BIOL 319 EXAM 1 (COHN) TAMU
UPDATED TEST QUESTIONS WITH
CORRECT SOLUTIONS 2026/2027 LATEST
UPDATE
How are new keratinocytes produced? - ✔✔✔ANSWERKeratinocyte
stem cells undergo mitosis in the deepest layer of the epidermis. As new
cells form, they push older cells to the surface where they slough off
keratinization - ✔✔✔ANSWERthe cells eventually die and produce
an outer layer of dead, hard cells that resists abrasion and forms a
permeability barrier
strata of the epidermis - ✔✔✔ANSWER1. stratum basale
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, 2. stratum spinosum
3. stratum granulosum
4. stratum lucidum
5. stratum corneum
1. stratum basale - ✔✔✔ANSWER-deepest portion of the epidermis is a
single layer of cuboidal or columnar cells
-epidermis anchored to the basement membrane by hemidesmosomes
-desmosomes hold keratinocytes together
-connections between hemidesmosomes and desmosomes provide
structural strength
-keratinocyte stem cells undergo mitosis every 19 days
2. Stratum Spinosum - ✔✔✔ANSWER-consist of 8-10 layers of many
sided cells
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UPDATED TEST QUESTIONS WITH
CORRECT SOLUTIONS 2026/2027 LATEST
UPDATE
How are new keratinocytes produced? - ✔✔✔ANSWERKeratinocyte
stem cells undergo mitosis in the deepest layer of the epidermis. As new
cells form, they push older cells to the surface where they slough off
keratinization - ✔✔✔ANSWERthe cells eventually die and produce
an outer layer of dead, hard cells that resists abrasion and forms a
permeability barrier
strata of the epidermis - ✔✔✔ANSWER1. stratum basale
1|Page
, 2. stratum spinosum
3. stratum granulosum
4. stratum lucidum
5. stratum corneum
1. stratum basale - ✔✔✔ANSWER-deepest portion of the epidermis is a
single layer of cuboidal or columnar cells
-epidermis anchored to the basement membrane by hemidesmosomes
-desmosomes hold keratinocytes together
-connections between hemidesmosomes and desmosomes provide
structural strength
-keratinocyte stem cells undergo mitosis every 19 days
2. Stratum Spinosum - ✔✔✔ANSWER-consist of 8-10 layers of many
sided cells
2|Page
