Eukaryotes of Medical Importance

Question 1

What are fungi cell walls made of?

Answer 1

Chitin

Question 2

What do fungal cell membrane contain?

Answer 2

Ergosterol

Question 3

What are the 2 main approaches eukaryotic microbes are classified into?

Answer 3

1. Phenotypic and biochemical
2. Gene Sequencing

Question 4

Define phenotypic and biochemical?

Answer 4

Grouping organisms based on physical and chemical properties

Question 5

Define gene sequencing?

Answer 5

Quantifying relationships by comparing sequences of common genes, such as rRNA

Question 6

State the distinctive features that a fungi possess?

Answer 6

1. Eukaryotic cells with membrane-bound nuclei and organelles.
2. Cell walls composed of chitin.
3. Cell membranes containing ergosterol
4. Chemoorganotrophic nutrition, requiring organic carbon sources.
5. Largely aerobic metabolism.
6. Secretion of enzymes to digest external food sources, enabling them to live on organic waste as saprotrophs.

Question 7

What are the 3 main growth types a fungi exhibit?

Answer 7

1. Filamentous
2. Yeast-like
3. Dimorphic

Question 8

Describe Filamentous?

Answer 8

Thread-like cells that grow by hyphal extension and branching, collectively forming mycelia

Question 9

Describe Yeast-like?

Answer 9

Single, unconnected cells, mostly spherical and larger than bacterial cells, reproducing by budding

Question 10

Describe Dimorphic?

Answer 10

Capable of switching between yeast-like and filamentous forms depending on environmental conditions

Question 11

What are the 3 ecological roles a fungi plays?

Answer 11

1. Symbionts
2. Saprotrophs
3. Pathogens

Question 12

Describe Symbionts?

Answer 12

Form beneficial relationships with other organisms, such as mycorrhizal fungi with plants.

Question 13

Describe Saprotrophs?

Answer 13

Break down organic matter, contributing to nutrient cycling.

Question 14

Describe Pathogens?

Answer 14

Cause diseases in plants, animals, and humans.

Question 15

Importance in Human Affairs - Fungi

Answer 15

1. Food Production
2. Medicine

Question 16

What are the 3 different ways fungal infections can be classified?

Answer 16

1. Superficial (cutaneous)
2. Subcutaneous
3. Systemic

Question 17

Describe Superficial (cutaneous)?
State an example?

Answer 17

Affecting hair, skin, and nails
Athlete’s foot caused by Trichophyton species

Question 18

Describe Subcutaneous?
State an example?

Answer 18

Affecting dermis, subcutaneous tissue, and bone
Sporotrichosis caused by Sporothrix species

Question 19

Describe Systemic?
State an example?

Answer 19

Affecting the entire body
Cryptococcus neoformans infections in immunocompromised individuals

Question 20

What are the various nutritional strategies protists exhibit?

Answer 20

Some are photosynthetic
Some are heterotrophic
Some are mixotrophic

Question 21

Define heterotrophic?

Answer 21

Obtaining nutrients by ingesting other organisms or organic matter

Question 22

Define mixotrophic?

Answer 22

Capable of both photosynthesis and heterotrophy

Question 23

The 3 reproductive methods that protists exhibits?

Answer 23

1. Asexual reproduction through binary fission or multiple fission.
2. Sexual reproduction in some species.
3. Complex life cycles involving multiple stages, especially in parasitic protists.

Question 24

Habitats of protists? (3)

Answer 24

1. Aquatic habitats (freshwater and marine)
2. Soil
3. As symbionts or parasites in other organisms

Question 25

What are the 5 human diseases (Protists)?

Answer 25

1. Entamoeba histolytica 2. Giardia Duodenalis 3. Plasmodium Species ( Malaria) 4. Trypanosoma Cruzi (Chagas Disease) 5.

Question 26

Define Entamoeba histolytica?

Answer 26

1. Causes severe dysentery 2. Has trophozoite (active) and cyst (dormant) stages 3. Transmitted by the faecal-oral route 4. Can be differentiated from the non-pathogenic Entamoeba disappear using PCR

Question 27

Define Giardia Duodenalis ?

Answer 27

1. Causes severe diarrhea and malabsorption. 2. Also has trophozoite and cyst stages. 3. Transmitted by the fecal-oral route. 4. Attaches to the intestinal epithelium.

Question 28

Define Plasmodium Species ( Malaria) ?

Answer 28

1. Intracellular infection of red blood cells. 2. Transmitted by Anopheles mosquito species. 3. Present in South America, Africa, and Asia. 4. Global burden: 249 million reported cases and 608,000 estimated deaths in 2022. 5. 94% of cases and 95% of deaths occur in the WHO African region 6. Children under 5 are particularly vulnerable, accounting for 78% of all deaths in the WHO African region.

Question 29

Define Trypanosoma Cruzi (Chagas Disease) ?

Answer 29

1. Causes chronic infection leading to sudden cardiac failure after about 30 years. 2. Transmitted primarily by the Triatomine bug. 3. Symptoms include mild flu-like symptoms in the acute stage and heart failure or digestive problems in the chronic stage. 4. Can also be transmitted orally, sexually, through blood or organ donation, congenitally, or in laboratory accidents

Question 30

Define Trichomonas Vaginalis ?

Answer 30

1. Sexually transmitted infection. 2. 156 million new cases reported in 2020. 3. Can affect birth outcomes and increase the risk of HIV acquisition. 4. Often asymptomatic in males, but can cause urethritis in about 10% of cases.