Gonads are the body structures that produce sex cells. Sperm are the male sex cells. Eggs are the female sex cells. Chromatin are threadlike DNA found inside the sex cells.
I think it is stage 2
At stage two, the skin breaks open, wears away, or forms an ulcer, which is usually tender and painful. The sore expands into deeper layers of the skin. It may appear as a scrape, blister, or a shallow crater in the skin. At times this stage looks like a blister filled with clear liquid. Also at this stage some skin may be damaged beyond repair or may die.