BIO 183 Exam 3
During a typical cell cycle, the interphase is composed of which of the following phases Select one: a. G0, G1, and G2 b. G1, S, and G2 only c. Prophase, metaphase, anaphase, and telophase d. G1, S, G2, and Mitosis e. Interphase is the gap between G1 and G2
G1, S, and G2 only
Where can telomeres be found? Select one: a. On the ends of eukaryotic chromosomes. b. Throughout eukaryotic chromosomes. c. Telomeres have nothing to do with chromosomes. d. On the ends of prokaryotic chromosomes. e. Throughout prokaryotic chromosomes.
On the ends of eukaryotic chromosomes.
The purines found in RNA are Select one: a. Adenine and uracyl b. Adenine and thymine c. Cytosine and thymine d. Cytosine and guanine e. Cytosine and uracyl f. Adenine and guanine
Adenine and guanine
Which of the following is true about tumors Select one: a. Malignant tumors can release cancerous cells in the bloodstream. These cells are called metastases. b. Tumors release angiogenic signals that attract blood vessels c. Tumors can sometimes be fought via immunotherapy d. Cancer is often the result of a single mutation e. All of the above are correct, except d
All of the above are correct, except d
In meiosis, sister chromatids move toward the opposite poles of a dividing cell during Select one: a. Anaphase 1 b. Prophase 2 c. Metaphase 1 d. Telophase 2 e. Both anaphase 1 and anaphase 2 f. Prophase 1 g. Anaphase 2 h. Metaphase 2 i. Telophase 1
Anaphase 2
What is the difference between the enzymes DNA polymerase I and ligase? Select one: a. DNA polymerase I binds to Okazaki fragments, removes the primers, and replaces them with DNA nucleotides. b. Ligase binds to Okazaki fragments, removes the primers, and replaces them with DNA nucleotides. c. DNA polymerase I attaches the fragments to make one single continuous strand. d. Ligase attaches the Okazaki fragments to make one single continuous strand. e. Both A and D are correct. f. Both B and C are correct. g. None of the above are correct.
Both A and D are correct.
How many checkpoints does a typical cell cycle have? Select one: a. 17 b. 3 c. 2 d. 5 e. 12
3
The p53 gene is known as a proto-oncogene Select one: True False
False
At the end of the G2 phase, a diploid cell with an n=4 has a total of _____ sister chromatids Select one: a. 8 b. 4 c. 32 d. 16
16
The membrane that forms at the end of telophase to separate daughter cells at the end of mitosis in plants is known as Select one: a. A septum b. Cytokinetic constriction c. Cleavage furrow d. Mitotic split e. A cell plate
A cell plate
Without telomerase Select one: a. Cells could replicate indefinitely b. The DNA replication process would contain many mistakes c. Sister chromatids could not separate during mitosis d. Hydrogen bonds could not be severed within the DNA double helix e. Chromosomes would shorten at the 3' ends at every DNA replication
Chromosomes would shorten at the 3' ends at every DNA replication
The genetic regulation of the various blood types observed in humans is a great example of Select one: a. Epistasis b. Incomplete dominance c. Mendelian genetics d. Polygenic inheritance e. Codominance
Codominance
Which of the following proteins is not part of the replisome? Select one: a. Polymerase 3 b. DNA ligase c. Helicase d. Primase e. Beta clamps f. Cyclin dependent kinases
Cyclin dependent kinases
The main replication enzyme involved in prokaryotic DNA copying is called Select one: a. DNA polymerase 1 b. DNA polymerase 2 c. Ligase d. DNA polymerase 3 e. Primase
DNA polymerase 3
Bacterial cells divide by mitosis Select one: a. True b. False
False
Based on the difference is organism complexity, you would expect a chimpanzee to have more chromosomes than a prawn (shrimp) Select one: a. True b. False
False
Centrioles are only found in a cell during the M phase of the cell cycle Select one: a. False b. True
False
DNA nucleotides have a hydroxyl group at the 2' position on the ribose Select one: a. False b. True
False
DNA polymerases can only work on the lagging strand of the replication fork once they are finished with the leading strand Select one: a. False b. True
False
In a cancerous cell, you would expect telomerase activity to be Select one: a. The same as in a healthy cell b. Higher than in a healthy cell c. Lower than in a healthy cell
Higher than in a healthy cell
The proteins that hold homologous chromosomes after replication are called Select one: a. Homologous chromosomes are NOT held together after replication! b. Kinetochores c. Cohesins d. Centromeres
Homologous chromosomes are NOT held together after replication!
DNA polymerases read the DNA Select one: a. In the 5' to 3' direction b. In either 3' to 5' or 5' to 3' direction - depending on the situation c. In the 3' to 5' direction
In the 3' to 5' direction
In his experiments, Mendel sometimes crossed tall pea plants with short ones. The outcome of such crosses would always express the dominant allele (either tall or short). If the outcome of such a cross had consistently been a medium size (independently of the conditions in which the plants were grown), the pattern of inheritance for these plants would most likely be called Select one: a. Pleiotropy b. Incomplete dominance c. Codominance d. Epistasis e. Polygenic inheritance
Incomplete dominance
Which of the following is true about a triploid organism with a n=3 during the G1 phase of the cell cycle Select one: a. It would have 3 linear chromosomes b. It would have 6 X-shaped chromosomes c. It would have 3 X-shaped chromosomes d. It would have 9 linear chromosomes e. It would have 6 linear chromosomes f. It would have 9 X-shaped chromosomes
It would have 9 linear chromosomes
Growth factors are typically Select one: a. Synaptic signals b. Cell-cell contact signals c. Endocrine signals d. Autocrine signals e. Paracrine signals
Paracrine signals
Cystic fibrosis is a disease in which people have a mutation in an ion channel called CFTR. This type of channel is found in multiple tissues throughout the body, and a simple mutation in this channel may be expressed in a multitude of ways (sweating disorder, digestive system malfunction, respiratory difficulties, etc...). This type of situation when a genetic mutation expresses itself in a multitude of phenotypes is called Select one: a. Pleiotropy b. Epistasis c. Codominance d. Polygenic inheritance e. Incomplete dominance
Pleiotropy
Which of the following is NOT a reason for mitotic cell division? Select one: a. Pollen production in flowers b. Fetal growth c. Tissue repair after injury d. Tumor formation e. Regular tissue regeneration
Pollen production in flowers
We established that many growth factors activate the cell cycle by binding to receptor tyrosine kinases (RTK). Sometimes, these RTKs get mutated, and permanently turned "ON." As a result, the cell cycle is stimulated even in the absence of growth factors. In light of this information, you would label the genes that encode for these RTKs as Select one: a. Proto-oncogenes b. Tumor suppressor genes
Proto-oncogenes
Growth factors affect the cell cycle by binding to Select one: a. Intracellular receptors b. Rb proteins c. G protein coupled receptors (GPCR) d. Receptor tyrosine kinases (RTK) e. Cyclin/CDK complexes
Receptor tyrosine kinases (RTK)
DNA replication is a Select one: a. Dispersive mechanism b. Semi-conservative mechanism c. Conservative mechanism
Semi-conservative mechanism
Typically, the longest phase of the cell cycle is Select one: a. Anaphase b. Telophase c. The G2 phase d. The S phase e. Prophase f. The G1 phase g. Metaphase
The G1 Phase
During mitosis, the protein complex that anchors the replicated chromosomes to the spindle apparatus is called Select one: a. The centromere b. The kinetochore c. A cohesin d. A centriole e. A histone
The kinetochore
A testcross aimed at determining the genotype of an unknown organism with dominant phenotype results in a 1:1 ratio of dominant and recessive phenotypes. Based on this ratio, what can you deduce about the genotype of the unknown organism? Select one: a. There is no way to tell from the information given. There could be many possibilities b. The unknown organism is homozygous recessive c. The unknown organism is homozygous dominant d. The unknown organism is heterozygous
The unknown organism is heterozygous
A human karyotype is composed of 22 pairs of autosomal chromosomes and 1 pair of sex chromosomes Select one: a. True b. False
True
A nucleosome is composed of 9 histones (1H1, 2H2A, 2H2B, 2H3, and 2H4) Select one: a. False b. True
True
A pair of mutated receptor tyrosine kinase that stay constantly phosphorylated could lead to uncontrolled mitosis, and ultimately formation of a tumor Select one: a. True b. False
True
A retinoblastoma (Rb) protein that loses its ability to bind to the E2F transcription factor would lead to an increase in cell proliferation. Select one: a. False b. True
True
Caspases are apoptosis-inducing proteins activated by tumor suppressor proteins such as p53 Select one: a. True b. False
True
Cyclin-dependent kinases (CDKs) can be activated or deactivated via phosphorylation and dephosphorylation Select one: a. False b. True
True
During prophase of mitosis, each replicated chromosome attaches to a different microtubule on the mitotic spindle apparatus Select one: a. False b. True
True
During the S-phase of the cell cycle, each chromosome has multiple replication bubbles Select one: a. True b. False
True
Telomerase contains a template of RNA nucleotides Select one: a. False b. True
True
The primers that are attached by DNA primase during DNA replication and made of RNA nucleotides Select one: a. True b. False
True
Transcription factors tend to bind to DNA at the level of the major grooves Select one: a. False b. True
True
