<span>it was molecular structure of DNA this was appeared 1n April 1953 Watson and Crick presented the structure of DNA- Helix.it carried the genetic information. the DNA Molecule shaped in twisted ladder.franklin produced an X- ray photograph.
DNA structure is made of molecules called nucleotide. Watson and crick also work on 3-D structure of DNA. this mark the history in molecular biology to understanding the genes control and genetic information.they also work on cell.they use stick and ball to understand to test their idea.</span>
Answer:
MNP stands for the most probable number which is used for finding out the concentration of viable bacteria in a sample. It is commonly used to check the quality of water and its safety. Usually, the presence of fecal coliform bacteria is checked in this test.
Principle of MNP: The sample which is to be tested is diluted serially and then inoculated into a broth medium containing lactose. If coliforms are present in the tube than it will consume lactose and release acid and gas.
Color change represents acid production and gas trapped in the Durham tube represents the gas production by bacteria. Then the number of tubes at each dilution that showed positive results are compared with standards to determine the most probable number of the bacteria.
Because the AV node takes on the role of a very important delay in the cardiac conduction system. Without this delay, the atria and ventricles would contract at the same time.
<h3>Cardiac conduction system</h3>
The conduction system of the heart sends electrical signals, usually generated by the sinus nodes, causing the heart muscle to contract. Pacemaker signals originating from the sinus node travel through the right atrium to the atrioventricular (AV) along the bundle of His and through branches of the bundle, causing myocardial contraction. This signal first stimulates contraction of the right and left atria then flows to the right and left ventricles. That electric current then allows blood to be pumped throughout the body.
Learn more about sequence of travel by an impulse through the cardiac conduction system at brainly.com/question/28269433
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Answer:
The rectum is located at the "left lower portion" of the abdominal pelvic region.
Explanation:
The rectum is present at the left lower portion of the abdominal area which gives partial view of the small intestine. Descending to it a sigmoid colon, rectum, left ureter and urinary bladder is present. The diameter of the rectum is like a sigmoid colon near the onset. However, it is bigger at the anus as it forms the rectal ampulla near it. The main function of the rectal ampulla is to store the feces for temporary period. The size of the rectum is 8 inch and it has connected the colon as well as the anus.
Answer:
Epiglottis
Explanation:
The epiglottis is a leaf like structure tat rests above the voice box/larynx and its main function is to seal off the windpipe during eating, so that food is not accidentally inhaled down the wind pipe. When water goes down the wrong pipe, it goes down the windpipe instead of the oesophagus resulting in water going to your lungs which causes the coughing as a protective reflex to clear the windpipe
