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Welcome to the NCERT Exemplar Solutions for Class 12 Biology Chapter 5 – Principles of Inheritance and Variation. These solutions have been carefully crafted by subject specialists at Infinity Learn. They provide thorough answers to all the unsolved questions from the textbook’s exercises, making them a valuable resource for improving your conceptual knowledge in Class 12 biology chapter 5.
These solutions are designed to be easy to understand, using simple language that students can relate to. They follow the norms required for solving NCERT Exemplar Solutions for Class 12 biology chapter 5, ensuring that you get the right answers. Practicing these solutions can significantly help you perform well in exams like JEE mains Exam and NEET Exam, as they cover the important questions and topics from class 12 biology chapter 5.
NCERT solutions are structured to help you stay focused and answer questions efficiently. Time management is crucial in exams, and these solutions for class 12 biology chapter 5 question answer are designed to help you manage your time effectively to achieve the best results.
NCERT Exemplar Class 12 Biology Chapter 5 – Principles of Inheritance and Variation PDF
Prepare for your Class 12 biology exams with the NCERT Exemplar for Chapter 5: Principles of Inheritance and Variation. This PDF contains detailed solutions to all the questions from the textbook exercises. Practicing these solutions will help you understand the key concepts better and score high marks in your exams.
The content aligns with the Class 12 biology Syllabus, making it a valuable resource for your preparation. Download the NCERT Exemplar Class 12 Biology Chapter 5 – Principles of Inheritance and Variation PDF now and start your journey towards success in biology!
NCERT Exemplar Class 12 Biology Chapter 5 – Principles of Inheritance and Variation Questions and Answers
Ques: What is the principle of segregation?
Ans: The principle of segregation states that during the formation of gametes, the two alleles for a gene separate, so that each gamete carries only one allele for each gene. This was first proposed by Gregor Mendel based on his experiments with pea plants.
Ques: Explain the concept of independent assortment.
Ans: The principle of independent assortment states that genes for different traits can segregate independently during the formation of gametes. This means the distribution of alleles for one trait does not affect the distribution of alleles for another trait. This principle was also discovered by Gregor Mendel.
Ques: What is a test cross and why is it used?
Ans A test cross involves breeding an individual with a dominant phenotype (but unknown genotype) with a homozygous recessive individual. This helps to determine the genotype of the dominant individual. If the dominant individual is homozygous, all offspring will show the dominant trait; if heterozygous, approximately half of the offspring will show the recessive trait.
Ques: Define codominance and give an example.
Ans: Codominance occurs when both alleles in a heterozygous individual are fully expressed, resulting in a phenotype that shows both traits equally. An example of codominance is the AB blood group in humans, where both A and B alleles are expressed.
Ques: What is incomplete dominance? Provide an example.
Ans: Incomplete dominance is a form of inheritance where the heterozygous phenotype is intermediate between the two homozygous phenotypes. An example is the flower color in snapdragons, where crossing a red-flowered plant with a white-flowered plant produces offspring with pink flowers.
Ques: Describe the significance of linkage and recombination in genetics.
Ans: Linkage refers to the tendency of genes located close to each other on the same chromosome to be inherited together. Recombination (or crossing over) is the process by which homologous chromosomes exchange genetic material during meiosis, leading to new combinations of alleles. Linkage reduces genetic variation, while recombination increases it.
Ques: What is a pedigree chart and how is it used in human genetics?
Ans: A pedigree chart is a diagram that shows the occurrence of a genetic trait in several generations of a family. It is used to analyze the pattern of inheritance of specific traits, to predict the probability of genetic disorders in future offspring, and to identify carriers of recessive alleles.
Ques: Explain the concept of multiple alleles with an example.
Ans: Multiple alleles refer to the existence of more than two alleles for a genetic trait within a population. An example is the ABO blood group system in humans, where the gene for blood type exists in three allelic forms: I^A, I^B, and i.
Ques: What are polygenic traits? Give an example.
Ans: Polygenic traits are controlled by two or more genes, each contributing to the phenotype in a cumulative or additive manner. An example is human skin color, which is influenced by several genes.
Ques: Differentiate between epistasis and pleiotropy.
Ans: Epistasis occurs when the expression of one gene is affected by another gene, often masking or modifying its effects. Pleiotropy refers to a single gene influencing multiple phenotypic traits. For example, the gene responsible for Marfan syndrome affects connective tissue, impacting the skeleton, eyes, and cardiovascular system.
Ques: What is a monohybrid cross? Provide an example.
Ans: A monohybrid cross involves a single pair of contrasting traits and examines the inheritance of these traits over one generation. An example is Mendel’s cross between tall (TT) and dwarf (tt) pea plants, resulting in all tall (Tt) offspring in the F1 generation.
Ques: Describe the phenomenon of genetic drift.
Ans: Genetic drift is a random change in allele frequencies in a population, often having a more significant effect in small populations. It can lead to the loss of genetic diversity and even cause certain alleles to become fixed or lost entirely.
Ques: Explain the significance of Hardy-Weinberg equilibrium.
Ans: The Hardy-Weinberg equilibrium describes a theoretical state in which allele frequencies in a population remain constant over generations in the absence of evolutionary influences. It provides a baseline for detecting evolutionary changes and understanding genetic variation within populations.
Ques: What is the difference between autosomal and sex-linked inheritance?
Ans: Autosomal inheritance involves genes located on the autosomes (non-sex chromosomes), affecting both sexes equally. Sex-linked inheritance involves genes located on sex chromosomes (X or Y), often resulting in traits that predominantly affect one sex. For example, hemophilia is an X-linked recessive disorder.
Ques: Describe the process of crossing over and its significance.
Ans: Crossing over is the exchange of genetic material between homologous chromosomes during prophase I of meiosis. It results in new combinations of alleles, increasing genetic diversity and contributing to variation in offspring.
Introduction to Chapter 5: Principles of Inheritance and Variation
This chapter is part of the Unit on Genetics and Evolution, which is crucial for understanding the principles of inheritance and variation. According to recent trends, this Unit accounts for approximately 18 marks, making up about 25% of the questions in the exam paper.
To perform well in your exams, it’s essential to practice all the questions and understand the concepts from all the chapters under this Unit. Studying the principles of inheritance and variation helps you understand the process of evolution and explains the differences in characteristics among species.
Key concepts covered in this chapter include:
- Mendel’s Laws of Inheritance
- Inheritance of One Gene
- Inheritance of Two Genes
- Sex Determination
- Mutation
- Genetic Disorders
Key Features of NCERT Exemplar Solutions for Chapter 5 from Class 12
- The content is designed to be simple and easy to understand.
- The answers are provided by subject experts.
- Practicing these solutions improves your conceptual knowledge.
- NCERT Exemplar Solutions are also useful for competitive exams.
- Well-labeled diagrams are used wherever necessary.
- The solutions are created keeping in mind the Term I CBSE Syllabus.
NCERT Exemplar Solutions for Class 12 Biology Chapter 5 FAQs
What is the purpose of the NCERT Exemplar Solutions for Class 12 Biology Chapter 5?
NCERT Exemplar Solutions provide detailed, step-by-step answers to all the unsolved questions from the textbook exercises for Chapter 5. They are designed to help students improve their conceptual understanding and prepare effectively for exams and competitive tests.
How do the NCERT Exemplar Solutions differ from the textbook solutions?
The Exemplar Solutions go beyond just providing answers - they explain the concepts and problem-solving approaches in student-friendly language. The solutions adhere to the format and norms required for NCERT Exemplar questions, making them a reliable resource.
Who creates the NCERT Exemplar Solutions for Class 12 Biology Chapter 5?
The NCERT Exemplar Solutions are created by subject matter experts at Infinity Learn. They ensure the solutions are accurate, comprehensive, and aligned with the latest CBSE curriculum and examination patterns.
The NCERT Exemplar Solutions are created by subject matter experts at Infinity Learn. They ensure the solutions are accurate, comprehensive, and aligned with the latest CBSE curriculum and examination patterns.
Practicing the Exemplar Solutions can help students strengthen their grasp of concepts, develop problem-solving skills, and improve their performance in exams like JEE Mains and NEET. The solutions also provide valuable insights into the types of questions that can be asked.
