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 statement that is correct is that all cells have the same genes, but different genes are active in different cells.
Explanation:
Differentiation or specialization is a function that cells possess and is what allows them to have different types of cells and tissues.
Cell differentiation depends on genetic regulation, a mechanism that determines the specific genes that are expressed in a cell or tissue type.
All cells contain the same DNA, which is organized into chromosomes and contain the genes that determine specific characteristics. <u>There is cell differentiation because some genes can be expressed and others are suppressed, all due to genetic regulation</u>.
The other choices are wrong because:
- <em>The eyes look different from the liver, because they have the same genes, but only some are expressed.
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- <em>Differentiated cells and tissues do not lose their genes.
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- <em>All cells have DNA.</em>
Fishing until reaching an established quota that allows the fish population to rebound each season is a method of sustainable fishing
<h3>What is sustainability ?</h3>
The main objective of sustainability is for people to live in peace and harmony on Earth for an extended period of time. Specific definitions of sustainability are difficult to agree on and hence vary in the literature and across time
- Sustainability is often represented diagrammatically. The figure at the top of this page suggests that there are three pillars of sustainability – economic viability, environmental protection and social equity.
- Sustainability is important for many reasons including: Environmental Quality – In order to have healthy communities, we need clean air, natural resources, and a nontoxic environment. Growth - UNTHSC's enrollment continues to expand, thus we demand additional resources such as energy, water, and space.
Learn more about Sustainability here:
brainly.com/question/4677073
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Answer:
B. Asexual reproduction produces offspring identical to the parents, but sexual
reproduction produces offspring with traits from both parents
Answer:
Biodiversity is the basis of agriculture and our food systems. ... Agricultural biodiversity also performs ecosystem services such as soil and water conservation, maintenance of soil fertility, conservation of biota and pollination of plants, all of which are essential for food production and for human survival.
Explanation:
Hope this helps and have a great day!!!
