Answer:
option d, b, c
Explanation:
Starch molecules taken into the mouth from food substances are processed to an extent of 30% of its digestion. this is carried out by a specialized protein/ an enzyme that is present in the saliva; called amylase or ptyalin. this enzyme acts on the substrate molecule which in this case is starch molecules and convert it into smaller chains of simple sugars that includes maltose and dextrin which is digested in the small intestine.
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.
<span>d. All of the above
These behaviors;
Spreading wings
Flattening feathers
panting
are all evolutionary process to maintain body temperature. Birds are warm-blooded animals. Also known as </span><span>homeotherms, which is defined as having the constant body temperature. This is a vital function for the survival of the specie.
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<span>c. are hollow
</span>
The bones of most birds are hollow in order for the weight of the birds to be light for them to fly.
Humus is a dark organic matter that is an important part of your soil
Humus consists of decomposing organic material. The process of creating humus is called Humification: decomposition of o<span>rganic matter into smaller and smaller molecules by the micro-organisms in the soil (mostly bacteria and fungi).</span>
