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.

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

During inhalation, the air is drawn through the nostrils into the nasal passage. From there, air enters into pharynx, larynx, trachea (windpipe), bronchi, lungs and fnally to the alveoli.

Amylase is the enzyme which helps in primary digestion of starch only.Digestion of starch by salivary amylase into maltose starts in mouth. Oesophagus then pushes the food into stomach.

The oxygen during photosynthesis comes from split water.

Among the given options, Amoeba (binary fssion), Yeast (budding) and banana (vegetative propagation) reproduce by asexual reproduction whereas dogs reproduce by sexual method.

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

The opening and closing of the pore is a function of the guard cells. The guard cells swell when water fows into them, causing the stomatal pore to open. Similarly, the pore closes if the guard cells shrink.