Breathing and Exchange of Gases — BIOLOGY STD 11 Science — Question

Which one of the following groups of animals is correctly matched with its one characteristic feature without even a single exception?

1. Mammalia : give birth to young ones.
2. Reptilia : possess 3-chambered heart with one incompletely divided ventricle.
3. Chordata : possess a mouth provided with an upper and a lower jaw.
4. Chondrichthyes : possess cartilaginous endoskeleton.

How important is the presence of air bladder in Pisces?

Describe the various cell organelles which are covered with membranes.

Tube feet occur in:

1. Cockroach.
2. Starfish.
3. Cuttle fish.
4. Cat fish.

Biology teacher while taking class on respiration, told students that respiration is the characteristic feature of living beings, whether it is plant or animal. Ankita listened this, argued with her teacher and asked that plants do not have any structures for respiration then how can they respire. Teacher was impressed by Ankita's question and explained the students about respiration in plants.

1. In which cell organelle does respiration take place?
2. What compound is known as energy currency of the cell?
3. Where does aerobic and anaerobic respiration take place in a cell?
4. Which good quality is possessed by Ankita and her teacher?

What are porins? What role do they play in diffusion?

Which hormonal deficiency is responsible for the following?

1. Diabetes mellitus.
2. Cretinism.

Write one symptom for each deficiency.

If the critical photoperiod for a short-day plant is 13hrs of daylight, will it flower when there are 15hrs of daylight?

It is absolutely not necessary to produce amylase in an inactive form in our body, but it is not so in the case of trypsin. Give reason.

Answer the following questions based upon the given figure.

1. What type of division is this? Whether meiotic or/and mitotic and which stage?
2. What is A and B?