Respiration is a chemical process where oxygen is taken in and which reacts chemically with food in the body and metabolize it and release carbon dioxide and energy. The energy released during respiration is essential for the survival of the organism.

Which nutritive element is found in abundance in fish?

Fish is a vital source of food for people. Fish is an important source of protein. Fish proteins are regarded as 'easily digestible' protein. Proteins are required for growth and repair of our body. Fish is rich in calcium and phosphorus and a great source of minerals, such as iron, zinc, iodine, magnesium, and potassium. It is also one of the source of vitamin A and D. Fish contain omega- 3 fatty acids and riboflavin.

Draw a labelled diagram of human excretory system.

Excretion is the process of removal of metabolic wastes from the body. Human beings and other mammals are ureotelic organisms as they excrete urea in the form of urine as an excretory material.

Explain the mechanism of glomerular filtration in urine formation

Glomerular filtration occurs in the glomerulus where blood is filtered. This process occurs across the three layers- epithelium of Bowman’s capsule, endothelium of glomerular blood vessels, and a membrane between these two layers. The glomerulus is a complex network of blood capillaries that is surrounded by Bowman's capsule. It occurs at the barrier between the blood and the filtrate in the glomerular capsule in the kidneys. The pressure of blood and concentration gradients lead to a separation of components through a semipermeable membrane. The product of ultrafiltration is the glomerular filtrate that contains excess water, salts, ions, nitrogenous waste, and nutrients.

The living organisms produce various waste products such as uric acid, carbon dioxide, urea, ammonia, etc as a result of various metabolic reactions taking place in their bodies. The process of removal of wastes from the body is called excretion.