Plant Growth and Development — BIOLOGY STD 11 Science — Question

Describe the various cell organelles which are covered with membranes.

Why cannot reproduction be consolidated as a defining characteristic of living organisms?

Draw the diagram of a sarcomere of skeletal muscle showing different regions.

Anurag and Amit (students of class XIth) were best friends, one day during the lunch time Anurag gave naashpati (Pyrus) to Amit (as he was fond of that). Amit refused to eat it because he did not like them due to their hardness as compared to apples. Anurag reached home and told her mother (a botanist) that he will also not eat naashpati's. His mother corrected him and told him that he should eat it, as it contains the calcium for the growth of the body.

1. What is the reason for the difference in the softness in apple and naashpati fruits?
2. What are sclereids?
3. What values are inferred from mother's of Anurag's character?

Meiosis is advantageous than mitosis as it produces variations so plays important role in evolution. What are the stages during which chances of recombination of genes are increased during meiosis? Explain these events.

What are the difficulties that you would face in classification of animals, if common fundamental features are not taken into account?

Two common characteristics found in centipede, cockroach and crab, are:

1. Book lungs and antennae.
2. Jointed legs and chitinous exoskeleton.
3. Compound eyes and anal cerci.
4. Green glands and tracheae.

What is complex IV in ETS of mitochondria? Mention its components.

What are the industrial uses of algae?

Write the differences between:
P-wave and T-wave