Are passed from parents to offspring, determining an offspring traits

chromosomes

I got it wrong on usatestprep bc i put nuclei and it corrected me and its  

chromosomes

answer; i believe the correct answer is (anemia);

the menstrual cycle – higher tier. negative feedback mechanisms affect the production of hormones in the menstrual cycle. oestrogen also stimulates the release of lh (luteinising hormone) from the pituitary gland, which in turn controls the production of progesterone.