The DNA replication by the action of DNA polymerase takes place in the 3' to 5' direction on the leading strand. The lagging strand which has the opposite orientation or polarity as that of the leading strand requires a more time to get synthesised. The DNA replication of the lagging strand happens in short segments where a RNA primer forms a compliment with a part of the DNA segment on its 3' end. This RNA primer helps initiate the replication of the Okazaki fragments. When the replication on the lagging strand reaches its end, the RNA primer forms a compliment with the last bit of the strand. This small segment gets missed in the end as no more DNA is left to form a RNA primer-DNA compliment. Such shortening of the lagging strand in the replication process is the end-replication problem.
Telomeres are protective ends of the DNA strands. These ends contain a poly-A tail. When the lagging strand replication reaches its end, the RNA primer forms a compliment with the telomere and initiates the replication. This leads to the shortening of the telomere and not the coding segments on the lagging strand of DNA. The telomerase repairs the shortened telomere by re-synthesising it.
About 96% of freshwater in the United States is obtained from stream and river.
Freshwater refers to a source of water supply that is not salty. Water could be freshwater or salt water. Salt water is often unfit for many applications unless it is duly processed.
The United States has an abundance of freshwater supply that is used for various purposes such as domestic purposes, irrigation, industry, etc. About 96% of freshwater in the United States is obtained from stream and rives.
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The answer is <span>B. contains enzymes that begin the breakdown of proteins.
Saliva is watery substance secreted by salivatory glands. <em>It cleanses the mouth</em> and maintenance oral hygiene. <em>It moistens the food</em>, so the created food bolus could easier pass into the esophagus. It also <em>carries food chemicals to taste receptors</em> so they can be tested. It contains enzymes involved in the food digestions. Some of them are amylase, which begins the breakdown of the starch, and lipase, which begins the breakdown of triglycerides. <u>There are no enzymes in the saliva that break down proteins</u>.</span>
Answer:
A or B
Explanation:
To be honest both are accurate.
