Exam 2 quizzes
gaps left at the 5' end of the lagging strand
Recall our discussion in lecture regarding telomeres at the ends of our human chromosomes. These regions of our DNA replicate differently than the rest of our DNA. This difference in the way telomeres replicate is a consequence of:
formation of the mitotic spindle
Scientists are actively searching for drugs that can kill cancer cells. One drug called PTX comes from a tree. PTX disrupts the formation of microtubules in cells and stops mitosis. PTX must affect which one of the following mitotic events?
MPF
A cell's passage past the G2 checkpoint into mitosis is triggered by
17 %
Adenine makes up 33% of the nucleotides in a sample of DNA from an organism. Approximately what percentage of the nucleotides in this DNA sample will be cytosine?
each new DNA double helix consists of one old DNA strand and one new DNA strand
After DNA replication is completed,
volume increases faster than its surface area
As a cell grows and increases in size, its
b
As we discussed in lecture, Meselson and Stahl grew bacteria in a medium containing "heavy" nitrogen (15N) and then transferred them to a medium containing 14N. Which one of the results in the figure above would be expected after one round of DNA replication in the presence of 14N?
template DNA; 3'-to-5'; new DNA; 5'-to-3'
DNA polymerase III reads the _______________ in the ____________ direction and synthesizes the ____________ in the _____________ direction.
helicase; hydrogen
During DNA replication, the enzyme called _________________ unzips the complementary DNA strands by breaking _________________ bonds.
They help separate the sister chromatids.
During mitosis, what is the role of the spindle fibers?
7
Experiments have shown that the 23 pairs of chromosomes in the diploid nucleus of a human cell at G1 of the cell cycle contain about 7 picograms of DNA. Therefore, a cell at the start of Prophase II of meiosis contains about __________ picograms of DNA.
DNA contains phosphorus, whereas protein does not.
Hershey and Chase made use of which of the following facts in their experiment to determine if protein or DNA is the genetic material?
The new cells will have an incorrect number of chromosomes.
If DNA is not copied during the S phase of the cell cycle, which of the following statements most accurately describes what will happen after cell division?
3´-GTCCAATGC-5´
If one strand of DNA is 5´-CAGGTTACG-3´, the opposite (or complementary) strand is:
sugars and phosphates
In lecture we saw that DNA looks like a "twisted ladder" or double helix. If the "steps" of the DNA ladder are made up of nitrogenous bases, what are the "hand rails" or backbone of the DNA ladder made up of?
Nothing will happen to the G2 cell.
In the diagram below, a G1 cell is fused to a G2 cell. Which statement below best describes what will happen to the G2 cell after this fusion experiment? Only choose the answer that refers to what happens to the G2 cell!
Okazaki fragments
In the diagram of a DNA replication fork above, the numbers 1-4 label short pieces of DNA. These short DNA pieces are called:
2N-2N -2N -N 2N-N -N -N
In the figure above showing only the starting cell(s) and final products, mitosis and meiosis
metaphase
Look closely at the figure below of a cell undergoing mitosis. Which stage of mitosis will FOLLOW this one (in other words, which stage comes NEXT)?
Avery, McCarty, and MacLeod
Molecules from heat-killed S cells were purified. The molecules were tested for the ability to transform live R cells. The transforming agent was found to be DNA. Who performed this famous experiment that we discussed in lecture?
centrosome
The ________________ is a microtubule-organizing center in human cells and is seen during all phases of the cell cycle. As we discussed in class, it plays an important role in mitosis.
anaphase
The chromatids become independent chromosomes at which stage of mitosis?
II and III only ones in the middle
The diagram above shows a short section of a DNA molecule before and after replication. If the nucleotides used to replicate the DNA are radioactive, which strands in the replicated molecules to the right would be radioactive?
chromatid centromere
The part of the chromosome contained in the rectangle is called specifically a ________________, and the part of the chromosome indicated by the arrow is called the ____________.
it demonstrated that harmless bacterial cells had been permanently transformed through a change in the bacterial hereditary system.
The significance of Frederick Griffith's experiment in which he used two strains of Streptococcus pneumoniae bacteria is that:
RNA primer complementary to a preexisting DNA strand
The synthesis of a new DNA strand begins with the synthesis of a(n)
The 5' to 3' direction of one strand runs opposite to the 5' to 3' direction of the other strand.
We use the term "antiparallel" to describe what property of the two complementary strands of DNA?
The cyclin part of MPF is broken down.
What happens to MPF after mitosis is complete?
a reduction in chromosome length
Which ONE of the following would you expect of a eukaryotic cell lacking the enzyme telomerase?
A chromosome contains hundreds of genes, which are composed of DNA.
Which of the following statements correctly describes the relationship among DNA, a gene, and a chromosome?
Corresponding segments of non-sister chromatids are exchanged.
Which one of the following statements accurately describes what occurs when homologous chromosomes cross over?
Homologous chromosomes pair up.
Which one of the following statements describes something that chromosomes do in meiosis, but NOT in mitosis?
The new cells have two copies of half of the genetic information in the original cell.
Which one of the statements below correctly describes the relationship between cells at the end of telophase I of meiosis and the original cell at the start of meiosis?
one dominant allele and one recessive allele
With respect to a gene, what does the notation Pp mean to geneticists?
letter D
synthesizes rna primer
I & IV
which is g1