Which of the following steps happens first during transcription?
a. rna polymerase reaches the end of the gene.
b. rna polymerase reaches the beginning of a gene.
c. rna polymerase pulls apart the double helix.
d. rna polymerase produces mrna from dna.

The correct answer is -

B. RNA polymerase reaches the beginning of a gene.

Explanation:

Transcription is a phenomenon of synthesis of mRNA (messenger RNA) using a template DNA, which takes place with the help of enzyme RNA polymerase.

This enzyme reaches the site from where the gene begins and thus follows its transcription using a DNA template.

It adds nucleotides in the direction 5' to 3' that is complementary to the DNA template.

Therefore, to begin the process, enzyme RNA polymerase reaches the start site of gene.

Thus, option B) is the right answer.

americans began to notice growing differences between the northern and southern sections of the country. there were more people living in cities in the north, which made it more urban. more people lived on farms in the south, which made it more rural. while many people were farmers in the northern states, there were now other ways to make a living, such as working in mechanical cotton gins factories manufacturing cloth, tools and other goods. people in the north supported high tariffs on goods imported from europe because the extra cost encouraged people to “buy american” instead. in the southern states, planters did not like tariffs because they sold most of their production to europe and bought their tools from there as well. southerners believed the protective tariff was something that only northern factory owners keep their profits high. so the southern politicians came up with an idea. they would opt out. they would simply ignore the protective tariff. it was ‘null and void’ in south carolina. the state would not collect the taxes on goods imported into south carolina, no matter what the president said they had to do. this decision led to the nullification crisis.

4.) metal

"-the movement of carbon from the nonliving environment into living things and back to the environment

-carbon is the essential component of proteins, fats, and carbohydrates (which make up all organisms)

-carbon exists in air, water, and living organisms

-producers convert carbon dioxide in the atmosphere into carbohydrates during photosynthesis

-bacteria in the atmosphere cycles through the system in filtration units

-in cellular respiration, carbon is released back into the atmosphere as carbon dioxide

-some carbon is stored in limestone (forming one of the largest "carbon sinks" on earth)

-largest carbon reservoir on earth= limestone

-carbon stored in the bodies of organisms as fat, oils, or other molecules may be released into the soil or air when the organism dies

-this may form deposits of coal, oil, or natural gas (fossil fuels, which increased the atmospheric carbon dioxide)

-fossil fuels store carbon left over from bodies of organisms that died millions of years ago

-they are located in the surface of earth, deep within the earth and beneath the ocean floor."