Answer:
Two European men and two Polynesian women settled on a previously uninhabited tropical island. All four of the settlers have brown eyes, a dominant trait, but one of the Europeans is heterozygous and carries the recessive gene for blue eyes. No new settlers arrive,and nobody leaves the island.After a few generations,the percentage of blue-eyed individuals increases from the original zero to 25 percent.This is probably due to which of the following factors?
genetic drift
Explanation:
Genetic drift entails when there are changes in the gene frequency which occur in a gene that is existing. From the analogy above, it is a known fact that only gneetic drift could allow such to happen as mutation will only occur with a sudden change of gene which is not the case described above
Answer:
The coughing reflex kicks in, only if the epiglottis reflex fails to. If the coughing reflex fails then the Heimlich maneuver may be needed.
The ability of an organism to maintain internal conditions is called <em>C homeostasis </em>
Answer:
Enhancement in the life expectancy of humans can exhibit certain unwanted outcomes that could affect the quality of life. Some of the probable social and ecological outcomes due to an increase in life expectancy are:
Social: Greater life expectancy would signify that the age of employment would get extended. As an outcome, the older individuals would hold the seats for a longer duration, leaving only some seats for the young. This would influence the life quality and development of the young.
Due to the increase in life expectancy, there would be an elevation in the demand for basic needs, and increased consumption of food increased utilization of land, and larger population. The use of global resources would increase by humans, therefore, declining the resources at a greater rate. Hence, overall, the ratio of the old to the young would get influenced, and therefore, the quality of life would get affected.
Ecological: With longer life expectancy, there will be an enhanced burden of human species on the planet Earth. Due to this, the balance between the humans and the other species would get disturbed. Human activities have been substantially related to the issues of global warming, issues of deforestation, endangering of other species resulting in ecological imbalance.
Enhancement in the life expectancy of humans would cause further destruction of endangered species and huge imbalance in the ecosystems that would eventually influence life of human beings. Therefore, ecological in combination with socioeconomic influence of greater life expectancy incline towards reduced quality of life, and it is not desirable.
Every protein has in itself molecular parts that function like zip codes and are used to designate where the protein must travel.