MCB 3020 EXAM 6 WITH QUESTIONS
AND ANSWERS 2026/2027 100%
CORRECT
What shapes the development of the microbiome? - ANSWER>Shaped by an intimate contact with natural
environments.
How many microorganisms populate the skin? - ANSWER>Populated by 10¹²-10¹³ microorganisms.
What types of bacteria are found on the skin? - ANSWER>Aerobes, anaerobes, and facultative bacteria.
Why is the skin difficult to colonize? - ANSWER>The skin is difficult to colonize because of different secretions.
How do secretions from oil and sweat glands affect skin colonization? - ANSWER>Secretion of organic acids by oil
and sweat glands creates an acidic pH (pH 4-6).
, hat are characteristics of epidermal secretions? - ANSWER>Epidermal secretions are high in salt.
How does water activity affect microbial growth on skin? - ANSWER>Epidermal secretions are low in water activity.
What antimicrobial enzymes are found in epidermal secretions? - ANSWER>Contain enzymes (lysozymes - degrade
bacterial peptidoglycan).
What is the general composition of skin microbiota? - ANSWER>Mostly Gram-positive bacteria.
Why are Gram-positive bacteria common on the skin? - ANSWER>More resistant to salt and dryness.
Which skin regions are considered moister areas? - ANSWER>Scalp, ears, armpits, genital, and anal areas.
What microbes commonly colonize moister skin areas? - ANSWER>Corynebacterium species and Staphylococcus
epidermidis.
How does skin microbiota benefit us by affecting epithelial cells? - ANSWER>Prompting the expression of epithelial
cell tight-junction proteins.
AND ANSWERS 2026/2027 100%
CORRECT
What shapes the development of the microbiome? - ANSWER>Shaped by an intimate contact with natural
environments.
How many microorganisms populate the skin? - ANSWER>Populated by 10¹²-10¹³ microorganisms.
What types of bacteria are found on the skin? - ANSWER>Aerobes, anaerobes, and facultative bacteria.
Why is the skin difficult to colonize? - ANSWER>The skin is difficult to colonize because of different secretions.
How do secretions from oil and sweat glands affect skin colonization? - ANSWER>Secretion of organic acids by oil
and sweat glands creates an acidic pH (pH 4-6).
, hat are characteristics of epidermal secretions? - ANSWER>Epidermal secretions are high in salt.
How does water activity affect microbial growth on skin? - ANSWER>Epidermal secretions are low in water activity.
What antimicrobial enzymes are found in epidermal secretions? - ANSWER>Contain enzymes (lysozymes - degrade
bacterial peptidoglycan).
What is the general composition of skin microbiota? - ANSWER>Mostly Gram-positive bacteria.
Why are Gram-positive bacteria common on the skin? - ANSWER>More resistant to salt and dryness.
Which skin regions are considered moister areas? - ANSWER>Scalp, ears, armpits, genital, and anal areas.
What microbes commonly colonize moister skin areas? - ANSWER>Corynebacterium species and Staphylococcus
epidermidis.
How does skin microbiota benefit us by affecting epithelial cells? - ANSWER>Prompting the expression of epithelial
cell tight-junction proteins.
