CBSE 2026 · Region 5 · Set 1 · Q27 · 3 marks
Explain Gause's 'Competitive Exclusion Principle' with the help of a suitable example.
Marking-scheme solution
− Gause’s competitive exclusion principle states that two closely related species competing for the same limited resources cannot co-exist indefinitely, and competitively inferior one will be eliminated eventually / If resources are limited the stronger competitor will dominate, driving the weaker one to extinction.
− Example: In some shallow American lakes visiting flamingoes and resident fishes compete for their common food i.e. zooplankton in the lake / The
Abingdon tortoise in Galapagos islands became extinct within a decade after the goats were introduced into the island probably due to the greater browsing efficiency of the goat or the feeding efficiency of one species (tortoise) is reduced by the interfering presence of the other species (goat) / any other correct example.
Organisms and PopulationsPopulationsUnderstandshort_answermedium
More from Organisms and Populations
- Study the given graphs (X) and (Y) depicting the annual variation in solar radiation on Earth from January to…2022 · asked 3×
- (i) Describe the population growth curve applicable in a population of any species in nature that has limited…2025 · asked 3×
- Read the following passage and answer the questions that follow: In nature, we rarely find isolated, single…2025 · asked 3×
- (i) Describe the Species-Area relationship as observed by Alexander von Humboldt, for a wide variety of taxa…2025 · asked 3×
- What is the carrying capacity of a species in a habitat? Explain the growth curve that takes this capacity…2026 · asked 3×
- (i) Write the observations made at the end of Connell's field experiment on barnacles on the rocky sea coasts…2022 · asked 3×
- The diagram below shows the distribution of two barnacle species, Chthamalus and Balanus on a rocky sea…2026 · asked 3×
- The graphs given below, A and B, represent population of elephants in two different National Parks (a…2022 · asked 3×
CBSE Class 12 Biology past-paper question from the 2026board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.