The genotype is the complete genetic make up of an organism, specifically the set of genes or alleles (variant forms of a gene) it carries. It is the hereditary material passed from parents to offspring, coded in the DNA.

A. nucleotide is the basic building block (monomer) of the nucleic acids DNA and RNA, not the entire genetic makeup itself.

B. karyotype refers to the number and visual appearance of the chromosomes in the cell nucleus of an organism or species, often represented in an organized image, but not the specific genetic information or gene variants within them.

C. phenotype refers to the observable physical characteristics or traits of an organism (e.g., eye color, height), which are a result of the interaction between the genotype and environmental factors, not the genetic makeup itself.