A haploid cell capable of fusion is a

• A. Diploid
• B. Gamete
• C. Chromosome
• D. Allele

Answer: (B)

In sexual reproduction, fertilization happens when two haploid reproductive cells fuse. A haploid cell capable of fusion is a gamete. Gametes are the specialized cells (like sperm and egg in humans) whose job is to join with another gamete to form a new diploid organism. The reason this is the best term is that it specifically identifies the cell type that is prepared for fusion and carries one set of chromosomes.

The other terms describe different things. A diploid refers to a cell with two full sets of chromosomes, which is what the zygote becomes after two gametes fuse; it’s not the cell that fuses. A chromosome is a single structure containing DNA, not a cell itself. An allele is a variant form of a gene, not a cell type.