Science (English Medium) Class 11 - CBSE Question Bank Solutions for Biology

Define the following term:

Superior ovary

Take one flower each of families Fabaceae and Solanaceae and write its semi-technical description. Also, draw their floral diagrams after studying them.

Write the floral formula of an actinomorphic bisexual, hypogynous flower with five united sepals, five free petals. Five free stamens and two united carpals with superior ovary and axile placentation.

Draw illustrations to bring out anatomical difference between Monocot root and dicot root.

What are the conditions necessary for fixation of atmospheric nitrogen by Rhizobium. What is their role in N₂ -fixation?

What are the steps involved in formation of a root nodule?

Look at leaves of the same plant on the shady side and compare it with the leaves on the sunny side. Or, compare the potted plants kept in the sunlight with those in the shade. Which of them has leaves that are darker green? Why?

List the hormones secreted by the following:

G-I Tract.

An association between roots of higher plants and fungi is called ______.

A dikaryon is formed when ______.

With respect to fungal sexual cycle, choose the correct sequence of events ______.

There is a myth that immediately after heavy rains in forest, mushrooms appear in large number and make a very large ring or circle, which may be several metres in diameter. These are called as ‘Fairy rings’. Can you explain this myth of fairy rings in biological terms?

Fungi are cosmopolitan. Write the role of fungi in your daily life.

A transverse section of stem is stained first with safranin and then with fast green following the usual schedule of double staining for the preparation of a permanent slide. What would be the colour of the stained xylem and phloem?

The arrangement of ovules within the ovary is known as placentation. What does the term placenta refer to? Draw various types of placentations in the flower as seen in T.S. and V.S.

Distinguish between the following:

Stele and vascular bundle

Mycorrhiza is a symbiotic association of fungus with root system which helps in ______.

1. Absorption of water
2. Mineral nutrition
3. Translocation
4. Gaseous exchange

Comment on the experimental setup

1. What does the setup demonstrate?
2. What will happen to the level of water if a blower is placed close to setup.
3. Will the mercury level fluctuate (go up/down) if phenyl mercuric acetate is sprayed on leaves?

Reaction carried out by N₂ fixing microbes include

1. \[\ce{2NH3 + 3O2 -> 2NO^{-}2 + 2H^{+} + 2H2O (i)}\]
2. \[\ce{2NO^{-}2 + O2 -> 2NO^{-}3 (ii)}\]

Which of the following statements about these equations is not true

With regard to the Biological Nitrogen Fixation by Rhizobium in association with soybean, which one of the following statement/ statements does not hold true.