trials study

Question 1

what is homeostasis?

Answer 1

maintaining relatively stable internal conditions within the body

Question 2

what is the average temp of human body?

Answer 2

37 degrees

Question 3

process of punctuated equilibrium?

Answer 3

fluctuating rates of evolution–> marked by periods

Question 4

feedback mechanism

Answer 4

heat: stimulus–> receptor–> control centre (hypothalamus) –> effector (shivering, sweating) –> temp decrease/increase

Question 5

first line defence barrier:

Answer 5

skin, mucus

Question 6

how does punctuated equilibrium differ from Darwin’s process?

Answer 6

occurring intermittently, not a gradual change (sometimes rapid or slow periods)

Question 7

what did Sutton, Boveri and Morgan do?

Answer 7

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

Question 8

watson and crick?

Answer 8

DNA shape–> double helix and nitrogenous bases

Question 9

which pathogen is used to transfer desirable gene?

Answer 9

bacteria share their plasmids

Question 10

transgenic species?

Answer 10

DNA from certain organism is inserted into another organism for certain desirable trait

Question 11

natural selection eg:

Answer 11

antibiotic resistance: bacteria

insects develop resistance to DDT

Question 12

artificial selection:

Answer 12

cows getting bigger

Question 13

process to produce transgenic species eg:

Answer 13

1. The desirable gene coding for bovine growth hormone is identified on the chromosome and remove using specialised restriction enzymes.
2. Regulatory promoter sequences are added which allow the isolated gene to function and be expressed.
3. Multiple copies of the gene are made using polymerase chain reaction (PCR) technique. Alternatively you can clone using a bacterial plasmid.
4. The gene is inserted into the egg cell of the salmon using microinjection, a gene gun or viral vector.
5. The gene for BGH is expressed in the salmon offspring.

Question 14

characteristics of a: prion

Answer 14

• smallest pathogen, protein which causes disease, non living and don’t have DNA
• infect by distorting shape of healthy protein
• usually found in brain

Question 15

characteristics of a: virus

Answer 15

• non/living
• DNA encased in protein
• non cellular
• very small, must reproduce by hijacking host cell and injecting its DNA

Question 16

characteristics of a: fungus

Answer 16

• both uni/multi-celled eukaryotes
• have cell wall/membrane
• tiny: yeast to large:mushrooms
• reproduces by spores, a/sexual reproduction

Question 17

characteristics of a: bacteria

Answer 17

• single-celled prokaryote
• have cell wall too
• binary fission and asexual reproduction

Question 18

characteristics of a: macroparasite

Answer 18

• seen with naked eye
• multicelled Eurkaryotic
• ENDOparisite: living inside the body
• ECTOparasite: external, suck blood
• may be vector too

Question 19

eg. and method of contraction/ treatment: fungus

Answer 19

thrush, tinea, mould,ringworm

contract by: contact, contaminated water
treat: antifungal medicine/creams

Question 20

eg. and method of contraction/ treatment: virus

Answer 20

eg: HIV AIDS, measles, SARS

contraction: bodily fluids, cough/sneeze
antiviral drugs, vaccines, DIFFICULT THO- KILL HOST CELL TOO

Question 21

eg. and method of contraction/ treatment: bacteria

Answer 21

contract by: contaminated food, airbourne, bodily fluid

eg: Salmonella, Tuberculosis
treatment: antibiotics, bacteriophages, hygiene

Question 22

eg. and method of contraction/ treatment: macroparisite

Answer 22

eg: ENDO: tapeworm
ECTO: fleas, ticks, lice

treatment: antiparasite drugs, surgery

Question 23

what is validity?

Answer 23

if it tests the aim properly, all factors controlled to test one factor, suitable equipment used

Question 24

what is reliability?

Answer 24

whether results are consistent, repeating, using large sample size

Question 25

what is the difference between divergent and convergent evolution?

Answer 25

divergent: evolved from common ancestor are becomes more and more different
convergent: due to natural selection/environmental pressures = unrelated species develop similar characteristics

Question 26

eg of convergent/divergent evolution:

Answer 26

divergent: Darwin’s finches
convergent: Shark (fish) and dolphin (mammal), adapted to highly viscous waters/ streamlined body and fins to propel in water

Question 27

where does mutation effect?

Answer 27

DNA replication process

Question 28

difference between polypeptide, protein and amino acids:

Answer 28

amino acids = make polypeptide
polypeptide is joined by peptide bonds = no structure
protein= polypeptide folded into particular structure

Question 29

what is colour blindness?

Answer 29

lack of photopsins in cones/ irregular functioning

red/green: can’t distinguish red/green from absence of cone

Question 30

myopia and how to fix:

Answer 30

short sight:

eyeball is too long, concave lens to diverge light

Question 31

hyperopia and how to fix:

Answer 31

long sight:

eye ball is too short/round, convex lens to converge light

Question 32

cataracts: cause, appearance, effect, cure:

Answer 32

injury/trauma to eye, aging

cloudy, yellowish

visual clarity fades, go blind if untreated

intraocular lens, easy surgery

Question 33

eustachian tube:

Answer 33

connects throat to middle ear, equalize air pressure with outside/middle ear

Question 34

sound shadow significance:

Answer 34

from difference in sound volume and time arriving, work out direction

Question 35

parts of hearing aid/energy transfer:

Answer 35

microphone, speaker, amplifier

sound –> electrical –> amplified sound

Question 36

parts of cochlear implant/energy transfer:

Answer 36

transmitter, microphone, processor, implant

sound–> electrical signal

Question 37

health:

Answer 37

complete physical, social and mental well being

Question 38

genes: how does it assist maintaining health?

Answer 38

ensuring correct proteins are made

Question 39

mitosis:: how does it assist maintaining health?

Answer 39

repair tissue, growth

Question 40

cell differentiation/ specialisation: how does it assist maintaining health?

Answer 40

differentiation: mature cells have specific function,
specialisation: genes necessary will switch on

Question 41

why is personal hygiene important?

Answer 41

body openings are clean, pathogens entering are reduced, reduce transmission of disease

Question 42

why clean water and food important?

Answer 42

food and water are easiest way for pathogens to enter the body, reducing risk of infection

water allows pathogens to multiply easily

Question 43

water treatment eg:

Answer 43

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

Question 44

Pasteur’s cont:

Answer 44

“germ theory”
disproved spontaneous generation–> swan neck flasks, microbes from air

mircoorganisms cause decay

Question 45

Koch’s cont:

Answer 45

particular microbes will cause particular disease (cholera, tuberculosis)

anthrax in sheep/ vaccine

Question 46

Koch’s postulates:

Answer 46

• 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

Question 47

infectious disease eg: cause, tranmission, host response, major symptoms, treatment, prevention, control

Answer 47

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,

Question 48

how antibiotics work:

Answer 48

in cell of bacteria: stop forming cell wall, destroy cell membrane, stop protein synthesis