Animal Kingdom — BIOLOGY STD 11 Science — Question

Write the names of the excretory organs of the followinganimals: (i) Flatworms, (ii) Earthworm, (iii) Cockroach, (iv) Hydra, (v) Balanoglossus, (vi) Rat.

Draw a diagram and describe the human excretory system.

Why is the colour of a leaf kept in the dark frequently yellow, or pale green? Which pigment do you think is more stable?

Amrita was very fond of rice pudding. She told her mother to put raisins in pudding. When her mother served her pudding she saw that raisins that her mother added while preparing the dish had swollen up. She got surprised and asked her father (biology tutor) the reason behind this. Her father told that swelling of raisins had occurred due to the phenomenon of osmosis.

1. Mention the importance of osmosis in plants).
2. What is the logic behind the process of osmosis in swelling of raisins.
3. Describe osmotic pressure.
4. What values of Amrita reflect from this case.

Explain geometric growth in plants.

What causes the opening and closing of guard cells of stomata during transpiration?

Is there a species or region specific type of plastids? How does one distinguish one from the other?

What are taxonomical aids? Give the importance of herbaria and museums. How are Botanical gardens and Zoological parks useful in conserving biodiversity?

Calcium ion concentration in blood affects muscle contraction. Does it lead to tetany in certain cases? How will you correlate fluctuation in blood calcium with tetany?

Bring out the differences between plant cells and animal cells.