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

The human body has an organ A which acts as a double pump. The oxygenated blood coming from the lungs through a blood vessel B enters the upper left chamber C of the double pump. When chamber C contracts, then blood goes into lower left chamber D. The contraction of chamber D forces the blood to go into a blood vessel E which supplies oxygenated blood to all the organs of the body (except the lungs). The deoxygenated blood coming out of the body organs is taken by a blood vessel F to the right upper chamber G of pumping organ. Contraction of chamber G forces the deoxygenated blood into right lower chamber H. And finally the contraction of chamber H sends the deoxygenated blood into lungs through a blood vessel I.

1. What is organ A?
2. Name the blood vessel (i) B (ii) E (iii) F, and (iv) I.
3. What are chambers (i) C, and (ii) D?
4. What are chambers (i) G and (ii) H?

Draw a labelled diagram of:

1. A xylem vessel.
2. A sieve tube (or phloem).

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

Platelets help in clotting of blood at injured side. Draw a flow diagram of this process.

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.

State one difference between artificial kidney and natural kidney?

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.

Why do we need a proper transportation system in plants?