Final answer:
Human cells have 46 chromosomes arranged in 23 pairs. All pairs of human cells are functional, containing between 20,000 and 25,000 functional genes.
Step-by-step explanation:
How many chromosomes are functional in IGHC? This question seems to refer to the immunoglobulin heavy constant (IGHC) region, which is a part of the genetic structure within the human genome. In humans, each somatic cell contains a total of 46 chromosomes, arranged in 23 pairs. Among these, 22 pairs are autosomes and the remaining pair consists of the sex chromosomes:
two X chromosomes in females and one X and one Y chromosome in males. Each of these chromosomes carries hundreds to thousands of genes. Given that human DNA has between 20,000 and 25,000 functional genes, the chromosomes that include the IGHC genes are certainly functional.
Genes related to the IGHC can be found on chromosome 14 (14q32.33), where they encode for the constant region of immunoglobulin heavy chains. Yet, this does not mean that there is a specific number of 'functional' chromosomes for IGHC, as functionality is a property of genes, not chromosomes.