food molecules that may be absorbed into the watery blood plasma. The main organs of the human digestive system in order to the digestion of food are the mouth, oesophagus, stomach, small intestine, large intestine, rectum, and anus. It also contains the salivary glands, liver, gallbladder, and pancreas, which produce digestive juices and enzymes that aid in the digestion of food and liquids. The digestive system's six primary functions are ingestion, propulsion, mechanical breakdown, chemical digestion, absorption, and excretion or elimination.

Elimination of storage and waste products are completely different in case of plants. Justify the statement.

Metabolism occurs in the cells of living organisms, producing both helpful and poisonous chemicals. Toxin buildup can be harmful to the organism. As a result, living creatures excrete all of these metabolic wastes from their bodies, a process known as excretion. Animals, for example, have a highly developed and specialised excretory system. Plants, on the other hand, lack a well-developed excretory system like animals. They do not have any excretory organs. As a result, excretion in plants is not as complicated. Plants create many excretory products as a result of cellular respiration, photosynthesis, and other metabolic activities. The principal excretory products in plants are carbon dioxide, excess water produced during respiration, and nitrogenous chemicals created during protein metabolism. Plants emit two types of gaseous waste products: oxygen during photosynthesis and carbon dioxide during respiration. Plants excrete gaseous waste through stomatal holes on their leaves. The oxygen produced by photosynthesis is utilised for respiration, whereas the carbon dioxide produced by respiration is used for photosynthesis. Water is also expelled from the plant body via stomatal holes on the surfaces of fruits and stems. The process of removing water is known as transpiration. Waste products such as gums, oils, latex, resins, etc., are stored in plant components such as barks, stems, and leaves. Plants eventually shed these components. They will occasionally defecate into the earth. Excretion in aquatic plants takes place through diffusion. Hence, the elimination of storage and waste products are completely different in the case of plants.

What are the two basic raw materials for photosynthesis other than light?

Photosynthesis is a process through which autotrophs make their food in the presence of sunlight and chlorophyll. The two basic raw materials for photosynthesis other than light are carbon dioxide and water

List two events which occur during photosynthesis.

The two events that occur during the process of photosynthesis are: Chlorophyll absorbs solar energy and converts carbon dioxide to carbohydrates. Light energy is converted to chemical energy, and water molecules are broken into hydrogen and oxygen.