MODEL PAPER 4 — BIOLOGY STD 11 Science — Question

Photosynthetic organisms occur at different depths in the ocean. Do they receive qualitatively and quantitatively the same light? How do they adapt to carry out photosynthesis under these conditions?

Write the differences between: Blood and Lymph.

What is the structural formula of sugars?

State economically important uses of: heterotrophic bacteria

Differentiate between keratinised and non-keratinised stratified squamous epithelia.

Give the scientific terms for the following:

1. Loss of water from leaves through stomata in the form of water vapour.
2. Movement of water in roots exclusively through the cell wall.
3. Water adsorbed by solids, causing them to enormously increase in volume.

Give one example each of Chlorophyceae, Phaeophyceae and Rhodophyceae.

Write any four differences between mitosis of animal and plant cells.

It has been observed that some plants need periodic exposure to light to induce flowering. This phenomenon is called photoperiodism. How does sunlight affect the human life?

Ankita prepared hard for the test at home. All text based question and one practical based question on lock and key hypothesis was given to check whether the students had understood the phenomenon or not. Ankita who was a topper of class was the only student who was able to solve the problem. All others were unable to attempt the same. Teacher felt happy and asked Ankita to explain the process in the class.

1. Who proposed the lock and key hypothesis?
2. What is the nature of enzyme action?
3. Why are enzymes also called biocatalyst?
4. What values are reflected from Ankita's character?
5. The hypothesis was given by Emil Fischer in 1894.