The Kingdoms Of Life (Chpt 19, 20, 21, 22) Flashcards
Taxonomy
Classification and identification of living organisms
Classification
Placing organisms into groups based on similar characteristics
Species
A group of organisms capable of interbreeding naturally to produce fertile offspring
Prokaryotic cells
Do not posses a nucleus or membrane bound organelles
Eukaryotic cells
Have a nucleus and membrane bound organelles
Micro-organisms
Small living things
DIAGRAM OF BACTERIA
Shapes of bacteria & examples
Round → pneumonia
Rod → tetanus
Spiral → syphilis
What name is given to bacterial reproduction?
Binary fission
Steps in bacterial reproduction
• DNA replicates
• cell elongates
• DNA moves to each side
• cell splits in two
• two identical daughter cells produced
What causes endospore formation in bacteria?
Unfavourable conditions
Eg drought
Steps in endospore formation (bacteria)
• contents of cell shrinks
• chromosomes replicate
• tough outer coat formed within cell around genetic material
Factors affecting growth rate of bacteria
Temperature
pH
Solute concentration
Oxygen concentration
Antibiotic
Chemicals produced by microorganisms that stop the growth of or kill other microorganisms
What causes antibiotic resistance?
Misuse of antibiotics
Mutations
Pathogenic bacteria
Disease causing bacteria
Beneficial uses of bacteria
• used to make antibiotics
• produce yogurts & cheese
• symbiotic bacteria in gut
Harmful uses of bacteria
• cause animal & plant disease
• cause food decay
GROWTH CURVE OF BACTERIA
Lag phase - adapting to environment
Log phase - rapid growth, abundant resources
Stationary phase - birth rate = death rate
Death phase - decline due to competition
Survival phase - small number survive as spores
Bioprocessing
The use of microorganisms to form useful products
Bioreactor
A container in which living cells or their products are used to make a product
Batch flow production
Growth of cells in a bioreactor over a short period of time, under ideal conditions until all nutrients are used up
Continuous flow production
Growth of cells in a bioreactor where nutrients are added and the end products are removed all the time at a rate that maintains the volume of liquid and number of cells
Features of fungi
• heterotrophic
• eukaryotic
• made up of hyphae
• walls made of chitin (carbonydrate)
What carbohydrate is found in the walls of fungi?
Chitin
Example & explanation of an obligate parasite
Only take food from a live host and require host to reproduce
↳ athletes foot
Example & explanation of a facultative parasite
Can get food from a live or dead host
↳ soft rot
Why are saprophytes important?
They play a role in decomposition
Example of a toxic mushroom
Death cap
Example of an edible mushroom
Field mushroom
DIAGRAM OF RHIZOPUS
In rhizopus, what is the role of the stolon?
Allows for horizontal spreading
In rhizopus, what is the role of the rhizoid?
Anchorage and absorption
In rhizopus, what is the role of the sporangiophore?
Reproduction
Sporulation
Process of making spores
Asexual reproduction in rhizopus (name & explanation)
Sporulation
• sporangium produces spores by mitosis
• haploid spores transported by wind to substrate
↳ occurs more frequently as only one parent present
What causes sexual reproduction in rhizopus?
Happens in adverse conditions e.g. drought
DIAGRAM OF SEXUAL REPRODUCTION IN RHIZOPUS
DIAGRAM OF YEAST
How does yeast reproduce?
Asexually by budding
• parent divides by mitosis, daughter nuclei enters small developing bud on surface
• bud separates to become a new individual
Beneficial uses of fungi
Yeast used to produce alcohol
Mushrooms as a food source
How does yeast respire?
Anaerobically in a process called fermentation
In amoeba, what is the function of the pseudopod?
Extends in direction amoeba wishes to move
Used to engulf & digest prey
What is the role of the contractile vacuole in amoeba?
Osmoregulation
What would happen to amoeba if it did not have a contractile vacuole?
It would expand and burst
DIAGRAM OF AMOEBA
DIAGRAM SHOWING FUNCTION OF CONTRACTILE VACUOLE
State one benefit of parasitic bacteria
Population control
Describe batch processing
Fixed amount of nutrients added at start, bacteria goes through all phases of growth curve, product removed at the end
Give one example of an autotrophic bacteria and one example of a heterotrophic bacteria
A: nitrifying bacteria
H: pneumonia
What term is used to describe reproduction in yeast? Name the type of cell
division involved in this process
Budding
Mitosis
Steps in contractile vacuole - AMOEBA
- Water in by osmosis
- Excess water enters contractile vacuole
- Contractile vacuole swells and touches cell membrane
- Contractile vacuole expels water