Excretion is different in multi-cellular organisms as compared to unicellular organisms. How?

1. Draw a diagram of excretory system in human beings and label on it: Aorta, Vena cava, Urinary bladder, Urethra.
2. List two vital functions of the kidney.

A liquid X of colour Y circulates in the human body only in one direction: from body tissues to the heart. Among other things, liquid X contains germs from cells and dead cells. The liquid X is cleaned of germs and dead cells by a special type of white blood cells called Z. This cleaned liquid is then put into blood circulatory system in subclavian veins.

1. What is (i) liquid X and (ii) colour Y?
2. What are Z.
3. The liquid X is somewhat similar to a component of blood. Name this component.
4. Why is liquid X not red?

During the respiration of an organism A, 1 molecule of glucose produces 2 ATP molecules whereas in the respiration of another organism B, 1 molecule of glucose produces 38 ATP molecules.

1. Which organism is undergoing aerobic respiration?
2. Which organism is undergoing anaerobic respiration?
3. Which type of organism, A or B, can convert glucose into alcohol?
4. Name one organism which behaves like A.
5. Name two organisms which behave like B.

Describe the flow of blood through the heart of human beings.

Explain the digestion of chapati in human beings. Draw a diagram depicting human alimentary canal.

Differentiate between an autotroph and a heterotroph.

1. Mention any two components of blood.
2. Trace the movement of oxygenated blood in the body.
3. Write the function of valves present in between atria and ventricles.
4. Write one structural difference between the composition of artery and veins.

A unicellular animal P having no fixed shape ingests a food particle by forming temporary finger-like projections Q. The food particle is engulfed with a little surrounding water to form a temporary stomach R inside it. The chemicals S from surrounding cytoplasm enter into R and break down food into small and soluble molecules by chemical reactions. The digested food is absorbed directly into cytoplasm by the process T. The undigested food is thrown out of the body by the rupture of a cell organelle U in a process called V.

1. Name the unicellular animal P.
2. What are (i) Q, and (ii) R?
3. Name (i) chemical S, and (ii) process T.
4. Name (i) organelle U, and (ii) process V.

Some sugar solution is taken in a test-tube and a little of substance X in powder form is added to it. The mouth of test - tube is closed with a cork and allowed to stand for sometime. On opening the cork, a characteristic smell of substance Y is obtained and a gas Z is also observed to be formed. The gas Z extinguishes a burning matchstick.

1. What could be X, Y and Z?
2. What is the process of converting sugar into substance Y by the action of X known as?
3. What type of respiration is exhibited by X in the above process?