Microbes in Human Welfare — BIOLOGY STD 12 Science — Question

1. Differentiate between analogous and homologous structures.
2. Select and write analogous structures from the list given below:

1. Wings of butterfly and birds.
2. Vertebrate hearts.
3. Tendrils of bougainvillea and cucurbita.
4. Tubers of sweet potato and potato.

Study the following diagram, and answer these questions:

1. Why does a wide arrow point from both producers and consumers to decomposers?
2. Why does a wide arrow point only from inorganic nutrient pool to producers?
3. Why don't the wavy arrows point from decomposers to producers?

Write two contrivances found in selfpollinated flower.

How do mycorrhizal fungi help the plants harbouring them?

Write three differences between DNA and RNA.

How many chromosomes are present in a human male sperm?

Describe the effects of malaria on the human body.

1. Write the importance of measuring the size of a population in a habitat or an ecosystem.
2. Explain with the help of an example how the percentage cover is a more meaningful measure of population size than more numbers.

If implementation of better techniques and new strategies are required to provide more efficient care and assistance to people, then why is there a statutory ban on amniocentesis? Write the use of this technique and give reason to justify the ban.

A schematic diagram of matured human insulin is given below:

How is the process of its formation naturally in the human body different from that of its formation by rDNA technology? Explain.