CBSE 2022 · Region 2 · Set 1 · Q6 · 2 marks
Study the given graphs (X) and (Y) depicting the annual variation in solar radiation on Earth from January to December and answer the undermentioned questions.
(X)(Y)
(i) Identify the graph that depicts (I) tropical region, and(II)temperate region, respectively.(ii)Which of the two regions, (X) or (Y), will show high biological diversity and why ? Give two reasons.(b)When prickly pear cactus was introduced into Australia in early 1920s, it caused havoc and ecosystem instability by achieving very high population densities. Explain the reason for its rapid spread into millions of hectares of rangeland.(ii)State the importance of 'Prey-predator' relationship in a habitat.
Study the given graphs (X) and (Y) depicting the annual variation in solar radiation on Earth from January to December and answer the undermentioned questions.
(X)
(Y)
(i) Identify the graph that depicts (I) tropical region, and
(II)
temperate region, respectively.
(ii)
Which of the two regions, (X) or (Y), will show high biological diversity and why ? Give two reasons.
(b)
When prickly pear cactus was introduced into Australia in early 1920s, it caused havoc and ecosystem instability by achieving very high population densities. Explain the reason for its rapid spread into millions of hectares of rangeland.
(ii)
State the importance of 'Prey-predator' relationship in a habitat.
Marking-scheme solution
(i)
(I)
Y, (II) X
(ii)
● Y will show high biological diversity
● Reason : less seasonal / constant and predictable environment, more solar energy available for species diversification
OR(b)
(i) Does not have its natural predators.
(ii)
predators act as conduits for energy transfer across trophic levels, they keep prey population under control, predators help in maintaining species diversity in a community by reducing competition among prey species, if a predator is too efficient and over exploits its prey then the prey become extinct followed by predator / predators are prudent in nature.
Organisms and PopulationsPopulationsAnalysevery_short_answermedium
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CBSE Class 12 Biology past-paper question from the 2022board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.