CBSE Questions for Class 11 Medical Biology Digestion And Absorption Quiz 1 - MCQExams.com

• Hydrolases catalyze hydrolytic reactions. Some of the important hydrolases include amylases, sucrase, lactase, maltase, protease, esterase etc. 
• Amylase catalyzes the hydrolysis of starch (polysaccharide form of glucose) into maltose (a disaccharide of glucose).

• Carbohydrate digestion begins in the mouth. The salivary glands in the mouth secrete saliva, which helps to moisten the food.
• The food is then chewed while the salivary glands also release the enzyme salivary amylase, which begins the process of breaking down the polysaccharides in the carbohydrate food.
• But this activity is much less important than that of pancreatic amylase in the small intestine which digests carbohydrates. Hence, Digestion of starch takes place in the buccal cavity and small intestine.

1. Diarrhea is the condition of having at least three loose or liquid bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss.
2.  Signs of dehydration often begin with loss of the normal stretchiness of the skin and irritable behavior. This can progress to decreased urination, loss of skin color, a fast heart rate and a decrease in responsiveness as it becomes more severe. 
3. These infections are often acquired from food or water that has been contaminated by feces, or directly from another person who is infected. Hence, the mode of infection of diarrhea is food.
   

• The bile duct and the pancreatic duct open together into the duodenum as the common hepato-pancreatic duct, which is guarded by the Sphincter of Oddi. 
• Semilunar valves are found in at the points where pulmonary artery and aorta leave the heart. These valves prevent blood from getting back into the ventricles. 
• Ileocaecal valve is present at the opening of large intestine. It prevents the backward flow of the faecal matter. 
• Pyloric sphincter regulates the opening of stomach into duodenum .
• Hence, Option A is correct. 

• Absorption is the process by which the products of digestion are absorbed by the blood to be supplied to the rest of the body. 
• During absorption, the digested products are transported into the blood or lymph through the mucous membrane. Hence, Absorption is defined as the passage of nutrients from the gastrointestinal tract into the bloodstream.

Then there is submucosa which is then followed by the innermost layer of mucosa. The mucosa is the epithelial membrane lining the lumen of the alimentary canal.

• The alimentary canal is made up of smooth muscles which are involuntary and controlled by the autonomic nervous system. 
• Single-unit smooth muscles are present in the alimentary canal and they can contract regularly without input from a motor neuron (myogenic) as opposed to multi-unit smooth muscle, which is neurogenic - that is, its contraction must be initiated by an autonomic nervous system neuron (neurogenic).
  
• Hence, muscles of the alimentary canal are chiefly unstriated and myogenic.

• The four basic kinds of tastes are: sweet, salty, sour and bitter. 
• The salty/sweet taste buds are located near the front of the tongue.
• The sour taste buds line the sides of the tongue.
• Bitter taste buds are found at the back of the tongue. 
• The centre of the tongue has few taste buds. 

• The presence of milk-producing glands (mammary glands), external and middle ears, two pairs of limbs, and skin with hair are some of the characteristic features of mammals. 
• Most vertebrates, except mammals, have homodont teeth (anatomically and functionally similar teeth) while mammals possess heterodont teeth (different types of teeth with different functions). 

• The pylorus is a narrow cone-shaped constriction present at the end of the stomach and the beginning of the small intestine. 
• It contains two regions antrum which connects the parts of the stomach and the pyloric canal which connects the stomach and small intestine. 
• The main function of the pylorus is to prevent intestinal contents from re-entering the stomach when the small intestine contracts to limit the passage of large food particles or undigested material into the intestine.