Science : Ch 06 – Life Processes

The process of digestion begins in the mouth. The mouth contains a digestive enzyme, salivary amylase. This enzyme breaks the starch molecules in the food, into maltose. The absence of amylase in the saliva thus afects the breakdown of starch into simpler sugar molecules.

Bile is secreted by the liver and is stored in the gall bladder from where it enters the small intestine via a common duct.

A nephron is a fltering unit present in kidney. It has diferent parts like Bowman’s capsule, glomerulus and tubular region (Renal tubule). Glucose, amino acids and salts are selectively reabsorbed in tubular region.

Pseudopodia are developed in amoeba. Amoeba engulfs its food particles by forming pseudopodia around it. The food particle gets surrounded by encircling pseudopodia’s tips.

Anaerobic respiration (in absence of oxygen) in yeast is known as fermentation as ethanol (alcohol), carbon dioxide and 2 ATP molecules of energy is produced from glucose

Valves prevent backward fow of blood as they are located at each end of two ventricles and act as one way inlet.

The anterior vena cava collects deoxygenated blood from the head, chest, and arms and enters the right atrium while the inferior vena cava collects blood from the lower body regions_x000D__x000D_Left atrium receives oxygenated blood from diferent parts of body while right atrium receives deoxygenated blood from lungs_x000D_Left ventricle pumps oxygenated blood to diferent body parts while right ventricle pumps deoxygenated blood to lungs_x000D_Left atrium transfers oxygenated blood to right ventricle which sends it to diferent body parts_x000D_Right atrium receives deoxygenated blood from diferent parts of the body while left ventricle pumps oxygenated blood to diferent parts of the body

The oxygen during photosynthesis comes from split water.

The blood leaving the tissues becomes richer in carbon dioxide. When the oxygenated blood passes through the capillaries of the tissue.

Steps of photosynthesis are as follows: (i) Absorption of light energy by chlorophyll. (ii) Conversion of light energy to chemical energy and splitting of water molecules into hydrogen and oxygen. (iii) Reduction of carbon dioxide to carbohydrates.