Answer:
The type of chemical mutagen to choose depends on the intended effect. In this case, the best ones are acridines and nitrous acid.
Explanation:
Brenner et al. proposed that acridines induce mutations by causing deletions or additions of single base pairs during replication. Acridines bind to DNA by intercalation between adjacent base pairs. Acridines inactivate extracellular phage by photodynamic action but the necessary conditions for this killing
are avoided in the procedure for acridine-induced mutation of reproducing phage. The lack of reported acridine-induced mutation in organisms other than phage raises some questions as to the generality of its
mutagenesis, thus making it a good type of compounds to induce specific mutations.
In the other hand, nitrous acid deaminates the amino bases adenine, cytosine (and hydroxymethylcytosine) , and guanine in nucleic acids.
Analysis of the effect of differences of pH during nitrous acid treatment
of phage DNA showed that the rate of killing was affected similarly to
the rate of guanine deamination, and that the rates of induced r mutation was affected similarly to the rates of adenine and hydroxymethylcytosine deamination. Ascribing the induced mutations to deamination of adenine and cytosine is reasonable in terms of the hydrogen bonding of their products and the Watson-Crick base pairing schemes. Since this inorganic acid is molecule-specific, it would also be used to induce certain mutations in bacteria without causing transition mutations.
Answer:
True
Explanation:
the relative amount of a given substance contained within a solution or in a particular volume of space; the amount of solute per unit volume of solution;.
Answer: mole fraction of methanol = 0.590
mole fraction of ethanol = 0.410
Explanation:
We are given:
Equal masses of methanol 
and ethanol 
are mixed.
let the mass be x g.
Calculating the moles of methanol in the solution, by using the equation:
Calculating the moles of ethanol in the solution, by using the equation:
To calculate the mole fraction of methanol, we use the equation:
To calculate the mole fraction of ethanol, we use the equation:
Thus mole fraction of methanol is 0.590 and mole fraction of ethanol 0.410 in three significant figures.
Answer is: <span>b) 9,042 L.
Ideal gas law: p</span>·V = n·R·T.
p is the pressure of the gas.
V is the volume of the gas.
n is amount of substance.
R is universal gas constant.
T is temperature.
T₁ = 15°C = 288 K.
V₁ = 10,5 L.
T₂ = -25°C = 248 K.
V₂ = ?
V₁/T₁ = V₂/T₂
V₂ = 10,5 L · 248 K ÷ 288 K
V₂ = 9,042 L.
Answer:
25% thorium will left after 50 days.
Explanation:
Half life:
A nuclear half is the time period of radioactive material in which its amount remain halved.
In given question it is stated that the half life thorium-234 is 25 days. Which means after passing the 25 days the amount of thorium must be halved of original amount.
For example,
If the original concentration was 100%, than after 25 days it will be 50%.
After 50 days amount of thorium left:
Number of half life = T (elapsed) / T half life
Number of half life = 50/25
Number of half life = 2
At first half life amount of thorium left = 100/2 = 50
After second half life amount of thorium left = 50/2 = 25
Total amount decayed = 50+25 = 75
Amount left after 50 days = 100-75 = 25
25% thorium will left after 50 days.
