Five Kingdoms Flashcards
What are Monera mostly composed of?
Bacteria
What kingdom does bacteria belong to?
Monera
What type of organisms are bacteria?
Unicellular organisms
What are bacteria also classified as? Why?
Prokaryotes, as they have no membrane bound nucleus or membrane bound cell organelles.
What are the different shapes that bacteria are classified into? Give examples of each.
- Spherical (cocci) e.g. pneumonia
- Rod (bacillus) e.g. anthrax, E.coli
- Spiral (spirillum) e.g. syphilis
Draw the two diagrams on edmodo of bacterial structures
now
How do bacteria reproduce?
asexually
What is the method used by a bacteria to reproduce called?
Binary Fission
How does binary fission occur?
The chromosome attaches to the plasma membrane and the DNA is replicated. Then the cell elongates and the two chromosomes separate. The cell wall grows to divide the cell in two. Two identical daughter cells are formed.
Draw binary fission in action.
now
How is DNA replicated during binary fission?
The chromosome attaches to the plasma membrane and the DNA is replicated. Then the cell elongates and the two chromosomes separate.
What does bacteria reproducing asexually cause?
Their offspring are genetically identical
What would one expect to occur because of bacteria reproducing asexually?
As there is little recombination of genetic material in this method of reproduction one would expect that bacteria would be slow to evolve.
How long is the lifecycle of bacteria?
Bacteria has a very short lifecycle (some can reproduce every 20 minutes).
Do new mutations spread fast in bacteria? What does this cause?
New mutations can spread very quickly. This is how bacteria evolve resistance to new antibiotics.
Give one way that bacteria can withstand unfavourable conditions.
Some bacteria can withstand unfavourable conditions by producing endospores.
How are endospores formed?
When the bacterial chromosome replicates. One of the new strands becomes enclosed in a tough-walled capsule called an endospore. The parent cell then breaks down and the endospore remains dormant. When conditions are favourable the spores absorb water, break their walls and reproduce by binary fission.
What is an endospore
A tough-walled capsule that encloses one of the new strands of bacterial chromosome
What are the parts of bacterial cells?
Cell wall, cytoplasm, nuclear material, capule, flagella, plasmid*. sometimes present
What is the function of the bacterial cell wall?
Gives shape and structure
What is the function of the bacterial cell cytoplasm?
Contains ribosomes and storage granules but no mitochondria or chloroplasts
What is the function of the bacterial cell nuclear material?
Single chromosome of DNA
What is the function of the bacterial cell capsule?
Protection
What is the function of the bacterial cell flagella?
Movement
What is the function of the bacterial cell plasmid?
Circular piece of DNA containing few genes for drug resistance
Autotrophic
Organisms which make their own food
Heterotrophic
Organisms which take in food made by other organisms
Name two types of autotrophic bacteria
Photosynthetic bacteria and chemosynthetic bacteria
What do photosynthetic bacteria do and give an example of them
Use light energy to make food e.g. purple sulphur bacteria
What do chemosynthetic bacteria do and give an example of them
Use energy from chemical reactions to make food e.g. nitrifying bacteria that convert ammonia to nitrates in the nitrogen cycle
Name two types of heterotrophic bacteria
Saprophytic bacteria and parasitic bacteria
What do saprophytic bacteria do and give an example of them
Live off dead organic matter e.g. bacteria of decay in the soil
What do parasitic bacteria do and give an example of them
Take food from live host. Some cause diseases.
e.g. Bacillus anthracis causes anthrax
What must bacteria have for the maximum growth rate?
For the maximum growth rate bacteria must have access to a food source and the conditions of their environment must be monitored closely
What factors in too much or little an amount will slow down the growth of bacteria?
Temperature, oxygen concentration, pH, external solute concentration, pressure
What is the ideal temperature for bacteria and what can happen if the temp. gets too high or too low?
Most bacteria grow well between 20 degrees celsius and thirty degrees celsius. Some can tolerate much higher temperatures without their enzymes becoming denatured. Low temperatures slow down the rate of reaction of enzymes resulting in slower growth.
What happens if a bacterium is placed in an unsuitable pH?
It’s enzymes will become denatured
Do bacteria require oxygen?
Aerobic bacteria require oxygen for respiration e.g. streptococcus. Anaerobic bacteria do not require oxygen to respire e.g. Facultative anaerobes such as E.Coli