Outline what progesterone does in the human menstrual cycle.
With reference to Table 4.1, suggest what the results of this investigation imply and explain how effective the HDR strategy is.
An investigation was carried out to find the effect of the diet of pregnant female rats on the mean age at onset of puberty in their female offspring. The pregnant female rats were given either a high fat diet or a normal diet. Their offspring were also given either a high fat diet or a normal diet. The percentage of offspring that had reached puberty was recorded at intervals until the offspring were 39 days old. The results are shown in Fig. 5.1.
State the age at which 50% of the offspring had reached puberty when both the mother and her offspring were on a normal diet.
During the 20th century, the mean age at onset of puberty in European girls fell from about 17 years to about 12 years of age. It has been suggested that moving to a richer diet was mainly responsible for this decrease. With reference to the data in Fig. 5.1, Discuss the evidence that changes in diet may be responsible for this decrease in the age of onset of puberty in European girls.