Amoeba is a living matter and a sand particle is non-living matter.Explain.

3

(a)

Why reproduction is necessary? is it essential for survival? If a living organism does not reproduce, in which category it will belong, living or non-living? How is sexual reproduction different from asexual reproduction?

3

(a)

Do you consider a person in coma, living or dead?

3

(a)

In which conditions human beings are difficult to define as living?

3

(a)

When did cyanobacteria evolved? Why are they referred  as the earliest colonisers of barren areas?

3

(a)

Justify the statement Euglena is a  taxonomic puzzle.

3

(a)

Why the members of class-Deuteromycetes are considered the fungi imperfecti?

3

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There is a myth that immediately after heavy rains in forest, mushrooms appear in large number and make a very large ring or circle, which may be several metres in diameter. These are called 'fairy rings'. Can you explain the myth of fairy rings in biological terms?

3

(a)

Justify at what extent the phylogenetic relationship is useful as a criterion for classification.

3

(a)

The two kingdom classification system placed bacteria, algae, blue-green algae, fungi, mosses, ferns, gymnosperm, and angiosperms, together under one single kingdom-Plantae. According to you, what could have been the basis of such classification?

3

(a)

Why the vascular plants dominated land?

3

(a)

Could the number of eggs or young ones produced by an oviparous and viviparous mother be equal? Why?

3

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How many species are present in class Amphibia?Make a list of its members.What may be the reason that they are partially successful although they can also live on land?

3

(a)

Which structures form gynoecium? How is placenta related to gynoecium? What are its types?

3

(a)

Succinic dehydrogenase is an enzyme that causes the substrate, succinate, to break down into fumarate
Malonate is a substance that resembles succinate and inhibits the activity of succinic dehydrogenase
Explain how this type of inhibition affects the activity of the enzyme

3

(a)

Proteins have primary structure. If you are given a method to know which amino acid is at either of the two termini (ends) of a protein, can you connect this information to purity or homogeneity of a protein?

3

(a)

Living state and metabolisms are synonyms. Justify.

3

(a)

Enzymes are proteins. Proteins are long chains of amino acids linked to each other by peptide bonds. Amino acids have many functional groups in their structure.
These functional groups are ionizable as they are weak acids and bases in chemical nature. This ionisation is influenced by the pH of the solution. For many enzymes, activity is influenced by surrounding pH. This is depicted in the curve given explain briefly.

3

(a)

The lines A to D below show how change in temperature can affect the rate of enzyme reaction.Line N shows the rate of reaction under optimum temperature.

Which line A, B, C or D shows the rate of enzyme reaction at \(60°C\)?

3

(a)

Meiosis is advantageous than mitosis as it produces variations so plays important role in evolution. What are the stages during which chances of recombination of genes are increased during meiosis? Explain these events.

3

(a)

Well-watered plants transpire more during sunny and windy days than in cool and calm mornings. Comment.

3

(a)

Would a defoliated plant respond to photoperiodic cycle? Why?

3

(a)

What would happen if for some reason goblet cells become non-functional. Why are these important for digestive system?

3

(a)

Diffusion of gases occurs in the alveolar region only and not in the other parts of respiratory system. Why?

3

(a)

(i) Which bones of the skull are movable?
(ii) How many vertebrae are there in vertebral column?
(iii) Why is atlas vertebra called yes bone?

3

(a)