Ateam of scientists visits an island in the caribbean sea. they find a diverse community of turtles, lizards, birds, and a variety of trees, shrubs, and grasses. no humans live on the island. several years later, the scientists return to the island. they find a much smaller community, with reduced populations of all of the species they had identified earlier. some of the animals now appear to be absent from the island. which is the most likely explanation for the changes that the scientists observed? a. competition for resources caused all of the island populations to decrease at the same time. b. a disease or parasite affected all of the island populations. c. a natural disaster, such as a hurricane, struck the island. d. stress from overcrowding affected all of the island populations.

C. A natural disaster, such as a hurricane, struck the island.

A limiting factor is a resource or ecological condition because of which growth and distribution of an organism or group of organisms living in an ecosystem limits. A limiting factor can be of either physical or biological in nature. A limiting factor restricts organisms from occupying their fundamental niche. Examples of limiting factor are resources, stress due to overcrowding, disease or parasite and a natural disaster. According to the condition mentioned natural hazard can be the only limiting factor to limit the population at such considerable rate. Natural disaster is a physical limiting factor which has catastrophic impact of populations of different species living in an ecosystem. It has the potential to wipe out several inhabitants in one drastic event. Therefore, a natural disaster, such as a hurricane, struck the island can be a most likely explanation for the changes that the scientists observed.  

the corpus luteum secretes estrogens and progesterone. the latter hormone causes changes in the uterus that make it more suitable for implantation of the fertilized ovum and the nourishment of the embryo. if the egg is not fertilized, the corpus luteum becomes inactive after 10–14 days, and menstruation occurs.

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