Write the events that occur during the process of breathing in humans.

Describe the structure and functioning of nephrons.

There are five animals P, Q, R, S and T. The animal P always lives in water and has gills for breathing. The animal Q can stay in water as well as on land and can breathe both, through moist skin and lungs. The animal R lives in soil and breathes only through its skin. The animal S lives on land and breathes through spiracles and tracheae. And animal T lives in water and breathes through its cell membrane.

1. Which of the animals could be Amoeba?
2. Which of the animals could be frog?
3. Which animal could be fish?
4. Which animal could be grasshopper?
5. Which animal could be earthworm?

Where does anaerobic respiration occur in human body?

Classify the following into herbivores, carnivores and omnivores:
Lion, Man, Dog, Goat, Crow, Elephant, Snake, Hawk, Rabbit, Deer.

1. Draw a sectional view of the human heart and label on it, Aorta, Right Ventricle and Pulmonary Veins.
2. State the functions of the following components of transport system:

1. Blood.
2. Lymph.

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

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?

The process of ultra-filtration is essential in urine formation, where does this step occur in nephron?

Explain the process of breathing in man.