Sulfur emissions from industry combine with water in the atmosphere and form acid rain. A new factory is built very close to the lake that Josh visits often. By examining the table that shows what pH range different species can survive, Josh decides that the aquatic life will be affected by the changes in pH that the lake. Josh correctly decides that organisms that will be the most affected are
A) perch and frogs.
B) mayfly and bass.
C) snails and clams.
D) frogs and salamanders.
The correct answer is option (C) snails and clams.
Acid rain is formed when oxides of sulfur and nitrogen combine with water molecules. Industries are one of the major contributors to acid rain. pH is a measure of acidity or alkalinity in water.
A factory built close to the lake can cause acid rain which affects the pH of the lake. Any change in the pH of the lake has an effect on the organisms in it. A pH of 7 is considered to be neutral and pH values below 7 indicates acidity and pH values above 7 indicates alkalinity. Organisms have an acid tolerance level beyond which they are affected and can die. Perch has an acid tolerance of up to pH 4.5 and frogs can tolerate an acidic pH of 4.0. The acid tolerance level of Mayfly and Bass is a pH of 5.5. Salamanders can tolerate an acidic pH of 5. Whereas, Snails and Clams have a very less pH tolerance of 6. They are highly susceptible to acidic pH.
Thus, Josh correctly decides that organisms that will be the most affected are snails and clams.
Answer:
The correct answer is B high levels of lactose and high levels of cyclic AMP.
Explanation:
Lac operon contain 3 regulatory genes and 3 structural genes.In presence of lactose the repressor molecule that is encoded by Lac I gene cannot bound to the operator region.
Bacause the lactose interact with the repressor and change its conformation so that it cannot repress the expression of the structural genes of lac operon.
On the other hand cyclic AMP is a positive regulator of lac operon .The interaction of cyclic AMP with the promoter region of lac operon stimulates the binding of RNA polymerase in the promoter region to boost the expression of structural genes of lac operon such as Lac Z,Lac Y and Lac A.
By taking daily antibiotics, people are encouraging resistance by getting their immune systems used to the formulas. Antibiotic resistance<span> occurs when bacteria change in a way that reduces the effectiveness of drugs, chemicals, or other agents designed to cure or prevent infections. The bacteria survive and continue to multiply, causing more harm. I think that people can help by not taking antibiotics for every little pain they have, instead try other simple remedies and only use medicines in cases where other remedies won't help. </span>
Answer:
(C) Aminoacyl-tRNA synthetases have an additional active site that binds to non-cognate tRNAs. The tRNAs that bind to this second active are hydrolyzed and released from the enzyme.
Explanation:
In case of translation, proof reading is done by aminoacyl-tRNA synthetases only. Aminoacyl-tRNA synthetases have two mechanisms to avoid error during translation which are mentioned as under:
<u>(1) Chemical proof reading:</u> Incorrect amino acids rather than being hydrolyzed in catalytic pocket get hydrolyzed in editing pocket and thus they hardly get attached to tRNA.
For example: For distinguishing similar amino acids like isoleucine and valine, isoleucyl-tRNA synthetase uses a second active site which is meant for only valine not for isoleucine. In this particular site, valine which had entered the enzyme is cleaved away with the help of editing reaction after which the enzyme is well prepared to process isoleucine which is the correct amino acid for this enzyme.
<u>(2) Kinetic proof reading: </u>Even if an incorrect amino acid has entered a particular aminoacyl-tRNA synthetase, it does not cause appropriate conformational change in the enzyme because of which the incorrect amino acid loosens from the enzyme and does not get incorporated.
Note: In this example, only chemical proof reading is mentioned not kinetic proof reading.
Answer:
it's A
Explanation:
it's explaining your idea.
