Consider statements about genetics: 1. A gene is a segment of DNA that codes for a protein. 2. Alleles are alternative forms of a gene. 3. The phenotype is the genetic makeup of an organism. Which are correct? MCQ with Answer and Explanation

A gene is a specific sequence of nucleotides in DNA that serves as the fundamental unit of heredity, typically coding for a specific protein or RNA molecule. Alleles are different versions or alternative forms of the same gene that occupy the same locus on homologous chromosomes and determine variations in a trait. The genotype is the genetic makeup of an organism, while the phenotype is the observable physical or biochemical characteristics. Thus, statements 1 and 2 are correct.