The correct answer is (1) More than two sets of chromosomes, both of which are from the same parental species.

Concept: what is autopolyploidy?

Autopolyploidy means an organism has more than two complete sets of chromosomes, and all these sets originated from the same species (usually by genome duplication or unreduced gametes). Typical examples are autotetraploids (4x) or autotriploids (3x) in which every set is just another copy of the same basic genome.

Option‑wise explanation

1. More than two sets of chromosomes, both of which are from the same parental species – correct

   • This directly captures the definition: polyploidy (>2 sets) and all sets derived from one species.

   • Autotriploid (AAA) or autotetraploid (AAAA) genomes fit here.

2. More than two sets of chromosomes, both of which are from the different parental species – allopolyploidy, not auto

   • When extra sets come from different species (e.g., AABB, AABBDD), the condition is allopolyploidy.

   • This describes bread wheat type situations, not autopolyploids.

3. More than two sets of chromosomes only from a single parent

   • Ambiguous and misleading: sounds like uniparental inheritance, not necessarily genome duplication in a species.

   • Autopolyploidy is defined at the species level (same species genome), not “one parent” in a cross.

4. Duplication of a chromosomal locus leading to increased gene copy number

   • This is segmental duplication / copy‑number variation, not whole‑genome polyploidy.

   • Polyploidy requires duplication of entire chromosome sets, not just one locus.

Therefore, the condition that correctly represents autopolyploidy is option (1).