Microbes in Human Welfare — BIOLOGY STD 12 Science — Question

Write the names of two dinosaurs that lived early in the history of earth and two others that lived little later.

What are chromatin? Why are they seen as ‘beads on string’ structure under electron microscope?

How does the sperm penetrate through the zona pellucida in human ovum?

Name the technology used in micropropagation of plants. Write the genetic significance of the plants raised through this technique. Give two cxamples, where this technology is commercially exploited.

What are the major components of seminal plasma?

The species diversity of plants (22 per cent) is much less than that of animals (72 per cent). What could be the explanations to how animals achieve greater diversification ?

Name the type of fruit, apple is categorised under and why? Mention two other examples, which belong to the same category as apple.

Discuss with your teacher and find out how to distinguish between:
Plasmid DNA and Chromosomal DNA

List the different types of pollination depending upon the source of pollen grain.

Why do high altitude areas have brighter sunlight and lower temperatures as compared to the plains?