A genetic study was conducted on a strain of C. elegans that is heterozygous for a gene essential for development. The following observations were made from the progeny resulting from a cross between heterozygous individuals:
- PCR analysis of genomic DNA from the progeny revealed that 50% of the individuals lacked the essential gene.
- Northern blot analysis showed the presence of the gene's transcript in all individuals, including those lacking the gene.
- No developmental lethality was observed in any of the progeny.
Which one of the following options best explains these observations?
1
The gene's function is compensated by a duplicated gene.
2
The transcripts are maternally contributed.
3
The gene's product is provided by the diet of the worms.
4
The gene is expressed from an extrachromosomal element.