Biological Classification — BIOLOGY STD 11 Science — Question

(i) If intense light is shown on a plant at short intervals, then its photosynthetic yield per second will be more than that of a plant on which the intensity of light falls continuously and equally, explain. (ii) Make a labelled diagram of a section of green chloroplast.

What are the main differences among Chlorophyceae, Phaeophyceae and Rhodophyceae?

Explain with examples the categories determined on the basis of nitrogenous excreting substances.

Describe the type of photosynthetic pigments in red algae, green algae and brown algae.

Draw a diagram showing comparison of diploblastic and triploblastic organization.

Honeybees lead a highly socially organized life and thus are able to convert the nectar into sweet honey. Which of the following is similar to this statement? Which type of benefits those animals get which live a social life?

1. If we learn to cooperate among ourselves then we can create immense value not only for us but also for others
2. Teamwork is a dream-work
3. All human beings are dependent on each other for their survival

A rubber band stretches and reverts back to its original position. Bubble gum stretches, but it would not return to its original position.
Is there any difference between the two processes? Discuss it with respect to plant growth (Hint: Elasticity (reversible) Plasticity (irreversible)).

Differentiate between an Insect and Spider.

What are root hairs? Which region of the root do they arise from? What is their function?

(i) In aerobic respiration the respiratory coefficient is infinite. Please explain.
(ii) Define the following: (a) Floating respiration (b) Protoplasmic respiration (c) External respiration (d) Internal respiration.