The CFTR gene, on human chromosome 7, encodes an ion channel protein that regulates chloride ion concentrations. Mutations that disrupt CFTR function may lead to a disease called cystic fibrosis. How many copies of the CFTR gene are present in a cell that is... In G1 of the cell cycle
In G2 of the cell cycle
In a sperm cell
In prophase I of meiosis In a primary spermatocyte In a second polar body
In a recently fertilized zygote