Study the population growth curve of three species of squirrels on an island. Red squirrels and gray squirrels have been the native species on the island for the past 1,000 years. The black squirrel is an invasive species. Invasive species aren’t native to the ecosystem. They move into an ecosystem because of natural changes or human intervention. In 2005, black squirrels entered this island. Red squirrels and black squirrels have identical food requirements, but gray squirrels eat different kinds of food. What’s the plausible reason for the population change? A. The red squirrel has no predators, and the black squirrel has many predators. B. The gray squirrel competes with the black squirrel for food. C. The black squirrel has no predators, and the red squirrel faces higher competition for resources. D. The black squirrel has many predators and faces tougher competition for resources. Reset Next

In order to understand the problems of unwanted infertility in a country — the gambia — where the desire for children and the fertility is very high, a population-based survey was undertaken. all infertile women in 24 randomly selected enumeration areas were assessed. the study included a review of the problems faced and coping mechanisms employed by infertility clients and types of health care available for infertile couples in the different types and levels of the formal and traditional health system. half of the infertile couples failed to seek formal health care, and they have to reach a certain level of care in order to be properly managed. alternative care is often sought. child fostering is also a frequent solution to childlessness. in-depth interviews revealed that traditional care like healers and spiritual leaders are frequently consulted long before formal health care. this delay could be a problem in those cases where infertility is caused by infections.