Answer:
When there is a mistake in the copying of the genetic message that is permanent, a mutation has occurred. Two of the bases in DNA (Cytosine and Thymine) are the most vulnerable, and when this happens, they may pair with each other or themselves and the message is changed.
Explanation:
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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.
Rough Endoplasmic Reticulum: series of connected flattened sacs, part of a continuous membrane organelle within the cytoplasm of eukaryotic cells, that plays a central role in the synthesis of proteins.
Smooth Endoplasmic Reticulum: comprises of a tube-like structure located near the cell periphery. These tubules or tubes sometimes branch forming a network that is reticular in appearance. The network of smooth endoplasmic reticulum allows for an increased surface area to be devoted to storage of key enzymes.
Answer:
animals that eat only plants.
<u>Answer</u>: Natural selection.
<u>Explanation</u>:
- The concept of <em>natural selection</em> was given by <em>Charles Darwin.</em>
- According to this concept, in a given environment the organisms that possess <em>better adaptations</em> have<em> higher chances of survival</em> and, leave behind a <em>greater number of progenies</em>.
- When malaria outbreak occurs, the allele frequencies change and only the organisms that possess the alleles which help them to <em>survive</em> this outbreak due to resistance against malarial infection will be selected by nature and<em> hence, this is an example of natural selection.</em>
