_______ is useful for the survival of species over time. 

The Correct answer is Variation.

Key Points

• Variation is essential for the survival of species over time as it helps organisms adapt to changing environments.
• It occurs due to genetic differences among individuals within a species.
• Variations can arise through processes like mutation, recombination during reproduction, and environmental factors.
• These differences may provide certain individuals with a survival advantage, especially when environmental conditions change.
• This mechanism leads to natural selection, which ensures that favorable traits are passed on to future generations.
• For example, the development of antibiotic resistance in bacteria is an outcome of genetic variation and selection pressure.
• It contributes to the evolution of species, ensuring long-term survival and adaptability.
• Without variation, species would be unable to cope with new challenges like diseases, predators, or climate changes, leading to extinction.

 Additional Information

• Reproduction
  • Reproduction is the biological process by which new individual organisms are produced.
  • It ensures the continuity of species but does not directly aid in the survival of species in changing environments.
  • There are two types of reproduction: sexual reproduction (involving two parents and genetic variation) and asexual reproduction (involving one parent and no variation).
• Budding
  • Budding is a type of asexual reproduction commonly seen in organisms like yeast and hydra.
  • It involves the formation of a new organism from a small projection or bud on the parent organism.
  • Since it is a type of asexual reproduction, it does not lead to genetic variation.
• Population
  • A population refers to the group of individuals of the same species living in a particular area.
  • While the size and density of a population are important, they do not directly ensure the survival of species in changing environments.