The correct option is A.
Explanation
The question pertains to the fundamental principles of genetics and biological classification (Taxonomy) as applied to human beings.
- Statement 1 is Incorrect: While genes are indeed the functional units of heredity that carry genetic information, they are not the "basic building blocks" of life forms. In biological hierarchy, the cell is defined as the basic structural and functional building block of all living organisms. Genes are molecular sequences of DNA located within the chromosomes of a cell.
- Statement 2 is Correct: Genes are the fundamental units of heredity. They consist of specific sequences of nucleotides that act as instructions to produce molecules, usually proteins, which determine the traits and characteristics passed from parents to offspring.
- Statement 3 is Incorrect: Human beings are genetically and taxonomically classified under the genus Homo (specifically the species Homo sapiens). The genus Pan refers to chimpanzees and bonobos, which are the closest living relatives to humans but belong to a distinct taxonomic group.
Key Takeaway: The cell is the structural unit of life, whereas the gene is the functional unit of heredity; humans belong to the genus Homo, not Pan.