BIO 109 - Exam 2 2024/2025 Exam All
Answers and Illustrations Given
Keratin (define) - 🧠ANSWER ✔✔a fibrous protein
Dermacidin (What is it) - 🧠ANSWER ✔✔known as proteolysis inducing
factor (PIF), is a protein that is encoded by the DCD gene it is an anti-
microbial peptide secreted by human eccrine sweat glands onto the skin as
apart of the unnate host defense of the immune system
Defensisns (Define) - 🧠ANSWER ✔✔are small cysteine-rich cationic
protein found in both vertebrates and invertebrates. They are, and function
as, host defense peptides. They are acute against bacteria, fungi, and
many enveloped and nonenveloped viruses
Epidermis - 🧠ANSWER ✔✔stratified squamous epithelium
What are the functions of the skin? - 🧠ANSWER ✔✔resistance to trauma
and infection, barrier function, vitamin D synthesis, sensation,
thermoregulation, nonverbal communication.
COPYRIGHT©JOSHCLAY 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY
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STATEMENT. ALL RIGHTS RESERVED
, What are the layers of the epidermis? - 🧠ANSWER ✔✔stratum basale
deepest epidermal layer, stratum spinosum, statym granulosum, stratum
lucidum, statym corneum surface layer
Statum granulosum contains? - 🧠ANSWER ✔✔cells contain dark-staining
kerotohyalin granules
Statum lucudum contains? - 🧠ANSWER ✔✔thin, pale layer found only in
thick skin, keratinocytes packed with clear protein eledin
Eledin - 🧠ANSWER ✔✔is clear intracellular protein which is present in the
stratum lucidum of the skin.
Statum corneym (surface layer) - 🧠ANSWER ✔✔several layers (up to 30)
of dead, scaly, keratinized cells, Resists abrasion, penetration, water loss
Five epidermal cell types? - 🧠ANSWER ✔✔stem cells undifferentiated cells
that give rise to keratinocytes, melanocytes - synthesize pigment melanin
that shields DNA from ultraviolet radiation, tactile cells - associated with
dermal nerve fibers, dentritic cell - macrophages found in stratum
spinosum, keratinocytes great majority of epidermal cells synthesize keratin
Dermis - 🧠ANSWER ✔✔connective tissue layer beneath epidermis.
Areolar and dense irregular connective tissue, well supplied with blood
COPYRIGHT©JOSHCLAY 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY
2
STATEMENT. ALL RIGHTS RESERVED
Answers and Illustrations Given
Keratin (define) - 🧠ANSWER ✔✔a fibrous protein
Dermacidin (What is it) - 🧠ANSWER ✔✔known as proteolysis inducing
factor (PIF), is a protein that is encoded by the DCD gene it is an anti-
microbial peptide secreted by human eccrine sweat glands onto the skin as
apart of the unnate host defense of the immune system
Defensisns (Define) - 🧠ANSWER ✔✔are small cysteine-rich cationic
protein found in both vertebrates and invertebrates. They are, and function
as, host defense peptides. They are acute against bacteria, fungi, and
many enveloped and nonenveloped viruses
Epidermis - 🧠ANSWER ✔✔stratified squamous epithelium
What are the functions of the skin? - 🧠ANSWER ✔✔resistance to trauma
and infection, barrier function, vitamin D synthesis, sensation,
thermoregulation, nonverbal communication.
COPYRIGHT©JOSHCLAY 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY
1
STATEMENT. ALL RIGHTS RESERVED
, What are the layers of the epidermis? - 🧠ANSWER ✔✔stratum basale
deepest epidermal layer, stratum spinosum, statym granulosum, stratum
lucidum, statym corneum surface layer
Statum granulosum contains? - 🧠ANSWER ✔✔cells contain dark-staining
kerotohyalin granules
Statum lucudum contains? - 🧠ANSWER ✔✔thin, pale layer found only in
thick skin, keratinocytes packed with clear protein eledin
Eledin - 🧠ANSWER ✔✔is clear intracellular protein which is present in the
stratum lucidum of the skin.
Statum corneym (surface layer) - 🧠ANSWER ✔✔several layers (up to 30)
of dead, scaly, keratinized cells, Resists abrasion, penetration, water loss
Five epidermal cell types? - 🧠ANSWER ✔✔stem cells undifferentiated cells
that give rise to keratinocytes, melanocytes - synthesize pigment melanin
that shields DNA from ultraviolet radiation, tactile cells - associated with
dermal nerve fibers, dentritic cell - macrophages found in stratum
spinosum, keratinocytes great majority of epidermal cells synthesize keratin
Dermis - 🧠ANSWER ✔✔connective tissue layer beneath epidermis.
Areolar and dense irregular connective tissue, well supplied with blood
COPYRIGHT©JOSHCLAY 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY
2
STATEMENT. ALL RIGHTS RESERVED
