Biology Marathon 2006 (1 Viewer)

[Petinga]

Question: identify data sources, gather process and analyse information from secondary sources to describe one named infectious disease in terms of its:
o cause
o transmission
o host response
o major symptoms
o treatment
o prevention
o control

Infectious Disease: AIDS (Accquired Immunodefiency Syndrome)
Cause: AIDS is caused by the retrovirus HIV (HUman Immunodefiency Virus) which contains RNA rather than DNA. Once it enters the body it targets cells and infilitrates theri DNA with its DNA rsulting in the virus continously being replicated.
Transmission: AIDS is a fatal transmissabl;e disease of the immune system which is non contagouius. It is transmiteed by diect transfer of bodily fluids such as blood and semen. The main methods of trasmission are sex and syrning sharing. Alos through pregnanct to child.
Host response: It target the t helper cells and HIV virus bind to specific receptros on surfaced of t cells destroying them and hence lowering immune system leadingf to indicaul left sussceptilbe to infection and eventual death.
Major symptoms:
- sweats/fever
-diarrhoea
-swollen lymph glands
-fatigue
-dementia and kaposis sarcoma
TReatemnmet: Currnetly no cure against AIDS but there are drug therpaies and test to stem effects of AIDS.
Prevenrtion:
- use condoms and practice monagmy
-do not share needles
women should take antiretroviral drugs if sufferes during pregancnt and use baby formulas for milk
Contrtol: PUblic health programs have reduced number of AIDS cases worldwide and this most effecive control method by warninfg people of cause and transmission methods

 

[Dr_Doom]

That wasn't my question lo.... Where's your question?

 

[Petinga]

Question: Differenciate between homozygous and heterozygous genotypes

Question: Discuss the shift in emphasis form treatemtn and control to prevention and mangaement of disease

Questiuon: Discuss the effectiveness of vaccinations in preventing the spread of once common diseases such as smallpox etc

Question: Identify and describe one disease caused by the imbalance of microflora

 

[Tim035]

I'll take a quick break from trial papers to answer one question.

Imbalance in microflora- Thrush caused by the fungus Candida Albicans is capable of becomming virulent in the mouth, respiratory tract and female genitalia. Fortunatly however, the numbers of this fungal are usually kept non virulent due to competition with friendly microorganisms for resources. However an imbalance in microflora can occur due to an excessive course of antibiotics, malnutrition or by taking the pill. When this occurs Candida Albican's numbers increase and become virulent resulting in the symptons of Thrush appearing in the individual. This is known as oppertunistic infection.

 

[nice]

^^^^^^^^^^^^^^ hmmmmmmm..

do we need to learn about the differences between homozyous and hetrozygous
coz i think we just use it when u do the punnet squares not as in expalinning the differences

 

[nice]

^^^^^^^^^^^^^^ hmmmmmmm..

do we need to learn about the differences between homozyous and hetrozygous
coz i think we just use it when u do the punnet squares not as in expalinning the differences

 

[Dr_Doom]

Question: Differenciate between homozygous and heterozygous genotypes

Homozygous genotypes are also known as purebred. They contain the same alleles on both genes which can be either dominant or recessive.
Heterozygous, also known as hybrid, contain different alleles, one dominant, one recessive.

Question: Discuss the shift in emphasis form treatemtn and control to prevention and mangaement of disease

More emphasis is being put on the prevention and management of diseases to stop them from happening in the first place. Such as public health programs to help people be aware of certain symptoms that may occur in a disease and to demonstrate prevention techniques such as the 'slip slop slap' campaign to help prevent skin cancer.

Questiuon: Discuss the effectiveness of vaccinations in preventing the spread of once common diseases such as smallpox etc

The WHO (world health organisation) had implemented a smallpox vaccination campaign, by using high pressured jet guns which could potentially vacinate thousands of people per hour. The WHO declared the world free of smallpox in 1980.

Question: Identify and describe one disease caused by the imbalance of microflora

Candidiasis (thrush) is when there is an imbalance in the candida albicans, usually too much. This is caued through antibiotics, contraceptive pill or unhygenic methods of wiping. Usually affects women, and anti-funal creams can regulate the balance of microflora.

Question: Show the phenotypes and genotypes of a cross between a homozygous Tall, Round plant TR and a homozygous Short, Wrinkled plant tr. Show all working.

 

[simplistic]

Question: Discuss the shift in emphasis form treatemtn and control to prevention and mangaement of disease

Questiuon: Discuss the effectiveness of vaccinations in preventing the spread of once common diseases such as smallpox etc

Question: Identify and describe one disease caused by the imbalance of microflora

ok
shift ...
priorly drugs were used to treat syptoms
chemicals were used to treat non infectious diseases eg chemotherapy for cancer
in the 1940 and 50s anti biotices were very effetcive at treatinf bacterial infections hoverber to day due to growing reistace penicillan and golden staph
anti malraial drugs have not been sucseesful at eradicating malira
in plants fugicides uesd on dieases such as cureingpotato blight
insecticeds ineffective ddt and mosqutos
today more emphais is put on prevention and control
quaratine aim to protect the countires human plant and animal inhabitants from diesaeas
isolatipon preventsa the spread of diseases eg geo isolation helped prevent entry of bird flu
vaccinations has also reduced the incidens of disease such as dipthria and polio and has even eradicated some such as smallpox
public health eduation has increased the peoples aware ness of the spread of microbes eg washing hand after toliet
higher standares of water treatmwnt and sewage help redcue the spread of water boure microbes eg cholrea and typhoid
genetically engineeraing plansta nd animals to carry the reisitant gene eg bt cotton
these practises have shown that there has been a change in the way microbes are combated

small pox
major ppl kille rinthe 1700s 1/3 ppl died
jenner deveopled a vaccine in 1976
hoever it was not until 1960s that who decied to embark ona eradiaction program by immunoazting the whole world
jet injections with high pressure shots made it possib el to vaccinate 1000ppl/hr
by 1980s it was eradicated
diptheria is a bacterial infection whish is both air bourne and transmitted via direc contact
in 1923 a vaccine was made public
by the 1940s and 50s it was redued from a cyclical epdemic to outbreask of low intensity
in the 1960s who embarked ona vaccination program
by the 90s 80% world vaccinate d
it it not presnt in aus but vaccination is still needed as it afftecs 3rd world countries
poli is a viral infection which caues paralysis and in sever caes death
major child killer in the 1900s
it wa snot until 1955 that a vaccination was develped
in the 1980s who begam a eradication program to eradicated poli
today 805 of the wolrd is vacinated however it is still coom ina few countries suchas nigeria
these eg have shown us that vaccination programs once carried oyt effetcively they reduce the spread of diease

candida albican ( a fungus )
dieases -- candidaise
when bacteria are low in numbers this fungus (an oportuinestic microbe) will grown in number
symptoms-- itchyness and throbbing red and swollen
by taking antibotics steoird or oral contraception it redues number of bacteria

 

[Tim035]

Yes you Must know about homozygous and heterozygous but its not like its a difficult concept.
Homozygous. Contains two of the sample allele in the genotype eg. (RR)
Heterozygous. Contains both alternatives for the characteristic in the genotype eg. (Rr).

I got a really quick questions:
- Name some substances which do not pass from the glomerulus into the bowmans capsule.

And on a paper I just did it said, what other function besides pressure filtration does the bowmans capsule perform? And I guessed, it keeps the interstitial fluid inside the kidney nephrons. Do you think thats right?

 

[simplistic]

teacher thought they would be perfect 8 mark questio so she made us prepared

 

[simplistic]

got a really quick questions:
- Name some substances which do not pass from the glomerulus into the bowmans capsule.

lager protiens rbc large molecules basically

And on a paper I just did it said, what other function besides pressure filtration does the bowmans capsule perform? And I guessed, it keeps the interstitial fluid inside the kidney nephrons. Do you think thats right?
duno ? post teh answer if you find it lol

 

[Tim035]

Mendel observed the inheritance of 7 characteristics in his experimentation with peas.

Peas have a chromosome number 2N= 14. It could be assumed each of these alleles was carried on a seperate chromosome to others, explain why.

If some alleles were linked on the one chromosome would it have made any difference to mendel's results? Explain

 

[Dr_Doom]

Yes linked characteristics produce the ratio 9:3:3:1 and unlinked are 3:1. If alleles were on the same chromosomes in Mendel's experiments he probably wouldn't have known how to interpret the results.

 

[Petinga]

Question: Describe the experiment conducted in your course of biolgy which showed the effects of temperature, pH and substrate concentration on a particular enzyme

Questionefine substrate concentration and enzyme

Question: Give an example of an oragnism and narrow temp range of survival.

Question: Describe the two stages of homeostasis

Questrion: Define nephron. Describe the role of nephrons in regulating bodys fluid composition

 

[Dr_Doom]

The higher the substrate concentration, the more active sites that will be occupied. initially it will increase in activity, but then will plateu as all active sites are occupied.

Human 37 degrees celcius

Detecting the change from the norm
Counteracting the change back to the norm

A structure in the kidney which filters blood. Absorb substances back into the blood by active or passive transport depending on the concentration of particular hormones. Secrete urea into collecting ducts.

Question: Describe TWO mechanisms in gene expression

Note: this thread will be dead tomorrow lol

 

[Petinga]

Gene expression in neccessary in assisting in the maintenace of health. Genes provide the code for protein production required for growth and repair. And since enzymes are proteins, then gene expression controls metabolism and hence cell activity.

thats all i knwo about gene expression

Questionescribe the importance of crick,watson, franklin and wilkins in DNA structure

 

[simplistic]

Gene expression in neccessary in assisting in the maintenace of health. Genes provide the code for protein production required for growth and repair. And since enzymes are proteins, then gene expression controls metabolism and hence cell activity.

thats all i knwo about gene expression

Questionescribe the importance of crick,watson, franklin and wilkins in DNA structure

by them discovering the structure of the dna
led to developmet of transgenic species
greater understanding of artifical insemination and pollenation

frankilin deveolped the xray diffracted images of dna
the stealer took them and gave them to watson and crik
they deveopled the corretc modle of dna
showed the base complemtary sequesnce
showed that nucliotied consists of sugar phosphate and nitrogenous base

 

[Dr_Doom]

Wilkins photographs of DNA using x-ray diffraction.
Franklin interpreted the photos and state the phosphate backbone goes on the outside. (hinting the helical structure)
This was enough for Crick and Watson to build a perfect model of DNA.

Question: Describe the broad range of temperatures in which life can exist.

 

[aileenli]

life can exist in a very broad range of temperatures from -40 deg C (muskoxen) to over 100 deg C (thermophilic bacteria that live near volcanic vents underwater)

 

[simplistic]

WAT FREAKS LOL
life -70 to 120
however indivduals exisit in a narrow range eg kangaroo 35-45