trials study Flashcards
what is homeostasis?
maintaining relatively stable internal conditions within the body
what is the average temp of human body?
37 degrees
process of punctuated equilibrium?
fluctuating rates of evolution–> marked by periods
feedback mechanism
heat: stimulus–> receptor–> control centre (hypothalamus) –> effector (shivering, sweating) –> temp decrease/increase
first line defence barrier:
skin, mucus
how does punctuated equilibrium differ from Darwin’s process?
occurring intermittently, not a gradual change (sometimes rapid or slow periods)
what did Sutton, Boveri and Morgan do?
Morgan: fruit flies –> sex-linked chromosomes, eye colour on X/Y chromosome
Sutton: grasshopper–> random assortment of genes in meiosis
Boveri: urchin –> meiosis, complete set of chromosomes for normal growth, genes on chromosomes
watson and crick?
DNA shape–> double helix and nitrogenous bases
which pathogen is used to transfer desirable gene?
bacteria share their plasmids
transgenic species?
DNA from certain organism is inserted into another organism for certain desirable trait
natural selection eg:
antibiotic resistance: bacteria
insects develop resistance to DDT
artificial selection:
cows getting bigger
process to produce transgenic species eg:
- The desirable gene coding for bovine growth hormone is identified on the chromosome and remove using specialised restriction enzymes.
- Regulatory promoter sequences are added which allow the isolated gene to function and be expressed.
- Multiple copies of the gene are made using polymerase chain reaction (PCR) technique. Alternatively you can clone using a bacterial plasmid.
- The gene is inserted into the egg cell of the salmon using microinjection, a gene gun or viral vector.
- The gene for BGH is expressed in the salmon offspring.
characteristics of a: prion
- smallest pathogen, protein which causes disease, non living and don’t have DNA
- infect by distorting shape of healthy protein
- usually found in brain
characteristics of a: virus
- non/living
- DNA encased in protein
- non cellular
- very small, must reproduce by hijacking host cell and injecting its DNA
characteristics of a: fungus
- both uni/multi-celled eukaryotes
- have cell wall/membrane
- tiny: yeast to large:mushrooms
- reproduces by spores, a/sexual reproduction
characteristics of a: bacteria
- single-celled prokaryote
- have cell wall too
- binary fission and asexual reproduction
characteristics of a: macroparasite
- seen with naked eye
- multicelled Eurkaryotic
- ENDOparisite: living inside the body
- ECTOparasite: external, suck blood
- may be vector too
eg. and method of contraction/ treatment: fungus
thrush, tinea, mould,ringworm
contract by: contact, contaminated water
treat: antifungal medicine/creams
eg. and method of contraction/ treatment: virus
eg: HIV AIDS, measles, SARS
contraction: bodily fluids, cough/sneeze
antiviral drugs, vaccines, DIFFICULT THO- KILL HOST CELL TOO
eg. and method of contraction/ treatment: bacteria
contract by: contaminated food, airbourne, bodily fluid
eg: Salmonella, Tuberculosis
treatment: antibiotics, bacteriophages, hygiene
eg. and method of contraction/ treatment: macroparisite
eg: ENDO: tapeworm
ECTO: fleas, ticks, lice
treatment: antiparasite drugs, surgery
what is validity?
if it tests the aim properly, all factors controlled to test one factor, suitable equipment used
what is reliability?
whether results are consistent, repeating, using large sample size
what is the difference between divergent and convergent evolution?
divergent: evolved from common ancestor are becomes more and more different
convergent: due to natural selection/environmental pressures = unrelated species develop similar characteristics
eg of convergent/divergent evolution:
divergent: Darwin’s finches
convergent: Shark (fish) and dolphin (mammal), adapted to highly viscous waters/ streamlined body and fins to propel in water
where does mutation effect?
DNA replication process
difference between polypeptide, protein and amino acids:
amino acids = make polypeptide
polypeptide is joined by peptide bonds = no structure
protein= polypeptide folded into particular structure
what is colour blindness?
lack of photopsins in cones/ irregular functioning
red/green: can’t distinguish red/green from absence of cone
myopia and how to fix:
short sight:
eyeball is too long, concave lens to diverge light
hyperopia and how to fix:
long sight:
eye ball is too short/round, convex lens to converge light
cataracts: cause, appearance, effect, cure:
injury/trauma to eye, aging
cloudy, yellowish
visual clarity fades, go blind if untreated
intraocular lens, easy surgery
eustachian tube:
connects throat to middle ear, equalize air pressure with outside/middle ear
sound shadow significance:
from difference in sound volume and time arriving, work out direction
parts of hearing aid/energy transfer:
microphone, speaker, amplifier
sound –> electrical –> amplified sound
parts of cochlear implant/energy transfer:
transmitter, microphone, processor, implant
sound–> electrical signal
health:
complete physical, social and mental well being
genes: how does it assist maintaining health?
ensuring correct proteins are made
mitosis:: how does it assist maintaining health?
repair tissue, growth
cell differentiation/ specialisation: how does it assist maintaining health?
differentiation: mature cells have specific function,
specialisation: genes necessary will switch on
why is personal hygiene important?
body openings are clean, pathogens entering are reduced, reduce transmission of disease
why clean water and food important?
food and water are easiest way for pathogens to enter the body, reducing risk of infection
water allows pathogens to multiply easily
water treatment eg:
primary filtration: wire rack–> large particles
coagulation agent: solids clump in water and sink (soil/faeces) sped up by flocculation (spins)
sedimentation: solids removed and drained -> compost
filtration: fine filter trap most small particles (eg. protozoa)
disinfection: chlorine kill virus/bacteria, fluoride added
Pasteur’s cont:
“germ theory”
disproved spontaneous generation–> swan neck flasks, microbes from air
mircoorganisms cause decay
Koch’s cont:
particular microbes will cause particular disease (cholera, tuberculosis)
anthrax in sheep/ vaccine
Koch’s postulates:
- supposed microbe causing disease is present in all sick organisms
- able to be isolated and grown in pure culture
- microbe from pure culture when injected into healthy organism cause disease
- reproduced disease should e identical to original culture
infectious disease eg: cause, tranmission, host response, major symptoms, treatment, prevention, control
Malaria:
“bad air”= Plasmodium (protozoa) carried by Anopheles mosquito, invade red blood cells, cause chills, nausea, fever, vomiting
host response: fever 41deg destroy enzymes
prevention: remove stagnant water/ mosquito nets, fly screen
treatment: quinine, chloro-quinine, anti-malarial drugs
control: draining swamps, insecticides, genetically modified mosquitoes,
how antibiotics work:
in cell of bacteria: stop forming cell wall, destroy cell membrane, stop protein synthesis
