Jeff is writing a term paper on the role of melatonin. he decides to emphasize the important role that this hormone plays in regards to

The melatonin is a hormone responsible for the regulation of the sleep cycles. this hormone is secreted by the pineal glands.

The amount of the melatonin helps the body to regulate the sleeping pattern. The levels of the melatonin is higher at night and it promotes sleeping. During daytime the level of melatonin is comparatively low.

So, the correct answer is sleeping cycle.

both male and female gametes are produced by meiosis of the germ cells. therefore, both male and female gametes are haploid. one male and one female gamete unite during the fertilization to form the diploid zygote. in seed bearing plants, pollen grain is the male gametophyte, which produces sperm cells.

the food storage products of chrysophytes are oils or the polysaccharide laminarin.   formerly classified as plants, the chrysophytes contain the photosynthetic pigments chlorophyll a and c all but the yellow-green algae also contain the carotenoid pigment fucoxanthin.