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
Why can a tall-appearing pea plant not always be considered pure tall?HardLevel 20In a dihybrid cross, what idea is supported by the 9:3:3:1 result?HardLevel 20If information for a trait does not reach reproductive cells why will the trait not pass to the next generation?MediumLevel 20Why are strong muscles developed by exercise not directly passed to offspring?MediumLevel 20Why do offspring of a mouse still have tails even after the mouse tail is cut?EasyLevel 20What is the deeper reason for increased variation in offspring during sexual reproduction?MediumLevel 20How can offspring in asexual reproduction be slightly different even though they are very similar?MediumLevel 20If reproductive cells did not have half the chromosome number what problem would occur in every generation?MediumLevel 20If a child has XY chromosomes how must this combination have formed?EasyLevel 20If daughters are repeatedly born in a family what would be scientifically wrong to blame?MediumLevel 20If a population has a useful heritable variation what is more likely during natural selection?HardLevel 20In which situation will the effect of natural selection be most clearly seen?MediumLevel 20Why can genetic drift be more effective in small isolated groups?HardLevel 20What is the main difference between natural selection and genetic drift?HardLevel 20If two populations remain separated for a long time and do not interbreed, what result is possible?HardLevel 20Why is geographical isolation more effective in speciation when the time period is long?HardLevel 20Two groups look externally similar but cannot breed successfully with each other. What can this indicate?HardLevel 20What can be understood by comparing fossils in deeper and upper layers?MediumLevel 20Why are fossils evidence of evolution but not the full story alone?MediumLevel 20What does similar structure but different function in homologous organs indicate?HardLevel 20