Science (English Medium) इयत्ता १२ - CBSE Question Bank Solutions

Using various resources such as your school library or the internet and discussions with your teacher, trace the evolutionary stages of any one animal say horse.

Discuss the causes of global warming.

Discuss briefly about greenhouse gases.

Draw a diagram of a section of a megasporangium of an angiosperm and label funiculus, Micropyle, embryosac and nuclleus.

Describe the structure of its microsporangium.

"Man can be a primary as well as a secondary consumer." Justify this statement.

Suggest two advantages to a farmer for using apomictic seeds of hybrid varieties.

Name the greenhouse gases that contribute to global warming.

List the greenhouse gases other than carbon dioxide.

Compare the characteristic features of insect pollinated and wind pollinated flowers. Explain how the respective features assist in pollination.

Answer the following question.
Express the process of pollination in Vallisneria.

Differentiate between geitonogamy and xenogamy (allogamy).

Answer the following question.
Write the difference in the characteristics of the progeny produced as a result of the two processes.

Answer the following question.
List four benefits to human life by eliminating the use of CFC_s.

Can a plant flowering in Mumbai be pollinated by pollen grains of the same species growing in New Delhi? Provide explanations to your answer.

Coelacanth was caught in South Africa. State the significance of the discovery of Coelacanth in the evolutionary history of vertebrates.

1. Nucellus
2. Antipodals
3. Synergids
4. Micropyle

Autogamy can occur in a chasmogamous flower if ______.

Choose the correct statement from the following.

Wind pollination is common in ______.