exam 3 chapter 6 – Flashcards
Unlock all answers in this set
Unlock answersquestion
What term describes a harmless, noncancerous or precancerous tumor?
answer
benign
question
Which term describes a cancerous tumor?
answer
oncogenic
question
What is the name of the process by which cancer cells break off of tumors and spread to other parts of the body?
answer
metastasis
question
____ is the cause of about one-third of all cancer deaths.
answer
smoking tobacco
question
The process by which cells of a malignant tumor can break away and start new cancers at distant locations is called ________.
answer
metastasis
question
Cancer cells within which of the following biopsy samples would be the best indicator that the cancer has metastasized and is circulating through the bloodstream?
answer
lymph node
question
Which of the following is not a known carcinogen?
answer
pet dander
question
Free radicals remove ________ from other molecules.
answer
electrons
question
Which of the following can neutralize dangerous free radicals within the body?
answer
antioxidants from dietary fruits and vegetables
question
Which of the following is a risk factor for colon cancer?
answer
advanced age
question
What are the two halves of a duplicated chromosome called?
answer
sister chromatids
question
Consider a strand of DNA with the sequence GAATTCGGCA. What is the sequence of the complementary strand?
answer
CTTAAGCCGT
question
What is the name for the region toward the middle of a replicated chromosome where sister chromatids are connected?
answer
centromere
question
Which of the following is a feature of DNA?
answer
The backbone of each strand is composed of alternating sugar and phosphate groups.
question
In a certain species of animal, 33% of the bases in its DNA are A. What percent of the bases are C?
answer
17%
question
The two halves of a duplicated chromosome are called ________ (two words).
answer
sister chromatids
question
________ (two words) is the enzyme that assists in DNA synthesis.
answer
DNA polymerase
question
In a bacterial species, 20% of the bases in its DNA are C. What percent of the bases are G?
answer
20%
question
The term "semiconservative replication" refers to the fact that
answer
the DNA molecule includes a parental strand and newly created DNA strand.
question
Nucleotides in opposing strands of DNA that bind to each other are called
answer
complementary.
question
The scientists that first described the structure of DNA were
answer
Watson and Crick.
question
Bacteria are single cells that replicate themselves by binary fission, resulting in genetically identical daughter cells. These cells undergo
answer
asexual reproduction.
question
If a double-stranded DNA molecule is like a twisted rope ladder with handrails and steps, what would the steps in the ladder represent?
answer
nitrogenous bases
question
DNA polymerase moves along the length of the unwound helix, starting at the end of one strand and finishing at the end of the other strand. As shown in this figure, what is the result of this phenomenon?
answer
The DNA polymerase moves toward the unwound helix on one strand of DNA and away from it on the other strand.
question
Which type of cell division produces daughter cells that are identical to the original cell?
answer
mitosis in animals
question
Which of the following is a phase that occurs during mitosis?
answer
metaphase
question
Which of the following is the correct order of events in the cell cycle?
answer
G1, S, G2, mitosis, cytokinesis
question
During which part of mitosis does the nuclear envelope break down?
answer
prophase
question
Which of the following is the correct order of events in mitosis?
answer
prophase, metaphase, anaphase, telophase
question
Consider a cell that underwent mitosis but not cytokinesis. The result would be
answer
a cell with two nuclei.
question
A cell plate forms during which process?
answer
cytokinesis in a plant cell
question
Which carbohydrate is used to create the cell wall during cytokinesis in plant cells?
answer
cellulose
question
During which phase of mitosis are the replicated chromosome aligned in the middle of the cell?
answer
metaphase
question
During which phase of mitosis does the cytoplasm divide?
answer
telophase
question
During which phase of mitosis do sister chromatids separate to opposite poles of the cell?
answer
anaphase
question
Most cells spend most of their time in which phase?
answer
interphase
question
Which of the following cells spends the most time in interphase?
answer
nerve cells in the brain
question
Why do chromosomes resemble the letter X when viewed during metaphase?
answer
Because there are two sister chromatids joined at a point in the middle (the centromere).
question
Most organelles duplicate during
answer
the G1 phase of interphase.
question
Microtubules connect centrioles to ________ during mitosis.
answer
centromeres
question
During the metaphase checkpoint, the cell checks whether
answer
its chromosomes are properly attached to microtubules.
question
What is the difference between oncogenes and proto-oncogenes?
answer
Proto-oncogenes encode proteins that help a cell divide under favorable conditions; oncogenes encode proteins that help a cell divide under unfavorable conditions.
question
A gene that encodes a protein necessary for a cell to stop at checkpoints is an example of a(n)
answer
tumor-suppressor gene.
question
What is the process by which a tumor attracts and redirects blood vessels to keep it supplied with O2 and nutrients?
answer
angiogenesis
question
Which of the following is a common feature of cancer cells?
answer
metastasis
question
The multiple-hit model of cancer means that
answer
multiple mutations are required to cause most forms of cancer.
question
________ are places in the cell cycle where proteins survey the cell to make sure that conditions for a favorable cell division have been met.
answer
Checkpoints
question
Which of the following is a protein that acts as a tumor suppressor by fixing damaged DNA in cancerous cells?
answer
BRCA2
question
Mutations of the gene that encodes p53 result in
answer
damaged DNA proceeding through mitosis.
question
The surgical removal of cells, tissue, or fluid that will be analyzed to determine whether they are cancerous is called a ________.
answer
biopsy
question
The most common type of cancer that people in the United States die from is
answer
lung cancer.
question
Most forms of chemotherapy target which feature of cancer cells?
answer
cell division
question
Radiation therapy works primarily by
answer
damaging DNA in cells so that cells can no longer grow and divide.
question
A scientist who observes cancer cells under a microscope would likely see
answer
disorganized cells.
question
A ________ is a surgical instrument used to perform biopsies.
answer
laparoscope
question
Elevated CA125 in a patient's blood may indicate ovarian cancer. However, routine screening of CA125 levels is not practical due to which of the following reasons?
answer
CA125 levels vary among individuals.
question
The members of a pair of nonsex chromosomes are called
answer
homologous chromosomes.
question
Different versions of the same gene are called
answer
alleles.
question
Normal sperm or egg cells in a human
answer
have one copy of each chromosome.
question
Tetraploid organisms have four copies of each chromosome instead of the two copies that humans have. How many copies of each chromosome end up in a gamete produced by a tetraploid organism?
answer
2
question
A normal human cell containing 22 autosomes and a Y chromosome is a(n)
answer
sperm cell.
question
A normal human cell containing 44 autosomes and two X chromosomes is a(n)
answer
somatic cell of a female.
question
Homologous chromosomes separate during
answer
meiosis I.
question
Sister chromatids separate during
answer
meiosis II and mitosis.
question
Crossing over occurs during
answer
prophase I of meiosis I.
question
Genes that are located on the same chromosome are called
answer
linked genes.
question
How does crossing over increase genetic diversity?
answer
Crossing over increases the number of distinct combinations of genes that may be present in a gamete.
question
_______ are specialized cells (egg cells and sperm cells, for example) used for sexual reproduction.
answer
Gametes
question
Which of these conditions is caused by nondisjunction of autosomal chromosomes?
answer
Trisomy 21 or Down syndrome
question
Mutations are only passed from parent to child if the mutation occurs in the gonads that will be used to produce
answer
a gamete.
