Two pathways, homologous recombination and nonhomologous end joining (NHEJ), can repair double-strand breaks in DNA. If homologous recombination is an errorfree pathway whereas NHEJ is not always error free, why is NHEJ used most of the time in eukaryotes?

Which statement concerning telomeres is not true? A. They are found on the ends of chromosomes. B. They consist of DNA and sugars. C. They protect chromosomes. D. Replication is a problem in most cells.

Let G = (V, E) be a loop-free connected undirected graph with $|V| \geq 3.$ If G has no articulation points, prove that G has no pendant vertices.

Which repair pathway recognizes DNA damage during transcription? What happens if the damage is not repaired?

AVS Industries has determined that the combined fixed and variable expenses for the production and sale of 800,000 items are $24,000,000. What is the price at the breakeven point for this Item?

Most computer languages include a function that can be used to generate random numbers. In Excel, the RAND function can be used to generate random numbers between 0 and 1. If we let x denote a random number generated using RAND, then x is a continuous random variable with the following probability density function.

$$f ( x ) = \left\{ \begin{array} { l l } { 1 } & { \text { for } 0 \leq x \leq 1 } \\ { 0 } & { \text { elsewhere } } \end{array} \right.$$

Graph the probability density function.

a. Acridine orange is an effective mutagen for producing null alleles by mutation. Why does it produce null alleles? b. A certain acridine-like compound generates only single insertions. A mutation induced with this compound is treated with the same compound, and some revertants are produced. How is this outcome possible?

Determine the value of the literal numbers in each of the given matrix equalities. If the matrices cannot be equal, explain why.

$$\begin{bmatrix} x & 2y & z \\ r/4 & -s & -5t \end{bmatrix} = \begin{bmatrix} -2 & 10 & -9 \\ 12 & -4 & 5 \end{bmatrix}$$

Davinder ( D ) and Mikhail ( M ) were 2 miles apart when they began walking toward each other. D walks at a constant rate of 3.7 miles per hour, and M walks at a constant rate of 4.3 miles per hour. When they started, D's dog, who runs at a constant rate of 6 miles per hour, ran to M and then turned back and ran to D. If the dog continued to run back and forth until D and M met and the dog lost no time turning around, how far did it run?

Consider the following linear system.

$$\left\{ \begin{array} { c } { x + y = 3 } \\ { 3 x - y = 1 } \end{array} \right.$$

(a) Express the system as a matrix equation AX = B. (b) If a linear system is expressed as a matrix equation AX = B, how do we solve the system? Solve the system in part (a).

Consider a multiple-choice examination with 50 questions. Each question has four possible answers. Assume that a student who has done the homework and attended lectures has a 75% probability of answering any question correctly.

A student must answer 43 or more questions correctly to obtain a grade of A. What percentage of the students who have done their homework and attended lectures will obtain a grade of A on this multiple-choice examination?

The binomial coefficient $\binom{n}{k}$ is the number of k-element subsets of an n-element set. Here is another way to think of $\binom{n}{k}$. Let A be an n-element set and suppose we have we supply of labels; we have k labels that say "good" and n-k labels that say "bad". In how many ways can we affix exactly one label to each element of A?

The _ of a plane wave is perpendicular to the direction of motion of this wave.

The average price for a gallon of gasoline in the United States is $3.73 and in Russia, it is$3.40 (Bloomberg Businessweek, March 5-March 11, 2012). Assume these averages are the population means in the two countries and the probability distributions are normally distributed with a standard deviation of $.25 in the United States and a standard deviation of$.20 in Russia. a. What is the probability that a randomly selected gas station in the United States charges less than $3.50 per gallon?