All EXCEPT which of the following would be considered a good model of
genetic organisms for studying development?
Arabidopsis
humans
Drosophila
C. elegans
b. humans
Humans are not good model organisms for many reasons, such as
the ethical issues surrounding experimentation.
What are maternal-effect genes?
genes inherited from the mother
genes transcribed in
the mother that regulate expression of genes in the offspring
genes transcribed in the offspring that regulate expression of genes
in the mother
genes transcribed in the mother that negate the
genes of the father
genes transcribed in the mother that regulate expression of genes in
the offspring
The products of maternal-effect genes are deposited in the egg
and regulate the expression of zygotic genes.
Immediately after fertilization of a Drosophila egg, the zygote
nucleus undergoes a series of divisions. Subsequent nuclear migration
generates a(n) ________.
zygote
syncytial blastoderm
cleavage nucleus
maternal effect
homeodomain
syncytial blastoderm
What are the three subsets of segmentation genes that divide the
embryo into segments along the anterior-posterior axis?
gap,
pair-rule, and segment polarity
anterior, posterior, and
terminal
even-skipped, fushi tarazu, and hairy
bithorax, ultrabithorax, and antennapedia
gap, pair-rule, and segment polarity
Segmentation genes divide the embryo into a series of segments.
In Drosophila, the sequential order of the function of segmentation
genes is ________.
pair-rule, transdeterminal, gap
transdeterminal, gap, pair-rule
gap, pair-rule,
segment-polarity
segmentational, helical, spherical
gap, segment-polarity, pair-rule
gap, pair-rule, segment-polarity
Cancer is best described as a ________.
viral disease
genetic disorder at the cellular level
genetic disease at the
gametic cell level
bacterial disease at the somatic cell level
genetic disorder at the cellular level
Correct
The location of genetic mutations and how they
occur vary greatly. However, all cancers result from a genetic
disorder at the cellular level.
Driver mutations provide a growth advantage to a tumor cell. Which
type of mutation is known to accumulate in cancer cells but has no
direct contribution to the cancer phenotype?
alteration mutations
insignificant mutations
passenger mutations
indirect mutations
carrier mutations
passenger mutations
Which of the following three general mechanisms appear to be involved
in the conversion of proto-oncogenes to oncogenes?
familial, sporadic, phosphorylation
transdetermination, mutation, allosteric interactions
suppression, tabulation, projection
point mutations,
translocations, overexpression
inversions, translocations, methylation
point mutations, translocations, overexpression
The gene p53 is called the "guardian of the genome" because
it corrects mutations in the spindle apparatus before nondisjunction
can occur.
True
False
false
In Drosophila, maternal-effect genes are influential in determining
the anterior-posterior organization of the developing embryo.
True
False
True
Segmentation genes, such as the pair-rule class, are inherited
through mitochondrial DNA in Drosophila.
True
False
False
Which of the following statements describes metastasis?
The ability to form secondary tumors at another site
Loss of contact inhibition
It is the ability to divide
uncontrollably.
A class of genes that initiate apoptosis
The ability to form secondary tumors at another site
What is the relationship between proto-oncogenes and oncogenes?
Oncogenes are mutant forms of proto-oncogenes.
Both
must be activated to halt cell division.
Both are involved in
arresting the cell cycle.
Oncogenes are versions of
proto-oncogenes that have been permanently switched off.
Oncogenes are mutant forms of proto-oncogenes.
Proto-oncogenes are normal cellular genes. Mutations can cause
these to be permanently switched on, leading to uncontrolled cell
division and cancer.
What is the role of the p53 protein in the cell cycle in normal
cells?
It temporarily arrests the cell cycle in G1 before entering S.
It causes cells to enter G0 and stop dividing.
It
prevents cells from exiting the cell cycle and undergoing apoptosis.
It binds to cyclin-dependent kinases to selectively
phosphorylate certain proteins.
It temporarily arrests the cell cycle in G1 before entering S.
The p53 protein apparently arrests the cell cycle until any DNA
damage has been repaired.
A tumor-suppressor gene normally functions to suppress cell division.
True
False
True
When the normal retinoblastoma protein is dephosphorylated, it acts
to suppress cell division by binding to and inactivating the E2F
transcription factor.
True
False
True