• Suppressor Mutations:
• Suppressor Mutation: A second mutation occurring at a distinct site from the primary mutation that partially or completely reverses or compensates for the mutant phenotypic effect, restoring the wild-type phenotype:
• Intragenic Suppressor: Occurs within the same gene (compensatory frameshift or secondary structure restoration).
• Intergenic / Extragenic Suppressor: Occurs in an entirely different gene (e.g., mutant tRNA reading through a nonsense codon).
• Correct Option: Option 3 (suppressor mutation).

• Mosaicism in Transgenic Animals:
• In genetic engineering and fish transgenesis (e.g., microinjection of recombinant growth hormone constructs into fertilized teleost eggs):
• Injected DNA construct rarely integrates prior to the first mitotic cleavage, integrating instead into one of multiple blastomeres during the $2-$, $4-$, or $8-$cell stages.
• The resulting founder ($G_0$) animals consist of a patchwork of genetically distinct cells (some with the transgene, some without), a state known as mosaicism.
• Correct Option: Option 3 (transgenesis).

• Aneuploidy Terminology:
• Aneuploidy involves the loss or gain of one or more individual chromosomes from the normal diploid set ($2n$):
• Nullisomy ($2n - 2$): Loss of both members of an entire homologous pair of chromosomes.
• Monosomy ($2n - 1$): Loss of a single individual chromosome.
• Trisomy ($2n + 1$): Addition of a single extra chromosome.
• Tetrasomy ($2n + 2$): Addition of an extra pair of homologous chromosomes.
• nalysis:
• (2n-2): Correct formula for nullisomy.
• (2n+1): Represents trisomy.

Correct option: (2) 2n-2

• Mutator Genes:
• mutator gene (or mutator locus) is a gene that, when mutated or altered, substantially increases the spontaneous mutation frequency of other loci across the genome.
• Mutator genes typically encode components of DNA proofreading, replication fidelity, and DNA repair pathways (e.g., DNA mismatch repair enzymes like MutS, MutL, MutH, or DNA polymerase error-correcting subunits).
• Defects in these genes compromise the cell's ability to correct replication errors, elevating mutation rates by $10^2$ to $10^4$ fold.
• nalysis:
• (Mutators): Correct.
• (Mutants): Organisms or alleles that have undergone mutation.
• (Mutagens): Physical or chemical agents that induce mutations.
• (Tautomers): Structural isomers that interconvert via proton shift.

Correct option: (4) Mutators