Why might humans purposefully cause disturbances in an ecosystem? Explain

If a substance can be separated by physical means and it is not the same throughout, what is it? a heterogeneous mixture a homog

GenaCL600 [577]

<h2>answer:</h2>

a heterogeneous mixture

<h2>explanation:</h2>

A heterogeneous mixture is commonly any mixture that is not uniform in combination - it's a non-uniform mixture of smaller fundamental particles. Using different means, the particles in the mixture can be separated from one another. In a heterogeneous mixture, the elements do not mix completely, and the individual items that form the mixture can be identified. Heterogeneous mixtures can typically be separated back into their original components by chemical or physical means.

5 0

3 years ago

What would most likely happen to a native predator species if a nonnative predator species were introduced to an area?

Fantom [35]

Answer:

B. The native species population would decrease because the nonnative species would be competing for food sources.

Explanation:

This question is describing the effect of invasive species. Invasive species are foreign species i.e. not native to a habitat or area, introduced into the area with the ability to outcompete and negatively affect the native species of that area.

Invasive species compete with the native species for food, space, mate etc., and tend to outgrow them. Hence, if a nonnative predator (invasive) species were introduced to an area, the native predator species in that area would decrease because the nonnative species would be competing for food sources.

5 0

2 years ago

Earth is tilted 23.5° on its rotational axis. This tilt affects the amount of direct sunlight received by Earth’s hemispheres th

vlada-n [284]

D.constant sunlight .................................

5 0

2 years ago

Read 2 more answers

Based on changes in human populations from ancient times to the present, what do you think might have happened to movement of hu

Nezavi [6.7K]

Answer:

All of them are right

Explanation:

7 0

2 years ago

A DNA fragment is introduced into the lacZ gene of a plasmid, which also contains an ampicillin resistance gene. What is the app

zhenek [66]

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

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2 years ago