Class 12 Biology — Chapter 4: Principles of Inheritance and Variation

What you'll learn

• ▸Introduction to Heredity and Variation
• ▸Mendel's Experimental Approach
• ▸Seven Pairs of Contrasting Traits
• ▸Inheritance of One Gene (Monohybrid Cross)
• ▸Concepts of Genes and Alleles
• ▸Principle of Dominance

Chapter Summary

--- PAGE 1 --- UNIT VII GENETICS AND EVOLUTION Chapter 4 Principles of Inheritance and Variation Chapter 5 Molecular Basis of Inheritance Chapter 6 Evolution The work of Mendel and others who followed him gave us an idea of inheritance patterns. However the nature of those 'factors' which determine the phenotype was not very clear. As these 'factors' represent the genetic basis of inheritance, understanding the structure of genetic material and the structural basis of genotype and phenotype conversion became the focus of attention in biology for the next century. The entire body of molecular biology was a consequent development with major contributions from Watson, Crick, Nirenberg, Khorana, Kornbergs (father and son), Benzer, Monod, Brenner, etc. A parallel problem being tackled was the mechanism of evolution. Awareness in the areas of molecular genetics, structural biology and bio informatics have enriched our understanding of the molecular basis of evolution. In this unit the str…

Practice Questions from this Chapter

Tap "Get Solution" on any question to ask our AI tutor.

1. Explain how genes work. Get Solution →
2. Describe DNA's double helix. Get Solution →
3. Identify examples of inherited traits. Get Solution →
4. Who is credited with conducting hybridisation experiments on garden peas for seven years, leading to the laws of inheritance? Get Solution →
5. What is the biological process by which characters are passed on from parent to progeny? Get Solution →
6. What term did Mendel use for the units of inheritance that are stably passed down through generations? Get Solution →
7. In Mendelian genetics, an organism with a genotype consisting of two identical alleles, such as TT or tt, is called what? Get Solution →
8. What term describes the observable characteristics of an organism, like being 'tall' or 'dwarf'? Get Solution →

Did you know?

• 💡 One human cell holds about two meters of DNA.
• 💡 Your DNA is 99.9% identical to every other person's DNA.
• 💡 Humans share roughly 50% of their DNA with a banana.
• 💡 Gregor Mendel, the father of genetics, was an Augustinian monk.
• 💡 Some people can smell asparagus due to a specific gene.

Frequently Asked Questions

Related Chapters