When it is winter in the Northern Hemisphere, the Southern Hemisphere faces the Sun more directly and thus experiences warmer temperatures than the Northern Hemisphere. Meaning that the date is June 21- summer
The muscle cells divide through Mitosis, a cellular division comprised of several other substeps.
The final step of the cell division is the cytokinesis by which two new cells are formed from cell with a multiple number of nucleus after the replication process. This steps follow the telophase.
It is kind of difficult for me even, but I know that neutral objects<span> have an even amount of opposite </span>charges<span>. When </span>brought near a charged object<span> the </span>neutral's<span> protons will lean toward excess electrons on the </span>charged<span> one. A positively </span>charged object<span> will attract the neutrals electrons to move toward it. I hope that kind of helped. Sorry if I couldn't give a direct answer! Its kind of hard for me too and I'm an A+ student in bio</span>
Answer:
The correct answer is: d. REs activity is best preserved by freezing the RE and thawing it out for brief periods of time as needed.
Explanation:
- Restriction enzymes can be defined as endonucleases that can recognize specific nucleotide sequence in a DNA (Deoxyribonucleic acid) sequence and cause breakage of phosphodiester bond in the DNA at the target site. Hence, it has the capacity of cleaving a DNA sequence.
- These are made up of proteins which are required to be present in the accurately folded conformation in order to function.
- Any form of alteration in the three-dimensional structure of the protein induced due to physical, chemical, mechanical or physiological factors can cause denaturation of the protein which in turn can render the protein non-functional.
- Freezing of restriction enzymes (REs) directly without the use of glycerol will cause the movement of water molecules within the proteins as well layering of water molecules on the protein surface.
- At low temperature these water molecules change to ice crystals which can alter the conformation of the protein or can cause breakage of peptide bonds in the proteins by physical force.
- This can cause the protein to get denatured and hence non-functional.
- Hence, it is never advisable to preserve REs by freezing directly without glycerol.
- Glycerol forms a layer around the protein molecules and prevents the protein molecules from coming into direct contact with the water molecules and hence prevents protein denaturation.
