Question

14.Provide two examples of microbial adaptations to illustrate their ability to survive under harsh environmental conditions

15.Compare and contrast the structures found in the eukaryotic microbial groups (algae, protozoa and fungi) and explain how to distinguish between these groups

16.Provide examples of how eukaryotic microbes are both friend and foe

17.Explain how the eukaryotic microbes obtain nutrients and how they reproduce

18.Draw the basic structure of a virus and explain three different ways of growing viruses in the laboratory

Answer 1

14. They are classified according to the conditions in which they grow: As thermophiles and hyperthermophiles (organisms growing at high or very high temperatures, respectively), psychrophiles (organisms that grow best at low temperatures), acidophiles and alkaliphiles (organisms optimally adapted to acidic or basic pH values, respectively), barophiles (organisms that grow best under pressure), and halophiles (organisms that require NaCl for growth).

15.

Fungi
Fungi (mushroom, molds, and yeasts) are eukaryotic cells (with a true nucleus). Most fungi are multicellular and their cell wall is composed of chitin. They obtain nutrients by absorbing organic material from their environment (decomposers), through symbiotic relationships with plants (symbionts), or harmful relationships with a host (parasites). They form characteristic filamentous tubes called hyphae that help absorb material. The collection of hyphae is called mycelium. Fungi reproduce by releasing spores.

Protozoa
Protozoa are unicellular aerobic eukaryotes. They have a nucleus, complex organelles, and obtain nourishment by absorption or ingestion through specialized structures. They make up the largest group of organisms in the world in terms of numbers, biomass, and diversity. Their cell walls are made up of cellulose. Protozoa have been traditionally divided based on their mode of locomotion: flagellates produce their own food and use their whip-like structure to propel forward, ciliates have tiny hair that beat to produce movement, amoeboids have false feet or pseudopodia used for feeding and locomotion, and sporozoans are non-motile. They also have different means of nutrition, which groups them as autotrophs or heterotrophs.

Algae
Algae, also called cyanobacteria or blue-green algae, are unicellular or multicellular eukaryotes that obtain nourishment by photosynthesis. They live in water, damp soil, and rocks and produce oxygen and carbohydrates used by other organisms. It is believed that cyanobacteria are the origins of green land plants.

16. The main microorganisms in and on our bodies are protozoa, algae, fungi, bacteria and viruses. Most microorganisms are beneficial, for example, there are microorganisms in our large intestine that synthesise vitamins and allow them to be absorbed into the bloodstream. However, a tiny minority are pathogens (disease-causing agents). These pathogens, often called germs or bugs, are a threat to all life forms.

17. Phototrophic organisms capture light energy from the sun and convert it into chemical energy inside their cells.

Most get their energy from organic molecules such as sugars. This mode of obtaining nutrition is very common among eukaryotes, including humans.

It is the characteristic feature of eukaryotic cell that it reproduces sexually. But, it can also reproduce asexually. Asexual reproduction is often referred to as cell division and it occurs through mitosis. On the other hand, sexual reproduction occurs through meiosis.