Artifical, speciation, pathogen Flashcards
What is aritfical breeding
When a populations gene pool is altered by humans alterning the breeding behaviour of aniamls and plants to select for a desired trait.
Whats the difference between natural selection and artifical selection
Natural selection has the selection pressure that affects the gene pool occuring naturally whereas artifical slection, the selection pressure is human induced. There is a desired trait that humans are intentionally selecting or removing from the population.
What can happen in some selective corsses
Can cause dramatic genetic changes such as polyploidy ( especially in plants)
What is the process of artifical selection
- Individuals in a population vary genetically, leading to phenotypic differences
- The phenotypic traits can be passed on from parents to offspring
- A desirable trait is selected by humans who alter the breedig population
- After selection, the breeding population repoduced by natural forces or human induced breeding , which will be repeated over many generations, showing a higher favouble gene expression each time.
Variation-heritability-intervention-breeding
How does artifical selecting make it bad
Repeated inbreeding increases the amount of homozygous alleles in the offspring, which is negative as this can lead to the expression of deleteioud recessive alleles
How does aritifcal selection affect genetiic diveristy
It reduces genetic diverisy, this is as
We moved from selective breeding to genetic modification overtime true or false
True
What are antimicrobials
Antimicrobials are agents that are used to prevent and treat infections in humans, aniamls and plants.
what is disinefectants, antiseptics, antibiotics, antifungal, antiviral
- Disinfectants- substances that are applied to non-living surfaces to kill or slow the growth of microorganisms
- Antiseptics-substances that are applied to living tissue to kill or slow the growth of microorganisms
- Antibiotics-Kill bacteria
- Antivirals-Kill virus
- Antifungal-Kill fungi
What is antimicrobial resistance
Antimicrobial resistance is the ability of a pathogen to survive exposure to an antimicrobial agent
How does antibiotic resistance occur
Antibiotic resistance bacteria come from natural selection, where the antibiotics is the enviromental selction pressure.
The bacteria that is resistant to an antibiotics have selective advantage via a mutation, which means it can continue to live and replicate within an orgnaism- causing it have a increased allele frequncey for antibiotic reistancE AND the bacteria without the gene is killed off by the drug
The bacteria with antibiotic reistant can also exchange genetic material with other bacteria through bacterial conjugation. Soreading the antibiotic reistant gene.
What ways can bacterial reistance mehcanisms
1.Pumping out the antibiotics out of the bacterial cell
2.Inactivating the antbiotic to reduce its effect
3.decreadsing cell wall perimiability
4.Changing the shape of the protien targeted by the antibiotic
What factors influence the formation of antibitoic reistant bacteria
- Non-compliance when taking antibiotics- some individuals dont complete their course of antibtoics, so pathogenic bacteria can still reproduce and increase the chance of a mutation occuring with anitbiotic reistance
- Innapropriate use of antibiotics- when antibiotics are unessarily prescribed for a viral infection, which may select for antibitoic reistence in** normal flora.**
3.Widespread use of antibitoics- increased use of antibiotics can increase the probability that an individual prescribned with antibiiotics will have an antibitoic reistant bacteria. WHich is selected by natural selction.
How can antivrial drug reistance occur
Through antigenic shift and antigenic drift
When surface antigens of virus undergo changes, what does that allow the virus to do
- Avoid detection by the immunological memory
- Be unaffected by existing medications
What is antigenic shift
When multiple different strains of a virus combine when coinfecting the same host cell to form a new subtype of virys through virus recombination
can cause epidemic or pandemic
What is antigenic drift
When a mutation accumulate and occur gradually and therefore forms a new subtype of virus.
What are the two types of speciation
Allopatric and sympatric
What is speciation?
The process in which populations genetically diverge until they become distinct species.
What does viable and fertile mean
Viable means ability to survive
Fertile means able to reproduce
What are two isolating sub cateogry of isolating mechanism
Pre reproductive isolating mechanisms
and post reproductive isolating mechanisms
What are the types of pre reproductive isolating mechanisms and explain
Geographical: Indivudals are seperated by a barrier
Temporal: the time of day or year the individual is ready to mate may differ.
Behaviroul: types of mating behaviours, such as mating calls,rituals,dances may differ between individuals
Ecological: Individuals may inhibit different ecological niches or habitats that makes it unlikely to interact and breed.
Structural: the physical characteristics of the inidviduals, physiccally prevent them from breeding.
What are the types of post reproductive isolating mechanisms and explain
Gamete mortality: the sperm is unable to penetrate the ovum for fertilisation
Zygote mortality: After fertilisation, a zygote may be formed but will not survive
Hybrid sterility: A viable offspring may be formed and may survive, however will not be fertile
It would be expected that as the number of ecological niches increases, the number of new species would
increase
