Oxidation and reduction. ... It refers to electrochemical processes<span> involving electron transfer to or from a molecule or ion changing its oxidation state. This reaction can occur through the application of an external voltage or through the release of chemical energy.</span>
Answer:
Watson and Crick proposed the double helical model of DNA.
Explanation:
- This model says that DNA exist as double helix. It has two polynucelotide strands running in opposite direction i.e the strands are anti-parallel.
- Each polynucleotide strand is made up of several nucleotide liknked together by phophodiester bonds.
- The two strands are not coiled upon each other but the double strand is coiled upon itself around a common axis like the spiral stair case. Here base pairs forms the stairs and backbone of two strands form railing. Back bone contains sugar and phosphate.
- The base pairing is specific, adenine always pairs with thymine and guanine always pairs with cytosine. Thus if we see any base pair, it consists of one purine and one pyrimidine.
- The two strands of DNA thus show complementary base pairing.
- The strands are held together because of hydrogen bonding between the bases in opposite strand.
- One full helical turn involves ten base pairs and the base pairs are stacked 3.4 A apart.
- This form is called as B-form of DNA.
False. Government sanctioned activities to improve ecosystems have helped to protect areas of wildlife and ecosystems from development and human activity. Although not always wholly effective, government sanctioned activities are in place to protect.
The receptor molecule is the ones which allow different interaction to occur between the matrix and the cell.
<u>Explanation:</u>
Receptor molecules are the protein molecules that have the ability to bind the signaling molecules at the surface of the cell in order to send signals to the matrix. Those signals on receipt<em> </em>act as the channel of communication.
Thereby, the interaction between the cell and matrix is established. Usually, this is one of the kinds of interaction. Paracrine interactions are interaction within adjacent cells whereas the endocrine interactions are interaction with distant cells.
