nexttttt (3 Viewers)

[2S1D3]

Some bacteria have natural genetic variation, through which they are resistant to the many antibiotics they are exposed to. As a result of natural selection, they pass on these favourable resistant characteristics to their offspring, thus producing a largely resistant strain. The overuse of antibiotics, as well as failure to complete antiobiotics courses, has led to resistant bacterial strains such as Staphylococcous Aurea - Golden Staph. This has become a major concern in Australian hospitals. This strain has developed resistance to ALL antibiotics, and thus poses grave health risks for any patient in the hospital that may be exposed to the dangerous pathogen.

Explain how advances in scientific understanding brought about by Mendel's discoveries provide evidence for the Darwin-Wallace theory of evolution by natural selection?

ahhh dunno if this is right
-Mendel suggested that genes can either be dominant ( expressed as a phenotype more often in the offspring) or recessive ( less often)
- He conducted these through pea plants and he discovered that the dominant genes in MOST cases were beneficial to the organism.
-This is relavant to Darwin's natural selection as it is concerned with a dominant gene's expression.
-The more chance this dominant gene has of 'surviving', the more likely it will be passed on to the offspring and eventually will be expressed as a favourable characteristic.
hehe dunno if i got a bit sidetracked there, btw danz90 do you have an answer to this?

 

[homijoe]

-Analyse and present information from secondary sources to report on the progress in the production of artificial blood and use available evidence to propose reasons why such research is needed.

-To overcome the shortage of donor blood
-Artifical blood does not need to be cross matched making it particualary useful in emergencies
-donor blood can be stored for a few weeks while Artifical blood can be stored indefinately making it again useful in emergencies
Artifical blood can be sterrilised to eliminate the risk of infection by pathogens

An example artifical blood that has been produced is; perflurochemicals, they are synthetic inert materials, cheap to produce and they can dissolve 50 times more oxygen then blood plasma.

 

[midifile]

Compare the structure of veins and arteries, and relate this to their role in the transport of blood around the body

 

[imqt]

GUYS QUICK GENERAL Q
Vaccines are use to treat viruses and bacterial infections? or is it just viruses

 

[midifile]

Traditionally only viruses. But they have developed vaccines to bacterial diseases such as tuberculosis, but I dont know if they work the same as normal vaccines.

In the exam i'd just say viruses. They wouldnt mark you down for it.

 

[2S1D3]

Compare the structure of veins and arteries, and relate this to their role in the transport of blood around the body

Veins:- thin walled blood vessels that have a large bore and have valves to prevent backflow.
-Essentially transport blood to the heart from the extremeties.
-Have a very low blood pressure, and usually transport deoxygenated blood, except for the pulmonary vein.

Arteries:- thick, muscular blood vessels, have a small diameter and have a large pressure because the blood is travelling from the heart.
- Transport blood from the heart to the extremeties.
-The blood present in arteries is in most cases oxygenated except for the pulmonary artery.

Outline the process by which DNA controls the production of polypeptides.

 

[imqt]

Traditionally only viruses. But they have developed vaccines to bacterial diseases such as tuberculosis, but I dont know if they work the same as normal vaccines.

In the exam i'd just say viruses. They wouldnt mark you down for it.

yeh i was wondering cause pasteur isolated the bacterium for anthrax disease and developed a vaccine for it...so that got me confused because i associated antibiotics with bacteria, and vaccines with viruses

 

[imqt]

Veins:- thin walled blood vessels that have a large bore and have valves to prevent backflow.
-Essentially transport blood to the heart from the extremeties.
-Have a very low blood pressure, and usually transport deoxygenated blood, except for the pulmonary vein.

Arteries:- thick, muscular blood vessels, have a small diameter and have a large pressure because the blood is travelling from the heart.
- Transport blood from the heart to the extremeties.
-The blood present in arteries is in most cases oxygenated except for the pulmonary artery.

Outline the process by which DNA controls the production of polypeptides.

DNA unwinds in nucleus by enzymes

mRNA transcribes the base sequence

mRNA moves out of nucleus to ribosomes

In ribosomes, tRNA translates mRNA's amino acid sequence

tRNA assembles amino acids to form the polypeptides

Polypeptide returns to nucleus

 

[midifile]

Outline the process by which DNA controls the production of polypeptides.

Transcription: At the site (locus) of an active gene, DNA unwinds, and the bonds between complementary base pairs are broken. The noncoding (template strand) acts as a template for the transcription of the sequence of bases in DNA to a sequence of bases in pre-mRNA, as free complementary nucleotides from the nucleoplasm join to the unpaired bases of the DNA. The sections of the pre-mRNA that correspond to introns in DNA are cut out. This strand of mRNA separates from the DNA, and leaves the nucleus through a pore on the nuclear membrane and moves to a ribosome.

Translation: The ribosome reads one codon (triplet of bases) at a time, and when a codon is in the reading frame a specific tRNA molecule delivers a specific amino acid depending on its anticodon. Peptide bonds form between amino acids (this is catalysed by the enzyme peptidase) to form a polypeptide.

EDIT: imqt beat me to it = P

 

[imqt]

Transcription: At the site (locus) of an active gene, DNA unwinds, and the bonds between complementary base pairs are broken. The noncoding (template strand) acts as a template for the transcription of the sequence of bases in DNA to a sequence of bases in pre-mRNA, as free complementary nucleotides from the nucleoplasm join to the unpaired bases of the DNA. The sections of the pre-mRNA that correspond to introns in DNA are cut out. This strand of mRNA separates from the DNA, and leaves the nucleus through a pore on the nuclear membrane and moves to a ribosome.

Translation: The ribosome reads one codon (triplet of bases) at a time, and when a codon is in the reading frame a specific tRNA molecule delivers a specific amino acid depending on its anticodon. Peptide bonds form between amino acids (this is catalysed by the enzyme peptidase) to form a polypeptide.

EDIT: imqt beat me to it = P

the more answers the better!! its good readings other peoples answers

 

[bekmay]

hey guuys love this little system you have going here...
i was wondering if anybody can tell me the process by which single-stranded chromosomes are converted to double-stranded chromosomes after meiosis and fertilisation but prior to the division of the zygote? is this just DNA replication? prolly stupid question i know but its confusing me LOL.
=]

 

[imqt]

evaluate the effectiveness of vaccination programs in preventing the spread and occurrence of once common diseases including small pox, diphtheria and polio

 

[2S1D3]

yea its good, hehe I actually found the production of polypeptides the hardest in the course,
EDIT:
Smallpox: is caused by the virus Variola Major and is transmitted by the inhalation of infective droplets.
-Its symptoms include skin rash, headaches and even internal haemorrages.
-In 1796 Edward Jenner performed the first vaccination program to prevent the spread of smallpox, using a weakened
strain of a cowpox virus to protect a child suffering with smallpox.
-The vaccination program for smallpox began in the 60s and the last known case of smallpox occured in Somalia in 1977.

Diptheria: - caused by the bacteria Corynebacterium diptheriae, again is transmitted by the inhalation of infective droplets.
- One out of ten people die if not treated and vaccination programs for people from childhood have prevented the person
acquiring diptheria.
- There has been a resurgence of the disease lately as the causative organism has not been eradicated.

 

[barry1]

-To overcome the shortage of donor blood
-Artifical blood does not need to be cross matched making it particualary useful in emergencies
-donor blood can be stored for a few weeks while Artifical blood can be stored indefinately making it again useful in emergencies
Artifical blood can be sterrilised to eliminate the risk of infection by pathogens

An example artifical blood that has been produced is; perflurochemicals, they are synthetic inert materials, cheap to produce and they can dissolve 50 times more oxygen then blood plasma.

It's 5 times more oxygen than blood plasma (correct me if i'm wrong)

 

[Kujah]

GUYS QUICK GENERAL Q
Vaccines are use to treat viruses and bacterial infections? or is it just viruses

You've got diphtheria and tetanus as examples of bacterial diseases that have been successfully controlled by vaccinations.

EDIT: Also whooping cough.

 

[imqt]

It's 5 times more oxygen than blood plasma (correct me if i'm wrong)

your right

 

[imqt]

identify defence barriers --- LYMPH SYSTEM

 

[2S1D3]

Outline the reasons for the suppression of the immune response in organ transplant patients.

 

[bekmay]

=[
pleeease guys have a go at my question #131... or any suggestions??

 

[midifile]

The cells of organs have antigens (markers) on them. When an individual is given an organ transplant, these markers are recognised as being 'non self' by macrophages and as a result the body will mount an immune response against the transplanted organ and rejection will occur.

The immune response must be suppressed so that this does not occur.