Final answer:
Humans have 23 pairs of chromosomes in their karyotype, comprising 22 pairs of autosomes and 1 pair of sex chromosomes (XX for females, XY for males), making option 3) the correct answer.
Step-by-step explanation:
Humans display 23 pairs of chromosomes in their karyotype. This includes 22 pairs of autosomes and 1 pair of sex chromosomes. Females typically have two X chromosomes (XX), while males have one X and one Y chromosome (XY). Therefore, the correct answer to the question is 3) 23 pairs.
The visualization of these chromosomes is known as a karyotype, which is an organized profile of an individual's chromosomes. In a karyotype, chromosomes are lined up by size and numbered from the longest to the shortest. The first 22 pairs are autosomal chromosomes, and the 23rd pair consists of the sex chromosomes. These chromosomes contain between 20,000 to 22,000 genes with varying alleles, making up a person's genetic makeup or genotype. The expression of these genes contributes to an individual's phenotype, which includes physical, behavioral, and biochemical characteristics.