Answer:
<u>A portion of the DNA unwinds and RNA polymerase attaches to the DNA within the transcription bubble.</u>
Explanation:
Transcription is the process in which DNA template is used to synthesize mRNA.
There are three steps of transcription:
It is the process in which a portion of DNA unwinds and RNA polymerase binds to the promotor region on the DNA.
It is the process in which RNA polymerase moves along the DNA template and synthesizes mRNA. During this process, unwinding of double stranded DNA takes place.
As the RNA polymerase moves along the DNA template, it finally reaches a termination signal and then stops synthesizing. It is followed by the detachment of the newly formed mRNA and RNA polymerase from the DNA.
<u>QUESTION:</u>
- <u> A ribosome attaches to the initiation codon of a completed mRNA strand.</u>
This is the incorrect answer choice as this process does not happen in the process of transcription. This event happens<u> in the process of translation in which mRNA is used to synthesize proteins or amino acids. mRNA attaches to ribosome during this process.</u>
- <u>RNA polymerase moves along the template strand of the DNA creating an mRNA strand.</u>
This is the incorrect answer choice as this event takes place in the process of elongation.
- <u>A portion of the DNA unwinds and RNA polymerase attaches to the DNA within the transcription bubble.</u>
This is the<u> correct answer choice as this event takes place in the process of initiation of transcription</u>
- <u>The mRNA detaches from the RNA polymerase as the RNA polymerase leaves the DNA strand.</u>
This is the incorrect answer choice. This event takes place in the event of termination of transcription.
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.
4.6 billion years ago the earth formed
<span>Nucleus is the central organelle of the cell which encloses the DNA. Apart from the nucleus, there are few other organelles which have their own DNA.Mitochondria,power house of the cell has its own DNA.so the selected cell possess is mitochondria and chloroplasts.</span>
