Student Corner

1. In Human beings the process of digestion of food begins in:
   A. Stomach
   B. Food Pipe
   C. Mouth
   D. Small Intestine
   Ans. C
   Explanation: Digestion of food starts as soon as we put food in our mouth. The mouth cavity contains teeth, tongue and salivary glands. The teeth cut the food into small pieces, chew and grind it. The teeth help in physical digestion. The salivary glands help in chemical digestion by secreting enzymes.
2. Which of the following organism have parasitic mode of nutrition?
   A. Penicillium
   B. Plasmodium
   C. Paramecium
   D. Parrot
   Ans. B
   Explanation: In parasitic nutrition organism derives its food from the body of another living organism called host without killing it. Parasitic mode of nutrition is observed in several fungi, bacteria, few plants like Cuscuta and some animals like Plasmodium and round worms. Plasmodium causes malarial disease.
3.  Name the first enzyme that mix with food in the digestive tract?
   A. Pepsin
   B. Trypsin
   C. Amylase
   D. None of the above
   Ans. C
   Explanation: The salivary glands present in mouth secrete salivary amylase enzyme which digests the starch present in food into sugar. Digestion of starch or carbohydrate starts in mouth itself. Therefore, amylase is the first enzyme that helps in the process of digestion.
4.  Which of the following in biology is the energy currency of cells?
   A. PDP
   B. DTP
   C. ATP
   D. ADP
   Ans. C
   Explanation: The process of releasing energy from food is called respiration. The energy is stored in the form of ATP (Adenosine tri phosphate) in the body cells which is used for various purposes like contraction of muscles, conduction of nerve impulses, synthesis of proteins and many other activities related to the functioning of cells. Therefore, ATP is known as the energy currency of cells.
5.  In the stem of a plant respiration and breathing takes place through:
   A. Lenticels
   B. Stomata
   C. Root hair
   D. Air tubes
   Ans. A
   Explanation:  In woody stems of plants or trees have lenticels for the exchange of respiratory gases.

How Plants and Animals are sensitive to pH Changes?
6. Which animal has three-chambered heart?
A. Pigeon
B. Lizard
C. Fish
D. Lion
Ans. B
Explanation: Lizard has three-chambered heart. Except crocodiles all the reptiles and have three-chambered heart. Crocodiles have four-chambered heart. Pigeons have four-chambered heart. Fish have two-chambered heart. Lion have four-chambered heart.
Birds and mammals have four chambered heart i.e. 2 atria and 2 ventricles. Three-chambered consists of 2 atria and 1 ventricle and two-chambered heart consists of 1 atria and 1 ventricle.

7.  Name the blood vessel which carries blood back to the heart?
A. Vein
B. Artery
C. Capillaries
D. Platelet
Ans. A
Explanation: Arteries carries blood from the heart to the body organs and veins carries blood from the body organs back to the heart.

8. Transportation of food in plants takes place through:
A. Xylem
B. Phloem
C. Companion cells
D. Tracheids
Ans B
Explanation: Plants have two tissues that help in transportation. Xylem transports water and solutes from the roots to the leaves while phloem transports food from the leaves to the rest of the plant. 

9. After wound or cut in a body blood coagulates through:
A. WBC
B. RBC
C. Platelets
D. Plasma
Ans. C
Explanation: After wound or cut in a body it starts to bleed. But within few seconds or minutes blood cells start to clump together and clot, preventing the further blood loss. These clots are created by a type of blood cell called platelet.

10. When blood is forced into the artery, wave like expansion takes place is called:
A. Heart beat
B. Pulse
C. Flow
D. Ticking
Ans. B
Explanation: The expansion of an artery each time the blood is forced into it is called pulse. The pulse rate of an adult person while resting is 70 to 72 per minute.
From the above quiz we have seen various life processes that take place in an organism.