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Speciation - Types and Factors - Unsolved Practice Set

Class 12

Chapter: Evolution | Topic: Speciation Types and Factors

Study Material.
Class 12

SPECIATION - TYPES AND FACTORS - UNSOLVED PRACTICE SET

Topic: Speciation Types and Factors

Time: 30 mins | Marks: 30 | Difficulty: Medium

Multiple Choice Questions

Q1. Speciation refers to the process by which:

  1. Individuals within a species change their behaviour
  2. New species arise from existing ones over evolutionary time
  3. A single organism changes its own genetic makeup during its lifetime
  4. Species become extinct

Q2. Speciation that occurs due to the physical separation of populations by a geographic barrier (such as a mountain range or river) is called:

  1. Sympatric speciation
  2. Allopatric speciation
  3. Parapatric speciation
  4. Artificial speciation

Q3. Speciation that occurs without any geographic separation, within the same habitat, is called:

  1. Allopatric speciation
  2. Sympatric speciation
  3. Genetic drift
  4. Gene flow

Q4. Barriers that prevent successful mating or fertilisation between different species, occurring before zygote formation, are called:

  1. Post-zygotic barriers
  2. Pre-zygotic barriers
  3. Genetic barriers
  4. Ecological barriers

Q5. Which of the following is a key factor that promotes speciation by reducing gene flow between populations?

  1. Random mating within a single large population
  2. Reproductive or geographic isolation between populations
  3. Constant migration between populations
  4. Absence of any genetic variation

Short Answer Questions

Q6. Define speciation, in your own words.

Q7. Differentiate between allopatric and sympatric speciation.

Q8. What are reproductive isolating mechanisms? Give one example of a pre-zygotic barrier.

Q9. Why is geographic isolation often considered an important trigger for allopatric speciation?

Long Answer Questions

Q10. Explain the process of allopatric speciation, describing how geographic isolation can eventually lead to the formation of new species.

Q11. Discuss the various factors, such as isolation, genetic drift, and natural selection, that contribute to speciation in natural populations.

APPLICATION / ANALYSIS

Q12. A river changes course and splits a single population of squirrels into two separate groups that can no longer interbreed. Over thousands of years, the two groups accumulate different mutations and adaptations. Using your understanding of speciation, predict what is likely to happen if the two squirrel populations were later reunited, and explain your reasoning.

Q13. Two closely related plant species grow in the same geographic area but flower at completely different times of the year, preventing cross-pollination between them. Identify the type of reproductive barrier this represents, and explain how it could have contributed to their speciation despite living in the same location.


Total: 30 Marks | Time: 30 mins

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