New Jersey Institute of Technology

For example, for a class of 20 students, their genotype distribution was as follows:
Group 1: 5 students with (+/+) genotype (homozygous for the + allele)
Groups 2 and 4: 11 students (+/–) genotype (heterozygous)
Group 3: 4 students = (–/–) genotype (homozygous for the – allele)
-Determine the total number of + alleles by counting the number of students who are
homozygous for the allele and multiplying by 2, and counting the heterozygous students
once, since they carry only one copy of the + allele.
-Number of + alleles in the example above: ________
-Number of + alleles in your class:_______
 The allelic frequency is the ratio of the number of a particular allele to the total number of
alleles in the population. Determine the allelic frequency for the + allele.
-For the example above: _________
-For your class: _________

What is the allelic frequency for the – allele?
-For the example above: _________
-For your class: _________

 Practice Problems, Physics 111 Common Exam 2, Spring 2024
Chapters: 4, 5, 6 and 7

Consider the following program:

  P1: {                                    P2: {

 shared int x;                                   shared int x;

x = 10;                                                x = 10;

while (1) {                                                        while ( 1 ) {

   x = x - 1;                                            x = x - 1;

   x = x + 1;                                            x = x + 1;

   if (x != 10)                                                       if (x!=10)

    printf(“x is %d”,x)                                                     printf(“x is %d”,x)

    }                                                                                    }

  }                                                                       }

Note the scheduler in a uniprocessor system would implement pseudo-parallel execution of these two concurrent processes by interleaving their instructions, without restriction on the order of the interleaving.

Show a sequence (i.e., trace the sequence of interleavings of statements) such that the statement “x is 10” is printed.

If a process exits and there are still threads of that process running, will they continue to run?

Consider an environment in which there is a one-to-one mapping between user-level threads and kernel-level threads that allows one or more threads within a process to issue blocking system calls while other threads continue to run. Explain why this model can make multithreaded programs run faster than their single-threaded counterparts on a uniprocessor computer.

 In the discussion of ULTs versus KLTs, it was pointed out that a disadvantage of ULTs is that when a ULT executes a system call, not only is that thread blocked, but also all of the threads within the process are blocked. Why is that so?