Microbes in Human Welfare — BIOLOGY STD 12 Science — Question

(a) Name the hormone which is responsible for apical dominance.
(b) A farmer wants to remove broad-leaved weeds from the jawar plantation in his field. Suggest any plant hormone to remove such weeds.
(c) Mention any two applications of cytokinin.

Given below is the representation of amino acid composition of the relevant translated portion of B-chain of haemoglobin, related to the shape of human red blood cells.

1. Is this representation indicating a normal human or a sufferer from certain related genetic disease? Give reason in support of your answer.
2. What difference would be noticed in the phenotype of the normal and the sufferer related to this gene?
3. Who are likely to suffer more from the defect related to the gene representedthe males, the females or both males and females equally? And why?

Name and explain the role of inner and middle walls of the human uterus.

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

Study the given pedigree chart and answer the questions that follow:
Give the genotypes of the parents in generation I and of their third and fourth child in generation II.

What are the characteristic symptoms of Down’s syndrome?

Describe the development of dicot embryo in flowering plants.

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 achieved greater diversification?

During a biology lecture in class the teacher called apple seeds as seeds but maize seeds as grains. On hearing this Amit got confused and asks her teacher the reason behind this. The teacher appreciated Amit and cleared all his doubts.

1. What is the difference between seed and grain?
2. How are maize grains formed?
3. Explain along with a labelled diagram of the vertical section of a maize grain.
4. What values are shown by Amit?