What are alternative forms of a gene called?

Alternative forms of a gene are called alleles. Alleles represent variations in the DNA sequence at a particular gene locus, which can lead to different traits or characteristics being expressed. For example, a gene that determines flower color may have one allele for red flowers and another for white flowers.

Each individual receives one allele from each parent, and the combination of these alleles determines the organism's traits. This genetic variation is crucial for evolution and helps populations adapt over time. Recognizing the role of alleles is essential in understanding inheritance patterns and the molecular basis of traits that can be observed in phenotypes.

The other options do not accurately describe alternative forms of a gene. Chromatids are strands of replicated chromosomes, genomes refer to the complete set of genes within an organism, and phenotypes describe the observable characteristics resulting from the genotype and environmental interactions.