Correct Option
The correct option is 1 and 3 only.
Explanation
Biodiversity is measured at three levels: genetic, species, and ecosystem. Genetic diversity refers to the total number of genetic characteristics in the genetic makeup of a species. It represents the variation of genes within a single species.
Statement 1 is Correct:
Genetic diversity is explicitly defined as the variation of genes within a particular species. It encompasses the genetic differences between individuals of the same species (e.g., different breeds of dogs or varieties of rice).
Statement 2 is Incorrect:
Genes are the fundamental units of heredity that determine the physical and physiological traits (phenotypes) of an organism. Genetic diversity directly influences physical characteristics such as size, color, shape, and resistance to diseases. For example, the variation in human eye color or height is a result of genetic diversity.
Statement 3 is Correct:
High genetic diversity is crucial for the healthy breeding and long-term survival of a population. It ensures that the population has a wider gene pool, which facilitates adaptation to changing environmental conditions and provides resilience against diseases. Low genetic diversity can lead to inbreeding depression, where offspring are more susceptible to genetic defects and environmental stress.
Key Takeaway:
Genetic diversity operates at the intra-species level (within a species) and is vital for natural selection, adaptation, and the prevention of inbreeding depression.