Answer:
A
Explanation:
it helps create fertile soil (ed(g)enuity correct answer)
Answer:
Principles of Geology
Explanation:
J. Henslow gifted Darwin the first volume of Principles of Geology, written by Charles Lyell. The book explains about the old age of the earth. Accordingly, the slow rate of several geological processes suggests that the earth is very old.
Darwin read the book as the ship was crossing the Atlantic and learned about geological processes occurring over the millions of years. For example, he learned that the earth's surface was not formed by some catastrophic event.
In his book, Lyell explained the slow and gradual geological processes like erosion gave rise to the vast landscapes present on the earth's surface.
Darwin compared the time taken by geological processes to form the earth's surface and reasoned if these millions of years were enough to support the evolution of species.
Answer: The bacteria transformed with this particular plasmid will form white colonies on the plates containing ampicillin and Xgal.
Explanation: The lacZ gene produces an enzyme called β-galactosidase which is responsible for the breakdown of lactose into glucose and galactose. The lacZ gene is one of the three genes (the other two being lacA and lacY) of the lac operon which is responsible for the transport and mechanism of lactose in E. coli and many other bacteria.
In recombinant DNA technology, when a plasmid is to be used to transform a host cell, such markers are used to help screen the transformed cells from the ones that have not taken up the plasmid. Xgal present in the plates is an artificial substrate which is hydrolyzed by
β-galactosidase into 5-bromo-4-chloro-indoxyl which will dimerize and oxidise into 5,5'-dibromo-4,4'dichloro-indigo. This is a blue pigment which will give blue color to the bacterial cells. Introducing a DNA fragment in this lacZ gene will make it non-functional so it will not be able to produce the enzyme.
Therefore, when a bacterial cell is transformed with a plasmid containing ampicillin resistance gene and a DNA fragment introduced in the lacZ gene and then grown on plates containing ampicillin and Xgal, white colored colonies will appear. The white colonies will show the bacterial cells that have successfully taken up the plasmid with the DNA fragment incorporated in the lacZ gene as this will render the gene non-functional and will not produce β-galactosidase which will breakdown Xgal to give blue colonies. Since the plates contain ampicillin, only the bacterial cells that have been successfully transformed with the plasmid ( the ones that have the DNA fragment and the ones without it) will grow as the ampicillin resistance will give them resistance against ampicillin in the plates. The bacterial cells that have not taken up the plasmid will not be resistant to ampicillin and will not form colonies on the plate.
This is called blue-white screening which is used to identify successfully transformed host cells. A picture of this is given in the attachment, taken from the following website:
https://www.mun.ca/biology/scarr/Blue_&_White_Colonies.html
Answer:
The main role of carbonic anhydrase in humans is to catalyze the conversion of carbon dioxide to carbonic acid and back again. However, it can also help with CO2 transport in the blood which in turn helps respiration. It can even function in the formation of hydrochloric acid by the stomach.
Explanation:
<span>The importance of the G0 phase is that during cell division when the cell get a signal that there are enough of cells (not more required) or there is a mutation in the cell that need to be fixed before they differentiate fully or the cell during its division gets damage then it is signalled to rest, and it is this phase that cell leave the cycle and quit dividing. It could be temporary resting period (so when cell again required, or damaged got fixed) then the cells will again join the cycle and continue to divide again or it can also be permanent for example neurons, which are resting in G0 phase and never divides again.</span>