104. A haploid sperm from one species and a haploid egg from another species may form a diploid
interspecies hybrid. Meiosis in these plants generally fails but can also lead to rare duplicated
gametes called:
A. Allopolyploid
B. Aneuploid
C. Autopolyploid
D. Heteroployploid

Detailed Explanation:

In plant genetics, interspecies hybridization occurs when a haploid sperm from one species fertilizes a haploid egg from another species, producing a diploid hybrid. While this hybrid is diploid, its chromosome sets are not homologous, because they originate from two different species. This leads to complications during meiosis, often resulting in sterility because chromosomes fail to pair properly.

What happens in rare cases?

In some rare events, these plants can undergo genome duplication through abnormal meiosis or somatic doubling. This process creates duplicated gametes that are fertile, because each chromosome now has a homologous partner.

This condition leads to:

• Allopolyploidy: A condition where an organism possesses two or more sets of chromosomes derived from different species. It results from combining and doubling the genomes of distinct species, often stabilizing the hybrid and making it fertile.

Option Breakdown:

• A. Allopolyploid:
  Correct — This is the term for hybrids with chromosome sets from two different species that have undergone duplication.

• B. Aneuploid:
   Incorrect — Refers to organisms with an abnormal number of chromosomes (e.g., missing or extra chromosomes), not necessarily due to interspecies hybridization.

• C. Autopolyploid:
   Incorrect — Refers to polyploids with multiple chromosome sets from the same species, not different ones.

• D. Heteroployploid:
   Incorrect — Not a standard term used in plant genetics.

Correct Answer:

A. Allopolyploid

Allopolyploid formation is a key mechanism in plant evolution, allowing sterile hybrids to become fertile and giving rise to new species