Transport in Plants — BIOLOGY STD 11 Science — Question

Write an account on skeleton of sponges.

Differentiate between prophase and prophase I.

Plants require water for their survival. But when watered excessively, plants die. Discuss.

List out the advantages of binomial nomenclature.

Draw a standard ECG and explain the different segments in it.

What is the role of sarcoplasmic reticulum, myosin head and F-actin during contraction of striated muscles of humans?

How are muscles classified based on their location? Mention their important functions.

Every nutrient comes from the abiotic component of the ecosystem. These nutrients are converted by green plants into useful substances and finally go to other living beings through the food chain. Finally, after the death of plants and animals; decomposers send them back to the environment. Thus the balance of various components of the ecosystem is maintained. In your view which of the following is the correct approach? What is the importance of balance of ecosystem for us?

1. We should protect the ecosystem so that its balance is maintained.
2. We should enjoy our life and let the nature do its job of maintaining the balance in the ecosystem.

Nutan's grandfather read in the newspaper that, for predicting the identity of criminals or for deciding the controversies regarding biological parents of the child, court always asks for DNA test. He wanted to know the procedure behind it. So, asked Nutan about DNA as she was studying biology in class XI. She replied that it is a substance present in the cells of living organisms which store the information about an individual.

1. According to you, what is DNA? And what percentage of DNA varies from one individual to the other?
2. What are the main constituents of DNA?
3. Why are biologists interested in studying human genome?
4. What values are reflected from Nutan's grandfather behaviour?

How useful is the study of the nature of body cavity and coelom in the classification of animals?