VIBS 422 Exam Questions and Answers with Verified Solutions |
Latest 2026 Update
Q: Describe terminal end buds (TEBs) and how TEBs are targeted by EDCs
exposure in causing breast cancers.
Answer:
-Form at the tips of elongating mammary ducts during puberty
-TEBs contain stem cells
Motile, mitogenic, target carcinogens
Q: Role of lymphatic tissue or lymph nodes in breast tissue.
Answer:
-Breast tissue is drained by lymphatic vessels that lead to axillary nodes and
internal mammary nodes
-Lymph nodes along the pathway of drainage screen for bacteria or viruses
-When breast cancer spreads, it spreads often to lymph nodes first
Q: What are the important stages of mammary gland development and include
critical events during those windows?
Answer:
Critical events in Mammary gland development:
-Mammary bud development in the fetus
-Exponential epithelial outgrowth during puberty
-Rapid transition to lactational competency that occurs during late pregnancy
Critical periods which EDCs most effect mammary gland development: gestation,
puberty and pregnancy
Q: List 5 EDCs that could target mammary glands.
Answer:
Atrazine, BPA, Phthalate, dioxin, DDT
Q: Briefly describe how the following EDCs influence breast cancer and
associated endocrine disruptions: Atrazine, Bisphenol A (BPA),
Dibutyl-phthalate, Dioxin, DES, Methoxychlor, DDT, Nonylphenol,
Polybrominated diphenyl (PBDE) ethers, PFOA (Perfluorooctanoic acid).
,Answer:
DES:
Prenatal exposure causes excessive nipple development
Increases mammary tumorigenesis and increases the sensitivity of the mammary
gland to other carcinogens
Synthetic estrogen prescribed in the 1940s-1970s to women, increase breast cancer
risk to 4 generations
BPA:
0 0 Alters TEB development and may cause greater elongation-Ductal beading
represents actively proliferating luminal epithelial cells (hyperplasia). This
hyperplasia is considered a precursor to ductal carcinoma.
BPA induces both an elevated susceptibility to carcinogens and spontaneous
neoplasia. Atrazine:
Causes delays in mammary gland development
Leads to increased mammary gland tumors PFOA: Causes delay in puberty in girls
PBDE:
Causes delay in mammary gland development
Dioxin: Carcinogen that causes adverse effects in mammary glands like having a
"spiked appearance"
Also impairs normal lactation
Q: What are the EDCs that can cause precocious development of the mammary
gland and stimulate mammary gland growth?
Answer:
Nonylphenol, phytoestrogens, DES
Q: What are the EDCs that can cause stunted growth of the mammary gland and
inhibit mammary gland development?
Answer:
PCB, PBB, Perfluorooctanoic acid (PFOA), dioxin
Which EDC causes a "beaded structure" of the mammary gland epithelium in a
monkey model? -
BPA
Q: Which EDC causes a "spiked appearance" of the mammary gland?
, Answer:
Dioxin
Q: Describe/elaborate on Dioxin-mechanism of action
Answer:
Dioxins bind the aryl hydrocarbon receptor (AhR) to induce adverse effects in
development and reproduction, including the mammary glands. Enter the nucleus
attached to AhR. AhR binds to DNA for transcription.
Q: What is the name of the EDC that increased breast cancer in Seveso women?
Answer:
Dioxin. Industrial accident that occurred at a small chemical manufacturing plant
in Milan, Italy
Q: Which EDC inhibits nipple-sheath development?
Answer:
DES
Q: What is the role of adding phthalates to plastics?
Answer:
-causes a reduction in the cohesive intermolecular forces along the polymer chains.
-The chains can move more freely relative to one another, and the stiffness of the
polymer is reduced. Plasticizer to increase flexibility, workability, distensibility
Q: Which phthalates constituted 80% of total phthalates?
Answer:
DEHP, DINP, DIDP
Q: What are phthalates?
Answer:
Widely used industrial compounds known as dialkyl or alkyl aryl esters of
1,2-benzene-dicarboxylic acid.
Q: Mention any 4 phthalate compounds:
Answer:
DMP, DEP, DBP, BBP
Latest 2026 Update
Q: Describe terminal end buds (TEBs) and how TEBs are targeted by EDCs
exposure in causing breast cancers.
Answer:
-Form at the tips of elongating mammary ducts during puberty
-TEBs contain stem cells
Motile, mitogenic, target carcinogens
Q: Role of lymphatic tissue or lymph nodes in breast tissue.
Answer:
-Breast tissue is drained by lymphatic vessels that lead to axillary nodes and
internal mammary nodes
-Lymph nodes along the pathway of drainage screen for bacteria or viruses
-When breast cancer spreads, it spreads often to lymph nodes first
Q: What are the important stages of mammary gland development and include
critical events during those windows?
Answer:
Critical events in Mammary gland development:
-Mammary bud development in the fetus
-Exponential epithelial outgrowth during puberty
-Rapid transition to lactational competency that occurs during late pregnancy
Critical periods which EDCs most effect mammary gland development: gestation,
puberty and pregnancy
Q: List 5 EDCs that could target mammary glands.
Answer:
Atrazine, BPA, Phthalate, dioxin, DDT
Q: Briefly describe how the following EDCs influence breast cancer and
associated endocrine disruptions: Atrazine, Bisphenol A (BPA),
Dibutyl-phthalate, Dioxin, DES, Methoxychlor, DDT, Nonylphenol,
Polybrominated diphenyl (PBDE) ethers, PFOA (Perfluorooctanoic acid).
,Answer:
DES:
Prenatal exposure causes excessive nipple development
Increases mammary tumorigenesis and increases the sensitivity of the mammary
gland to other carcinogens
Synthetic estrogen prescribed in the 1940s-1970s to women, increase breast cancer
risk to 4 generations
BPA:
0 0 Alters TEB development and may cause greater elongation-Ductal beading
represents actively proliferating luminal epithelial cells (hyperplasia). This
hyperplasia is considered a precursor to ductal carcinoma.
BPA induces both an elevated susceptibility to carcinogens and spontaneous
neoplasia. Atrazine:
Causes delays in mammary gland development
Leads to increased mammary gland tumors PFOA: Causes delay in puberty in girls
PBDE:
Causes delay in mammary gland development
Dioxin: Carcinogen that causes adverse effects in mammary glands like having a
"spiked appearance"
Also impairs normal lactation
Q: What are the EDCs that can cause precocious development of the mammary
gland and stimulate mammary gland growth?
Answer:
Nonylphenol, phytoestrogens, DES
Q: What are the EDCs that can cause stunted growth of the mammary gland and
inhibit mammary gland development?
Answer:
PCB, PBB, Perfluorooctanoic acid (PFOA), dioxin
Which EDC causes a "beaded structure" of the mammary gland epithelium in a
monkey model? -
BPA
Q: Which EDC causes a "spiked appearance" of the mammary gland?
, Answer:
Dioxin
Q: Describe/elaborate on Dioxin-mechanism of action
Answer:
Dioxins bind the aryl hydrocarbon receptor (AhR) to induce adverse effects in
development and reproduction, including the mammary glands. Enter the nucleus
attached to AhR. AhR binds to DNA for transcription.
Q: What is the name of the EDC that increased breast cancer in Seveso women?
Answer:
Dioxin. Industrial accident that occurred at a small chemical manufacturing plant
in Milan, Italy
Q: Which EDC inhibits nipple-sheath development?
Answer:
DES
Q: What is the role of adding phthalates to plastics?
Answer:
-causes a reduction in the cohesive intermolecular forces along the polymer chains.
-The chains can move more freely relative to one another, and the stiffness of the
polymer is reduced. Plasticizer to increase flexibility, workability, distensibility
Q: Which phthalates constituted 80% of total phthalates?
Answer:
DEHP, DINP, DIDP
Q: What are phthalates?
Answer:
Widely used industrial compounds known as dialkyl or alkyl aryl esters of
1,2-benzene-dicarboxylic acid.
Q: Mention any 4 phthalate compounds:
Answer:
DMP, DEP, DBP, BBP
