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"Migration may enhance or blurr the effects of selection". C...

"Migration may enhance or blurr the | Class 12 Biology Chapter Evolution, Evolution NCERT Solutions

Welcome to the NCERT Solutions for Class 12 Biology - Chapter Evolution. This page offers a step-by-step solution to the specific question from Exercise 0, Question 12: . With detailed answers and explanations for each chapter, students can strengthen their understanding and prepare confidently for exams. Ideal for CBSE and other board students, this resource will simplify your study experience.

Question 12:

"Migration may enhance or blurr the effects of selection". Comment.

Answer:

Migration is the movement of organisms among the subpopulations and this includes both immigration and emigration. Migration results in homogenization of allele frequencies among all the population in the absence of selection process. It enhances the gene pool of those alleles which have been selected and blur the effects of selection through the replenishment of alleles that were selected against by the nature.

The selection can amplify the effects of migration. If the selection is stronger than migration, then the differences among the population will be maintained. And, if the migration is stronger than selection then the differences among the population will be reduced. The diversity among the population of intermediate age reduces as the results of migration.

Other Questions of Chapter Evolution

Q: Try to trace the various components of human evolution (hint: brain size and function, skeletal structure, dietary preference, etc.)

How do you express the meaning of words like race, breed, cultivars or variety?

What is the most important pre-condition for adaptive radiation?

While creation and presence of variation is directionless, natural selection is directional as it is in the context of adaptation. Comment.

Why is nascent oxygen supported to be toxic to aerobic life forms?

Q: Find out from newspapers and popular science articles any new fossil discoveries or controversies about evolution.

Practise drawing various animals and plants.

Q: Attempt giving a clear definition of the term species

Q: Find out through internet and popular science articles whether animals other than man have self-consciousness.

Q: Using various resources such as your school library or the internet and discussions with your teacher, trace the evolutionary stages of any one animal say horse.

Popular questions of class 12 Biology

Q: What is spermatogenesis? Briefly describe the process of spermatogenesis.

Q: Why is reproduction essential for organisms? Answer

Q: Write a short note on
(a) Adaptations of desert plants and animals
(b) Adaptations of plants to water scarcity
(c) Behavioural adaptations in animals
(d) Importance of light to plants
(e) Effect of temperature or water scarcity and the adaptations of animals.

Q: With a neat diagram explain the 7-celled, 8-nucleate nature of the female gametophyte.

Q: What is DNA fingerprinting? Mention its application.

Q: What is oogenesis? Give a brief account of oogenesis.

Q: Describe the structure of a seminiferous tubule.

Q: What is triple fusion? Where and how does it take place? Name the nuclei involved in triple fusion.

Q: With a neat, labelled diagram, describe the parts of a typical angiosperm ovule.

Q: Explain the Law of Dominance using a monohybrid cross.

Recently Viewed Questions of Class 12 Biology

Taking examples under each category, discuss upstream and downstream processing.

Name the first transgenic cow. Which gene was introduced in this cow?

Q: Diagrammatically represent the experimental steps in cloning and expressing an human gene (say the gene for growth hormone) into a bacterium like E. coli ?

Q: Explain what is meant by biofortification.

What is the main idea behind “Joint Forest Management Concept” introduced by the Government of India?

Q: List two essential roles of ribosome during translation.

Q: If a population growing exponentially double in size in 3 years, what is the intrinsic rate of increase (r) of the population?

Which type of food would have lactic acid bacteria. Discuss their useful application.

Give the full form of ELISA. Which disease can be detected using it? Discuss the principle underlying the test.

Q: Explain briefly
(a) PCR
(b) Restriction enzymes and DNA
(c) Chitinase

Study Tips for Answering NCERT Questions:

NCERT questions are designed to test your understanding of the concepts and theories discussed in the chapter. Here are some tips to help you answer NCERT questions effectively:

Read the question carefully and focus on the core concept being asked.
Reference examples and data from the chapter when answering questions about Evolution.
Review previous year question papers to get an idea of how such questions may be framed in exams.
Practice answering questions within the time limit to improve your speed and accuracy.
Discuss your answers with your teachers or peers to get feedback and improve your understanding.

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