B1.1.2 Flashcards
What are bacteria?
The smallest living organisms that are unicellular and can carry out the seven life processes.
The seven life processes are movement, reproduction, sensitivity, growth, respiration, excretion, and nutrition.
What are examples of prokaryotes?
- Escherichia coli (E. coli)
- Streptococcus bacteria
- Streptomyces bacteria
E. coli causes food poisoning, Streptococcus causes sore throats, and Streptomyces is known for producing the antibiotic streptomycin.
What is the size of many bacteria?
Around 1 μm in size.
Hundreds of thousands of bacteria would fit on a full stop.
What structures do prokaryotic cells contain?
- Cell wall made of peptidoglycan
- Cell membrane
- Genetic material in the cytoplasm
The genetic material is usually a long strand of DNA that is circular.
What is the function of flagella in bacterial cells?
Tail-like structures that allow the cell to move through liquids.
What role do pili play in bacterial cells?
- Enable attachment to structures
- Transfer genetic material between bacteria.
What is the purpose of the slime capsule in bacterial cells?
Protects the bacterium from drying out and poisonous substances, and helps it stick to surfaces.
What is a plasmid?
A circular piece of DNA that stores extra genes, often related to antibiotic resistance.
Fill in the blank: Prokaryotes are _______ organisms without a nucleus.
single-celled
State two similarities between plant and bacterial cells.
- Both have a cell membrane
- Both contain genetic material.
State two differences between plant and bacterial cells.
- Plant cells have a nucleus; bacterial cells do not
- Plant cells have chloroplasts; bacterial cells do not.
What adaptations might a pond-living bacterium have?
Features such as flagella for movement and a slime capsule for protection.
Calculate the number of 2 μm wide Salmonella bacteria that would fit into a gap of 1 mm.
500 bacteria.
Calculate the size, in mm, of a colony of 20,000 Salmonella bacteria lined up end to end.
40 mm.
True or False: All bacterial cells contain the same subcellular structures.
False.
