Cell The Unit of Life — BIOLOGY STD 11 Science — Question

Name three groups of plants that bear archegonia. Briefly describe the life cycle of any one of them.

How is a key helpful in the identification and classification of an organism?

An organism has two pair of chromosomes (i.e., chromosome number = 4). Diagrammatically represent the chromosomal arrangement during different phases of meiosis-II.

Biological classification is a dynamic and ever evolving phenomenon which keeps changing with our understanding of life forms. Justify the statement taking any two examples.

What is a tissue? Describe different types of simple tissues in plants.

Distinguish between the following:
Glycolysis and Citric acid cycle

Justify the statement, “Mitochondria are power houses of the cell”.

With the help of suitable diagrams describe mitosis.

Amit went on mountain for trekking. After reaching at about 2000 m height. He experienced difficulty in breathing. His rate of breathing increased and he decided to discontinue the trek and return back to the ground. Being concerned about his health. ls consulted his doctor friend about it? His friend explained that it is a normal phenomenon and he should have carried an oxygen cylinder while going for the trek.

1. Why is it difficult to breathe as we go up on a height?
2. Why does his friend suggested to carry an oxygen cylinder?
3. Which component of blood show its increase when someone moves from plains to higher altitudes?
4. What values are shown by Amit?

Explain various steps involved in cellular respiration.