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

The organisms A, B and C can obtain their food in three different ways. Organism A derives its food from the body of another living organism which is called its D, without killing it. The organism B takes in the solid food by the process of ingestion, digests a part of this food and throws out undigested food in the process called E. The organism C obtains its food from dead and decaying plants.

1. What is the mode of nutrition of (i) organism A (ii) organism B, and (iii) organism C?
2. What is the organism like D called?
3. Name the process E.
4. Give one example each of organisms like A, B and C.
5. What is the general name of three modes of nutrition exhibited by organisms A, B and C?

1. Draw a diagram depicting Human Alimentary Canal and label on it, Gall Bladder, Liver and Pancreas.
2. State the roles of Liver and Pancreas.
3. Name the organ which performs the following functions in humans:

1. Absorption of digested food.
2. Absorption of water.

There is a pair of bean-shaped organs P in the human body towards the back, just above the waist. A waste product Q formed by the decomposition of unused proteins in the liver is brought into organ P through blood by an artery R. The numerous tiny filters S present in organ P clean the dirty blood by removing the waste product Q. The clean blood goes into circulation through a vein T. The waste substance Q, other waste salts, and excess water form a yellowish liquid U which goes from organ P into a bag-like structure V through two tubes W. This liquid is then thrown out of the body through a tube X.

1. What is (i) organ P and (ii) waste substance Q?
2. Name (i) artery R, and (ii) vein T.
3. What are tiny filters S known as?
4. Name (i) liquid U, (ii) structure V, (iii) tubes W and (iv) tube X.

How do carbohydrates, fats and proteins get digested in human beings?

Describe the mechanism of urine formation in human excretory system. Draw a labelled diagram to illustrate your answer.

There are four organisms A, B, C and D. The organism A eats only the flesh of other animals as food. The organism B can eat grains, fruits and vegetables as well as meat and fish. The organism C can make the food itself from simple inorganic substances present in the environment by utilising sunlight energy. On the other hand, organism D eats only plants and their products as food.

1. Which organism is

1. Omnivore,
2. Herbivore,
3. Carnivore?

2. Which organism is an autotroph?
3. Which organism is/ are heterotroph (s)?
4. Which organism can be a producer?
5. Which organism is/ are consumer (s)?

Give one example each of organisms which could be like A, B, C and D.

1. Why is there a difference in the rate of breathing between aquatic organisms and terrestrial organisms? Explain.
2. Draw a diagram of human respiratory system and label-pharynx, trachea, lungs, diaphragm and alveolar sac on it.

What is the main difference between aerobic respiration and anaerobic respiration? Give one example of each.

What are the different modes of nutrition? Explain with one example of each mode of nutrition.