Biological Classification — BIOLOGY STD 11 Science — Question

What is periderm? How does periderm formation take place in the dicot stems?

Why is the colour of a leaf kept in the dark frequently yellow, or pale green? Which pigment do you think is more stable?

Write any four differences between phycomycetes and ascomycetes.

Explain the basic structure of an Amino acid.

What do you understand by binomial system? Please clarify by example.

Explain the following events of a cardiac cycle.

1. Atrial systole.
2. Ventricular systole.
3. Ventricular diastole.

Arya went to a bird sanctuary with her family. She saw numerous birds there and was amazed by the colourful and vibrant world of flying birds. She also saw ostriches there but they were not flying seeing this, she asked her mother who is an ornithologist) why only birds can fly, while all other animals cannot. She also asked her mother about the birds that cannot fly.

Her mother explained Arya about birds and their characteristic features. Arya felt happy knowing knowledge:

1. Which characteristic features of Aves.
2. What are the flight adaptations of birds?
3. Name few flightless birds.
4. What values are shown by Arya?

A gardener finds some broad-leaved dicot weeds growing in his lawns. What can be done to get rid of the weeds efficiently?

What is the difference between direct and indirect development?

Explain differentiation by giving one example.