Plant Growth and Mineral Nutrition — BIOLOGY STD 12 Science — Question

What is an incomplete ecosystem? Explain with the help of suitable example.

Enlist the role of following minerals and the symptoms caused due to their deficiency : (a) Calcium (b) Boron and (c) Chlorine.

Name the sperm lysin, which organelle secretes it? What is its function?

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.

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?

1. Explain any two defence mechanisms plants evolved against their predators.
2. How does predation differ from parasitism?

Mutations are beneficial for plant breeding. Taking an example, justify the statement.

How does tongue detect the sensation of taste?

Give a schematic representation of oogenesis in humans. Mention the number of chromosomes at each stage. Correlate the life phases of the individual with the stages of the process.

It is commonly observed that parents feel embarrassed to discuss freely with their adolescent children about sexuality and reproduction. The result of this parental inhibition is that the children go astray sometimes.

1. Explain the reasons that you feel are behind such embarrassment amongst some parents to freely discuss such issues with their growing children.
2. By taking one example of a local plant and animal, how would you help these parents to overcome such inhibitions about reproduction and sexuality?