Science
Heredity and Evolution
आनुवंशिकता और विकास
This Class 10 Science topic from the chapter “World of Living” explains how traits are passed from parents to offspring through genes and chromosomes. Students explore Mendel’s experiments, dominant and recessive traits, inherited variation, and the basic idea of sex determination in humans. The topic also introduces evolution, showing how variations, natural selection, fossils, and similarities or differences among organisms help us understand the gradual development of life over generations.
Practice questions
How is genetic drift different from natural selection?MediumLevel 21The idea that one form of a trait comes from each parent explains what?MediumLevel 21If the dominant form of a trait is present, what can happen to the recessive form?MediumLevel 21If a useful variation increases generation after generation in a population, what can happen over a long period?MediumLevel 21Which statement most correctly states the relation between heredity and evolution?MediumLevel 21Which option correctly connects three main ideas of this chapter?MediumLevel 21If an offspring shows both similarity to and difference from its parents, what is the most correct reason?HardLevel 19Why is it incomplete to consider a gene merely as the name of a trait?HardLevel 19Why is having half the chromosome number in gametes necessary for genetic stability?HardLevel 19If human gametes had the same chromosome number as body cells, what problem would occur in every generation?HardLevel 19What was the greatest usefulness of pea plants in Mendel's experiments?HardLevel 19In a cross between pure tall and pure dwarf plants, all first-generation plants appear tall. What does this prove?HardLevel 19The reappearance of the hidden dwarf trait in the second generation disproves which idea?HardLevel 19If a plant has one dominant and one recessive form for height, why will it appear tall?HardLevel 19Under which condition will a recessive trait appear externally?MediumLevel 19What deeper idea is shown by the 3:1 ratio in the second generation of a monohybrid cross?HardLevel 19What is the main meaning of the 9:3:3:1 result in a dihybrid cross?HardLevel 19If a person strengthens muscles through lifelong exercise, why will this change not pass directly to offspring?MediumLevel 19Why can offspring of mice still be born with tails even after tails are cut for many generations?HardLevel 19Why does natural selection depend not merely on variation but on inherited variation?HardLevel 19