Answer:
Some diseases are more common in certain groups of people, such as Caucasians or African Americans because individuals in such ethnic groups often share certain alleles (versions of their genes), that have been passed down to them from common ancestors and a particular genetic disorder may be more frequently seen in such groups if one of these shared genes contains a disease-causing mutation.
Explanation:
Some genetic diseases are frequently seen in certain ethnic groups like Caucasians or African Americans. Individuals in such groups often share certain alleles (versions of their genes), that have been passed down to them from common ancestors and one of these shared genes may contains a disease-causing mutation.
Examples of certain genetic disorders that are more common in particular ethnic groups include the Tay-Sachs disease, which is more common in people of eastern and central Europe (Ashkenazi), Jewish or French Canadian ancestry and the sickle cell disease, which occur among people of African, African American, or Mediterranean heritage.
Some genetic disorders are more common in people whose ancestry can be traced to a particular geographic area. The factors that can lead to development of populations with very different genetic allele frequencies include their geographic origin, selection, patterns of migration, historic events, etc. Certain natural barriers like oceans and other water bodies, high mountains, large deserts, or major cultural factors had prevented communication and interaction between people. So mating was restricted within the group, and this produces genetic marker differences and differences in the presence of specific disease-related alleles.
Answer: According to Darwin theory of evolution the struggle for existence is considered as major part for competition among living things.
Explanation:
Coexisting species that belong to the same genera compete for same kind of resources for their survival. Some phenotypic variations gives an survival advantage over others. The superior ones dominate the inferior ones and compete for resources. The one who receives the resources like mates, food, shelter, and others the chances of survival also increases considerably.
After the worms have finished eating their food, the students must now weigh the worms and record this data. They can then compare these new weights to the starting weights of the worms and see if it demonstrates their hypothesis. Hope this helped :)
The correct option is C.
Scanning electron microscope is a type of microscope that uses beams of electrons that are reflected to form images to scan the surfaces of mounted biological specimens. High resolution, three dimensional images can be obtained via the reflected beam of electrons. Thus, the electron scanning microscope is the perfect microscope for examining the contours on the surface of a bacterial cell.
False
<span>Marine ecosystems like lakes and oceans have aphotic zones. Aphotic zones refer to the zones in the water where there is little or no sunlight. It is found in bodies of water were depths only receive less than 1% of sunlight penetrations. Bioluminescence is essentially the only light found in this zone and most food comes from dead organisms that sink at the bottom of lakes or oceans. </span>
