Final answer:
Major effects of endocrine disruptors in females include disrupted menstrual cycles and potential reproductive health issues, including mimicking hormones like estrogen and leading to altered gene expression.
Step-by-step explanation:
The major effects of endocrine disruptors in females include disrupted menstrual cycles and potential reproductive health issues. Endocrine disruptors are chemicals that interfere with the hormonal system, which can lead to numerous health problems. For instance, they can mimic hormones like estrogen and may lead to altered gene expression even at low doses. This disruption can have severe consequences including disruptions in sexual development, fertility issues, and increased risk of certain types of cancer such as breast cancer.
Studies have shown that endocrine disruptors can cause various adverse effects. For example, the chemical bisphenol A (BPA) can be found in many plastics and can mimic estrogen in the body. In one experimental study, the introduction of ethynylestradiol, an ingredient in birth control pills, into a lake affected the sexual development of fish, leading to population collapse over time. This highlights the potential long-term effects of such chemicals on both individual organisms and entire populations.
Therefore, the correct answer to the student's question would be b. Disrupted menstrual cycle, as the endocrine disruptors can lead to a range of detrimental effects on female reproductive health, rather than improving it, enhancing hormones production uniformly, or reducing cancer risks.