Inheritance and Variation — BIOLOGY STD 12 Science — Question

Compare in any three ways the chromosomal theory of inheritance as proposed by Sutton and Boveri; with that of experimental results on pea plant presented by Mendel.

Write the differences between wind-pollinated and insect-pollinated flowers. Give an example of each type.

Write a short note on
Effects of temperature or water scarcity and the adaptations of animals

1. A DNA segment has a total of 1000 nucleotides, out of which 240 of them are adenine containing nucleotides. How many pyrimidine bases this DNA segment possesses?
2. Draw a diagrammatic sketch of a portion of DNA segment to support your answer.

A number of passengers were severely burnt beyond recognition during a train accident. Name and describe a modern technique that can help hand over the dead to their relatives.

Taking the example of white-winged moths and dark-winged moths of England in pre and postindustrialised era, explain evolution by natural selection.OR
How can evolution by natural selection be explained by melanised moths before and after industrialisation in England?OR
How did industrialisation play a role in Natural Selection of light and dark-coloured moth in England?OR

What do these pictures (a) and (b) illustrate with reference to evolution? Explain.

How do organisms like fungi, zooplanktons and bears overcome the temporary short-lived climatic stressful conditions? Explain.

1. Give the scientific name of the soil bacterium which produces crystal (Cry) proteins.
2. How are these proteins useful in agriculture?
3. What do the differently written terms ‘Cry’ and ‘cry’ represent respectively?

What is asexual reperoduction? Describe fragmentation.

Differentiate between divergent and convergent evolution. Give one example of each.