Microorganisms- Mas'ood Adam Flashcards Preview

Grade 11-C Study Group > Microorganisms- Mas'ood Adam > Flashcards

Flashcards in Microorganisms- Mas'ood Adam Deck (12)
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1
Q

What are disease causing microorganisms called?

A

Pathogens

2
Q

Describe the basic structure of a virus

A

Very small (20nm-450nm)
Consist of nucleic acid surrounded by a protein capsule
Contain DNA or RNA

3
Q

Describe the general characteristics of viruses

A

They are acellular
Known as obligate intracellular parasites
Are host specific (some are tissue-specific)
Are pathogenic
Convert genetic material (DNA or RNA) into viral nucleic acids for reproduction

4
Q

Basic structure of bacteria

A
Unicellular 
Prokaryotic
Bacterium cell surrounded by a cell wall
Cell wall is surrounded by a slime layer or capsule 
Plasma membrane encloses the cytoplasm
DNA found in the nucleoid
5
Q

Shapes of bacteria

A

Rod-shaped (bacillus)
Spherical/round (coccus)
Spiral-shaped (spirillum)
Comma-shaped (vibrio)

6
Q

Describe the general characteristics of bacteria

A

Unicellular
Prokaryotic
Some are autotrophic while a majority of bacteria is heterotrophic
Reproduction occurs asexually by binary fission

7
Q

Describe the basic structure of protists

A

Uni- or multicellular
Algae contains chloroplasts
Protozoa ingest food by phagocytosis

8
Q

Describe the general characteristics of protists

A

Eukaryotic
Algae are autotrophic
Reproduction mostly asexual by binary fission. However, some algae reproduce sexually
Most protists are aquatic

9
Q

Describe the basic structure of fungi

A

Some are macroscopic (mushrooms) and others microscopic (yeasts)
Cell walls made of chitin
Yeasts are unicellular and reproduce asexually by budding
Multicellular fungi consists of branched mass of filaments called hyphae which together form the mycelium

10
Q

Describe the role of microorganisms as producers

A

Autotrophic bacteria and protists (algae) produce their own organic nutrients
These organisms form the first link (producers)
Energy is stored in carbohydrates and is available to the next tropic level

11
Q

Describe the role of microorganisms as decomposers

A

Decomposition bacteria, saprophytic fungi and protists break down dead organic matter
water, carbon dioxide, ammonia and heat energy are released during decomposition
Elements are recycled in the environment and are available for uptake by plants

12
Q

Describe the role of microorganisms in the nitrogen cycle

A

Free-living soil bacteria and nodule bacteria convert free nitrogen into nitrates
The ammonia that is released is processed by the nitrifying bacteria into nitrates and nitrites
Ammonia and nitrates are converted into free nitrogen in the atmosphere by denitrifying bacteria