Bio Quiz 1 Flashcards
What are the two kingdoms of bacteria?
Eubacteria and Archaebacteria
Coccus
Round cell shape
Bacillus
Rod cell shape
Spirillum
Spiral cell shape
Name the characteristics of bacteria. (6)
Abundant, diverse, single-celled, organelles not surrounded by membranes, single chromosome=DNA, reproduce asexually by binary fission.
How big are bacteria?
10 times smaller than a typical eukaryotic cell.
What is the typical structure of bacteria? (5)
a cell wall, cell membrane, ribosomes, DNA in a single strand that forms a ring, flagella (sometimes).
How are bacteria classified? (4)
By shape, reaction to being stained, nutrition, respiration.
What are the different versions of cocci?
Monococci (live on their own), diplococci (pairs), streptococci (linear chains), staphylococci (grape-like structure).
What are the different versions of bacilli?
Monobacilli (single), diplobacilli (paired), streptobacilli (chained).
What are the different ways spiral can exist?
They can only exist as single cells.
What is a gram stain test?
The classification of bacteria based on the reaction to a dye (crystal violet iodine).
What does it mean if a cell keeps the dye.
It is gram positive–they are generally more common and not as harmful or pathogenic.
What does it mean if a cell appears light pink?
It is gram negative–less common and more harmful and pathogenic.
Why do some cells retain the dye?
They have a different cell wall structure. Gram positives don’t have an outer membrane. Gram negatives do.
How do most eubacteria get their energy?
By breaking down organic molecules in their environment. Doing this makes them heterotrophs.
What does it mean to be an autotroph?
They make their own organic compounds. Only some eubacteria are autotrophs.
What are the two types of autotrophs?
Photoautotrophs (use sunlight as their energy source) and Chemoautotrophs (use energy from chemical reactions as their energy source).
What is cyanobacteria?
A IMPORTANT group of blue-green bacteria in the group of photoautotrophs. They are photosynthetic and can use sunlight to make their own food, but lack chloroplasts.
Where are cyanobacteria commonly found?
Freshwater lakes and ponds. They can also be found in salt water, soil, snow, volcanoes, and rocks.
What is a bloom?
A sudden increase in population which indicates that the water is polluted with nitrates and phosphates from agricultural runoff.
How are lichens formed?
When species of cyanobacteria live symbiotically with fungi.
Where do heterotroph bacteria live?
Everywhere.
What are the three types of heterotrophs?
Chemoheterotrophs (most), parasite (absorb nutrients from other species), and saprobes (decompose dead matter).
Where does cellular respiration occur in bacteria?
Within the inner folds of the membrane of the bacteria.
What is it called: bacteria that need oxygen to live?
Aerobes or obligate aerobes if oxygen is absolutely necessary for survival.
What is it called: bacteria that do not need oxygen to live?
Anaerobes or obligate anaerobes if the presence of oxygen kills bacteria.
How do all bacteria reproduce?
Asexually by binary fission.
Explain binary fission.
- Replicate genetic material. 2. Divides into 2 equal-sized daughter cells.
How often can bacteria divide?
Every 15-20 minutes.
What 3 things must be present in order for bacteria to divide?
Food, warmth, and space.
How is mutation rate affected?
By fast reproduction rate. If successful, mutations can evolve if successful.
What is the smaller ring of DNA called?
Plasmid: it contains fewer genes than the chromosome and is not vital.
Explain conjugation (sexual reproduction).
- Two bacteria connect with a protein bridge. 2. The plasmid of one is transferred to the other. 3. The bacterium that receives it becomes more able to adapt to worsening environmental conditions.
When is conjugation used?
When conditions for survival are not ideal.
When do spores form?
When growth conditions become extremely unfavourable.
What are spores?
Structures formed by gram-positive bacteria.
What is an endosphere?
A type of spore made when the bacterium makes a thick wall surrounding its DNA and cytoplasm.
Explain transformation.
- Cell picks up loose, free-flating DNA fragments from their surroundings. 2. Incorporates these DNA fragments into their own.
Explain Horizontal gene transfer.
- Cell picks up new DNA from a different species. 2. Incorporates this DNA into its own.
What are the oldest organisms living on earth?
Bacteria.
What is the oldest group of organisms on Earth?
Archaebacteria.
What do archaebacteria ressemble?
Primitive clusters of molecules. They have no organelles.
What are all life kingdoms descended from?
The ancestors of archaebacteria.
What is the structure of archaebacteria?
Cell wall, cell membrane. They offer protection but are made of different chemicals than eubacteria.
How different are eubacteria and archaebacteria?
More than half their genes are different from eubacteria.
How are archaebacteria grouped?
Into several phyla based on their habitats.
What are anaerobic methanogens?
Archaebacteria that live in oxygen-free places such as the gut of animals that produce methane gas, at the bottom of marshes and swamps, on the ocean floor near the deep sea vents.
What are halophiles?
Archaebacteria, salt-loving, found in salt lakes (dead sea).
What are thermophiles?
Archaebacteria, heat-loving, live in hot and acidic environments (hot springs).
What are psychophiles?
Archaebacteria, cold-loving, live in cold climates (Antarctica, Arctic, cold springs).
What kingdom makes up most of the prokaryotes on Earth?
Kingdom eubacteria.
What are the 6 phylogenetic groups of eubacteria?
-spirochates -chlamydias -gram-positive bacteria -cyanobacteria -proteobacteria