Q1
The process by which favourable traits become more common in a population is called:
Anatural selection
Bgenetic drift only
Cmutation only
Dcloning
CBSEClass 10 (CBSE)ScienceCh 8 · Topic 2
Evolution and Natural Selection
Learning how species change over time through natural selection.
Core concept
Evidence for evolution includes homologous organs (similar structures with a common origin but different functions across species, like a human arm and a bat's wing), fossil records showing gradual changes across geological time, and observed cases of natural selection in action, such as antibiotic-resistant bacteria evolving due to selective pressure from antibiotic use. Evolution does not mean organisms 'try' to change; rather, random genetic variations that happen to be beneficial are naturally favoured by survival and reproduction over generations.
Exam highlight
Key diagram
Keywords worth remembering
Trending
evolution and natural selectioncbse class 10
Most searched
CBSE class 10 evolution and natural selection
Quick revision
Study resources
Notes & downloads
Quick notes
• Evolution: gradual change in a species' inherited characteristics over many generations.
• Natural selection: organisms with favourable traits survive and reproduce more, passing on those traits.
• Evidence for evolution: homologous organs, fossil records, and antibiotic-resistant bacteria.
• Evolution occurs through random genetic variation naturally favoured by survival, not intentional change.