The liquid connective tissue A circulates in our body continuously without stopping. This tissue contains a pigment B which imparts it a colour C. The tissue A consists of four components D, E, F and G. The component D fights infection and protects us from diseases. The component E helps in the clotting of tissue A if a person gets a cut. The component F is a liquid which consists mainly of water with many substances dissolved in it and component G carries oxygen from the lungs to all the parts of the body.

1. What is (i) tissue A, (ii) pigment B and (iii) colour C?
2. Name (i) D, (ii) E, (iii) F and (iv) G.
3. Name one substance (other than oxygen) which is transported by tissue A in the human body.
4. Which two components of tissue A are the cells without nucleus?
5. Name any two organisms (animals) which do not have liquid like A in their body.

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

When a person eats sugary food, then organisms A present in his mouth act on sugar to produce a substance B. The substance B first dissolves the calcium salts from the top part C of the tooth and then from its middle part D forming holes E. These holes ultimately reach the part F in the lower part of tooth which contains nerves and blood vessels. The substance B irritates the nerve endings inside the tooth causing toothache.

1. What are (i) organisms A, and (ii) substance B?
2. What are (i) part C, and (ii) part D, of tooth known as?
3. By what name are the holes E in the tooth known?
4. Name the part F of the tooth.
5. What will happen if organisms A reach part F of the tooth known?

What is the difference between excretion and defecation? Explain the process of excretion in humans.

Differentiate between an artery and a vein.

Distinguish between aquatic and terrestrial respiration.

What is lymphatic system? What are its functions?

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

1. List the three events that accur during the process of photosynthesis. Explain the role of stomata in this process.
2. Describe an experiment to show that ''sunlight is essential for photosynthesis.''

Describe the process of urine formation in kidneys.