Question 1

Which of the following statements best describes the nutritional mode of all fungi?

Accepted Answer

Fungi are chemoheterotrophs that require organic compounds for both energy and carbon.

Question 2

Which medium is most selective for the growth of pathogenic fungi and why?

Accepted Answer

Mycosel agar because it contains chloramphenicol and cycloheximide to inhibit bacteria and most saprophytic fungi.

Question 3

A yeast cell divides by budding. Sometimes, the buds remain attached, forming branching filaments. What are these filaments called, and what is their role in pathogenesis?

Accepted Answer

Hyphae; they help the yeast invade deeper tissues after colonizing the epithelium.

Question 4

Which of the following best describes the difference between yeasts and molds?

Accepted Answer

Yeasts are unicellular and divide by budding, while molds are multinucleated and filamentous.

Question 5

Which of the following equations correctly represents aerobic cellular respiration in yeasts?

Accepted Answer

$$\mathrm{C_6H_{12}O_6$ + 6O_2 \rightarrow 6CO_2 + 6H_2O + ATP}$$

Question 6

Which of the following best describes the function of Saboraud Dextrose Agar (SDA)?

Accepted Answer

It is a selective medium for fungi due to its high sugar concentration and low pH, which inhibit bacterial growth.

Question 7

A microbiologist wants to stimulate the formation of hyphae, blastoconidia, and chlamydoconidia in Candida albicans. Which medium should they use?

Accepted Answer

Rice Extract Agar

Question 8

Which of the following statements about yeast metabolism is correct?

Accepted Answer

Yeasts are facultative anaerobes and can obtain energy through both aerobic respiration and fermentation.

Question 9

Which of the following best describes blastoconidia (blastospores)?

Accepted Answer

Asexual spores that develop in clusters along the hyphae, often at branching points.

Question 10

A student streaks a plate of Mycosel agar with Candida albicans, Saccharomyces cerevisiae, and Staphylococcus epidermidis. After incubation, which organism(s) would you expect to grow and why?

Accepted Answer

Only Candida albicans, because Mycosel agar inhibits bacteria and most saprophytic fungi.

Question 11

Which of the following best explains why Saboraud Dextrose Agar (SDA) is selective for fungi?

Accepted Answer

It contains a high sugar concentration and low pH, which inhibit most bacteria.

Question 12

Which of the following is a correct description of chlamydoconidia (chlamydospores)?

Accepted Answer

Thick-walled survival spores that may form at the tips of hyphae under certain growth conditions.

Question 13

Which of the following best describes the appearance of yeast colonies on solid media?

Accepted Answer

They appear as smooth, bacterial-like colonies due to their unicellular and microscopic nature.

Question 14

Which of the following best describes the process by which yeasts reproduce?

Accepted Answer

Budding

Question 15

Which of the following statements about the role of hyphae in yeast pathogenesis is correct?

Accepted Answer

Hyphae help yeasts invade deeper tissues after colonizing the epithelium.

Question 16

Which of the following best describes the function of chloramphenicol in Mycosel agar?

Accepted Answer

It inhibits the growth of bacteria by targeting 70S ribosomes.

Question 17

Which of the following is NOT a correct pairing of organism and the medium that best supports its growth?

Accepted Answer

Staphylococcus epidermidis – Mycosel agar

Question 18

Which of the following best describes the metabolic flexibility of yeasts?

Accepted Answer

Yeasts are facultative anaerobes, capable of both aerobic respiration and fermentation.

Question 19

Which of the following best describes the main difference between blastoconidia and chlamydoconidia?

Accepted Answer

Blastoconidia are asexual spores formed in clusters along hyphae, while chlamydoconidia are thick-walled survival spores formed at hyphal tips.

Study Guide: Yeasts and Fungal Growth in Microbiology lab 9

Guida di studio - Domande di pratica

Study guide - Flashcard