The access is most heavily limited by Climate
In an extremely dry and hot climates such as desert, it will be incredibly hard to access potable water because they evaporate really quickly
Meanwhile in a wet and cool climates such as rain forest, it will be extremely easy to access potable water
The Major function of the respiratory system is to exchange oxygen and carbon dioxide. Inhaled oxygen enters the lungs and reaches the alveoli, the layers of the cells lining the alveoli and the surrounding capillaries are each only one cell thick and are in very close contact with each other, the barrier between air and blood averages about 1 micron in thickness. Oxygen diffuses quickly through the air-blood barrier into the blood in the capillaries. Similarly, carbon dioxide passes from the blood into the alveoli and is then exhaled.
Cell walls are thicker than cell membranes, and can therefore support the cell well. They keep a strong boundary for the protection of the cell, but can let water and some nutrients through to nourish and power the cell. Hope this helps! :)
Answer: Promoter
Explanation:
Transcription is the first step in gene expression which consists of copying the DNA sequence of a gene to produce a RNA molecule. There are enzymes called <u>RNA polymerases which perform this process of transcription</u>. These enzymes bind nucleotides (the monomers which are part of the nucleic acids) to create a RNA strand using a DNA strand as a mold.
A promoter is a region of DNA that controls the initiation of transcription of a given portion of DNA to RNA. Therefore they promote the transcription of a gene. <u>The promoter region is composed of a specific sequence of DNA located just where the starting point of the DNA transcription is</u> and contains the information needed to activate or deactivate the gene it regulates. <u>The promoter has a binding site for the RNA polymerase enzyme </u>in charge of mRNA synthesis and when it recognizes this site, transcription begins.
