You got all of them right if you need help with fourth one I can’t see it
Answer:
gain; presence
Explanation:
The Ames test is a lab methodology used to determine whether a particular chemical substance can trigger mutations in an organism, which can be used to indicate whether exposure to the target chemical compound is associated with a greater risk of developing cancer. The Ames test can use a strain of <em>Salmonella typhimurium</em> carrying mutations in a key gene that encodes a protein involved in histidine biosynthesis. In consequence, this <em>S. typhimurium</em> strain is considered to be a 'histidine auxotroph' which is unable to synthesize histidine residues. After exposure to the target chemical compound, bacteria are then cultured in a medium lacking histidine. Subsequently, bacteria that regain the ability to synthesize histidine proliferate to form colonies. Finally, the number of these colonies is then compared with the number of mutants in absence of the potential mutagen, enabling thus the determination of the mutagenic potential of the target chemical compound.
Answer:
If fracking can contaminate city water, it might also poison nearby rivers
Explanation:
It is a pretty challenging question, but in my opinion this is the correct answer. I have mor information for you,m fire does not extiguish with water because water has Oxygen and oxygen is what keeps fire alive, if you want to extinguish it you have to trap fire with CO2 or carbondioxide wich is the chemical that kills fire. I dont know if this answert is enough for you but I hope its the correct one.
The freshwater Alga Spirogyra form long threadlike colonies called filaments.
Answer:
A process that increases quantity over time.
Explanation:
The formula for exponential growth of a variable x at the growth rate r, as time t goes on in discrete intervals (that is, at integer times 0, 1, 2, 3, ...), is:
![X_{t}= X_{0} (1+r)^{2}](https://tex.z-dn.net/?f=X_%7Bt%7D%3D%20X_%7B0%7D%20%281%2Br%29%5E%7B2%7D)
Exponential growth is a process that increases quantity over time. It occurs when the instantaneous rate of change of a quantity with respect to time is proportional to the quantity itself.