Answer: (SL) Semilunar Valves
Explanation:
A Nerve electrical impulse only travels in one direction. There are several reasons nerve impulses only travel in one direction. The most important is synaptic transport.
In order for a "nerve impulse" to pass from cell to cell, it must cross synaptic junctions. The nerve cells are lined up head to tail all the way down a nerve track, and are not connected, but have tiny gaps between them and the next cell. These tiny gaps are called synapses.
When you get a nerve firing, you have probably heard that it is an electrical impulse that carries the signal. This is true, but it is not electrical in the same way your wall outlet works. This is electrochemical energy. Neurotransmitters are molecules that fit like a lock and key into a specific receptor. The receptor is located on the next cell in the line. When the neurotransmitter hits the receptor on the next cell in line, it signals that cell to begin a firing as well.
This will continue all the way down the length of the nerve track. In a nutshell, a nerve firing results in a chain reaction down the nerve cell's axon, or stemlike section. Sodium (Na+) ions flow in, potassium (K+) ions flow out, and we get an electrochemical gradient flowing down the length of the cell. You can think of it as a line of gunpowder that someone lit, with the flame traveling down the length of it. Common electrical power is more like a hose full of water, and when you put pressure on one end, the water shoots out the other.
Therefore, nerve impulses cannot travel in the opposite direction, because nerve cells only have neurotransmitter storage vesicles going one way, and receptors in one place.
Answer:
The information carried by DNA is incorporated in a code specified by the: specific nucleotide sequence of the DNA molecule. The enzyme DNA ligase is responsible for: linking short DNA segments.
Explanation:
DNA ligase <span>s responsible for creating the covalent bonds that connect the sugar phosphate backbone of the new DNA molecules</span>
Answer:
The correct answer would be - MMR would be hindered because both strands would be unmethylated and both would appear as new DNA strands and it would not be able to determine which strand has the error
.
Explanation:
In gene expression or DNA replication, the enzyme responsible for the synthesis of DNA from nucleoside triphosphate causes errors sometimes such as mismatch base pair that result in a change in genetic makeup.
For MMR, the DNA template and the strand formed required easily to be differentiated. As the newly synthesized strand is unmethylated and the DNA template strand is methylated results in DNA remain hemimethylated for a very short period.
After MMR, DNA adenine methylase enzyme that transfers a methyl group to the adenine of the sequence 5'-GATC-3' daughter strand formed.
Mutated DAM or DNA adenine methylase will not be able to transfer methyl group which leaves both template and daughter strands unmethylated and mismatch repair would be hindered as it will not be able to identify.
