Excision is the right answer :)
Answer:
We mean that a cell changes to another type of cell.
Explanation:
<em>Stem cells </em>are a type of cell that has the potential to become a specialized cell, this change or differentiation, is possible thanks to the activation or deactivation of certain genes that promote (or inhibit) the expression of certain proteins that origins different types of cells (fmuscle cells, osteocytes, neurons). This differentiation happens when the cells receive cues internally ( through signals or contact between a group of cells and another or through transcription factors) or externally.
Then, a differentiated cell is a cell that had gone under the previously described process.
I hope this information is useful to you!
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.
False. Probably I don’t have much context
