Answer:Wildebeest are considered keystone species because their presence has myriad effects on the ecosystem, unlike those of any other species. Wildebeest are the "lawnmowers" of the Serengeti grassland. They keep grass short which in turn reduces the frequency of fires.
Answer:
In plant cell there present an important organelle, chloroplast that converts sunlight energy into energy during light and dark reaction.
Androgen hormone is the primary determinant of whether a baby will develop male or female external genitalia.
Androgen is usually a steroid hormone. The predominant and most active androgen in testosterone, which is produced by the male testes. Some androgens are naturally produced in the body and if the body doesn't make them properly they can be obtained through prescription medication.