There are number of endemic species, because island isolation promotes allopatric speciation and the latter occurs when species become separated from each other to the level that prevents genetic recombination.
Answer:
The Sun's rays warm our world, stir air and ocean currents, and catalyze chemical reactions in the atmosphere. The Sun-warmed surface evaporates water to form rain clouds that redistribute fresh water around the world. And sunlight is essential for most life forms that live at Earth's surface.
Explanation:
Answer:
Explanation:
The genes in DNA encode protein molecules, which are the "workhorses" of the cell, carrying out all the functions necessary for life. For example, enzymes, including those that metabolize nutrients and synthesize new cellular constituents, as well as DNA polymerases and other enzymes that make copies of DNA during cell division, are all proteins.
In the simplest sense, expressing a gene means manufacturing its corresponding protein, and this multilayered process has two major steps. In the first step, the information in DNA is transferred to a messenger RNA (mRNA) molecule by way of a process called transcription. During transcription, the DNA of a gene serves as a template for complementary base-pairing, and an enzyme called RNA polymerase II catalyzes the formation of a pre-mRNA molecule, which is then processed to form mature mRNA (Figure 1). The resulting mRNA is a single-stranded copy of the gene, which next must be translated into a protein molecule.
Answer: The SA node
Answer choices are:
<span>A. </span>The AV node
<span>B. </span>The SA node
<span>C. </span>The purkinje fibers
<span>D. </span>The AV bundle
The SA node<span> is the heart's natural pacemaker consisting of a cluster of cells located in the upper part of the wall of the right atrium. (the right upper chamber of the heart). The electrical impulses are produced and sent out from there to regulate heartbeat. This is also called the sinus code. </span>
The correct answer is H+.
<span>Secretion from the peritubular capillary network into the convoluted tubules is a process called tubular secretion. This is an important process for both waste removal and acid-base balance. The secretion step is usually used to remove drugs, toxins, and poisons, or other molecules such as potassium (K+) and hydrogen (H+). The secreted molecules come from the peritubular capillaries and pass through the interstitial fluid before going through the wall of the tubule into the lumen of the tubule.</span>
