The Living World — BIOLOGY STD 11 Science — Question

Neha was walking in the garden early morning and observed many beautiful flowering plants. She got attracted by the brightly coloured flowers and their beautiful appearance. Neha was curious to know about the variation of colours in flowers and asked her biology teacher about this. Teacher told her about the plastids found in only plant cells.

1. Which plastids are found in flowers and fruits?
2. Which plastids are known as kitchen of the cell?
3. Name the colourless plastids.
4. What values are shown by Neha?

List the various types of nephridia in earthworm. Briefly describe the functioning of nephridia during excretion.

Write the types of following structures in mammals:

1. Kidneys
2. Fertilisation
3. RBCS
4. Brain
5. Parental care
6. Sexual dimorphism

Describe the pectoral girdle of human skeleton.

Why is the term short-day plants a misnomer? Give one example of short-day plants.

With the help of proper diagram describe various regions of root.

Write the name of three parasitic protozoans.

Endoparasites are found inside the host body. Mention the special structure, possessed by these and which enables them to survive in those conditions.

Describe three reasons for the generation of a proton gradient between the lumen of thylakoids and the stroma of chloroplasts.

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.