The genetic make-up of an organism is called its __________.

• A. Phenotype
• B. Genotype
• C. Chromosome complement
• D. Chromatin

Answer: (B)

Genotype is the genetic make-up—the specific alleles and DNA sequences an organism carries. It serves as the internal blueprint that, together with environmental factors, can influence which traits are possible or likely to be expressed. This is different from the phenotype, which is the observable traits that result from gene expression and interaction with the environment. The chromosome complement refers to the number and structure of chromosomes an organism has, not the full set of genetic information, and chromatin is the DNA-histone complex involved in packaging and regulating that genetic material. So the term that best matches “genetic make-up” is genotype.