EXAM 2 GENETICS PORTAGE LEARNING
FINAL EXAMINATION TEST 2026 FULL
ANSWERS GRADED A+
⩥ BAX family of proteins. Answer: pro-apoptotic and thus initiate
apoptosis
⩥ Proto-oncogenes. Answer: genes that encode for transcription factors
that stimulate the cell cycle or increase expression or production of
genes that stimulate cell division or growth. They are critical for normal
cellular growth and division, but when they are not needed in normal
cells, as in the case of quiescence, their expression is repressed. In
cancer cells, proto-oncogenes become altered so that they no longer
respond to their regulation signal
⩥ oncogenes. Answer: Only one allele of a proto-oncogene needs to be
expressed wrongly to cause cancer, meaning that oncogenes possess a
dominant cancer phenotype.
⩥ Tumor-suppressor genes. Answer: make products that either help to
control the regulation of cell cycle checkpoints or are involved in the
initiation of apoptosis. When these genes are mutated, the cells are either
unable to respond normally to the checkpoints or are unable to undergo
apoptosis in response to DNA damage
, ⩥ ras gene families. Answer: some of the most commonly mutated genes
in human cancers, as they are mutated in more than 30% of all tumors.
function at the beginning of several signaling cascades that transmit
signals from growth factors at the membrane to the nucleus to activate
transcription factors that induce cell division
⩥ Ras signal transduction. Answer: as proteins interact with a GDP-GTP
nucleotide exchange factor, and their activation depends on whether they
are bound to GTP (on) or GDP (off). When a growth factor binds to the
membrane, the GDP-GTP exchange factor prompts Ras to lose its GDP
in exchange for GTP, thus activating it to induce a phosphorylation
signaling cascade that culminates in the activation of transcription
factors. After Ras has mediated this signaling cascade, it hydrolyzes
GTP back to GDP to become inactivated. Ras mutations that prevent this
hydrolysis back to GDP cause the protein to stay frozen in an "on" state,
thus continually inducing the signaling cascades that prompt the cell to
grow and divide.
⩥ TP53 gene. Answer: encodes for the p53 transcription factor-
esponsible for the control of transcription of more than 50 different
genes. Bound to MDM2
⩥ Metastasis. Answer: ability of abnormal cells to disengage from the
primary tumor, travel through the bloodstream or lymph system to other
sites, and to form secondary tumors at those sites
FINAL EXAMINATION TEST 2026 FULL
ANSWERS GRADED A+
⩥ BAX family of proteins. Answer: pro-apoptotic and thus initiate
apoptosis
⩥ Proto-oncogenes. Answer: genes that encode for transcription factors
that stimulate the cell cycle or increase expression or production of
genes that stimulate cell division or growth. They are critical for normal
cellular growth and division, but when they are not needed in normal
cells, as in the case of quiescence, their expression is repressed. In
cancer cells, proto-oncogenes become altered so that they no longer
respond to their regulation signal
⩥ oncogenes. Answer: Only one allele of a proto-oncogene needs to be
expressed wrongly to cause cancer, meaning that oncogenes possess a
dominant cancer phenotype.
⩥ Tumor-suppressor genes. Answer: make products that either help to
control the regulation of cell cycle checkpoints or are involved in the
initiation of apoptosis. When these genes are mutated, the cells are either
unable to respond normally to the checkpoints or are unable to undergo
apoptosis in response to DNA damage
, ⩥ ras gene families. Answer: some of the most commonly mutated genes
in human cancers, as they are mutated in more than 30% of all tumors.
function at the beginning of several signaling cascades that transmit
signals from growth factors at the membrane to the nucleus to activate
transcription factors that induce cell division
⩥ Ras signal transduction. Answer: as proteins interact with a GDP-GTP
nucleotide exchange factor, and their activation depends on whether they
are bound to GTP (on) or GDP (off). When a growth factor binds to the
membrane, the GDP-GTP exchange factor prompts Ras to lose its GDP
in exchange for GTP, thus activating it to induce a phosphorylation
signaling cascade that culminates in the activation of transcription
factors. After Ras has mediated this signaling cascade, it hydrolyzes
GTP back to GDP to become inactivated. Ras mutations that prevent this
hydrolysis back to GDP cause the protein to stay frozen in an "on" state,
thus continually inducing the signaling cascades that prompt the cell to
grow and divide.
⩥ TP53 gene. Answer: encodes for the p53 transcription factor-
esponsible for the control of transcription of more than 50 different
genes. Bound to MDM2
⩥ Metastasis. Answer: ability of abnormal cells to disengage from the
primary tumor, travel through the bloodstream or lymph system to other
sites, and to form secondary tumors at those sites
