The shortest part of the cycle. Chromosomes are duplicated during this phase. Cyclin is destroyed toward the end of this phase. B. Each chromosome is made of two chromatids. The nuclear envelope reappears.
Chromosomes begin to uncoil.
The centrosome is a region in which a. chromatids are attached to one another. E. new spindle microtubules form. Both c and d are correct. Use the following key for questions 23 - 26. A couple who are both carriers for the gene for cystic fibrosis have two children who have cystic fibrosis.