nexttttt (2 Viewers)

[midifile]

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

I dont really get what you are asking

 

[imqt]

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

The immune system is suppressed because antibodies will be stimulated in response to the foreign antigen, being the organ transplant. This will attack the organ, and attempt to destroy it. Thus the immune system is suppressed in order for a successful organ transplant operation to be carried out

 

[2S1D3]

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

I can't answer that, I thought it's the segregation of chromosomes but I'm probably wrong, just look it up on wikipedia or something.

 

[imqt]

CAN SOMEONE PLEASE EXPLAIN the LYMPH system as a second barrier of defence?

i dont really get it, much appreciated

 

[syriangabsta]

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

The immune response is initiated if any foreiggn protiens are detected. This immune response will release B-Cells and Helper-T Cells whicih initiate the production of killer-t cells and kill any foreign stuff (LOL @stuff, cant think of word right now). If in an organ transplant, the immune system is not suppressed, the organ wil be killed..and the patient could die due to missing a vital organ for a certian amount of time.

thus it is vital to suppress immune system so that the organ can be placed w/ no problems. After the organ is placed, the "self" protiens are created on the surface of the organ, which don't initiate the immune response once the suppression is over.


yer uhh, hmm,

describe, using specific examples, how
the theory of evolution is supported by
the following areas of study:
− palaeontology, including fossils that
have been considered as transitional
forms
− biogeography
− comparative embryology
− comparative anatomy
− biochemistry

(xD exact dot point)

 

[bekmay]

I dont really get what you are asking

I can't answer that, I thought it's the segregation of chromosomes but I'm probably wrong, just look it up on wikipedia or something.

hahah mmk... well dw then, thanks anywhooo =] wiki here i come.

 

[midifile]

CAN SOMEONE PLEASE EXPLAIN the LYMPH system as a second barrier of defence?

i dont really get it, much appreciated

I suck at lymph system too =[ surely someone on here can do it

 

[2S1D3]

CAN SOMEONE PLEASE EXPLAIN the LYMPH system as a second barrier of defence?

i dont really get it, much appreciated

-Lymph system filters lymph fluid as it passes through lypmh nodes, it is this area where foreign proteins (i.e. antigens) and tumour cells are engulfed in the process of phagocytosis by macrophages.
-At these nodes, B Cells make antibodies agains antigens recognised by the body.

EDIT: Outline how the function of genes, and mitosis assist in the maintenance of health.

 

[Kujah]

CAN SOMEONE PLEASE EXPLAIN the LYMPH system as a second barrier of defence?

i dont really get it, much appreciated

- Phagocytes can travel through the lymph system to destroy antigens/pathogens.
- You've got lymph nodes around our body - they engulf and destroy bacteria and other foreign materials; thats why they become swollen in times of infection.
- Lymphocytes become active during inflammation and subsequently you got the B and T cells.

 

[bekmay]

ooh i wanna play.

EDIT: Outline how the function of genes, and mitosis assist in the maintenance of health.

As cells form from a zygote after reproduction, there is a particular stage that is reached where the cells begin to differentiate into muscle cells, nerve cells, epithelial cells, etc. During differentiation, only the genes necessary for the functioning of the specialised cell remain 'switched on'. The other genes remain 'switched off'. This ensures that all vital functions are carried out in allocating specific functions to specific cells eg. muscle cells require contractile proteins (actin or myosine) and the genes that synthesise these proteins remained switched on in muscle cells. Mitosis is controlled by genes in the cell for growth and repair. When cells are damaged (eg. through injury), mitosis produces new healthy cells close to the injury site, thus maintaining health in the organism.

Q. Identify a transgenic species, state its use and state one process used to produce transgenic species.
hope that hasn't been asked yet... LOL.

 

[imqt]

ok, thanks

 

[2S1D3]

ooh i wanna play.



As cells form from a zygote after reproduction, there is a particular stage that is reached where the cells begin to differentiate into muscle cells, nerve cells, epithelial cells, etc. During differentiation, only the genes necessary for the functioning of the specialised cell remain 'switched on'. The other genes remain 'switched off'. This ensures that all vital functions are carried out in allocating specific functions to specific cells eg. muscle cells require contractile proteins (actin or myosine) and the genes that synthesise these proteins remained switched on in muscle cells. Mitosis is controlled by genes in the cell for growth and repair. When cells are damaged (eg. through injury), mitosis produces new healthy cells close to the injury site, thus maintaining health in the organism.

Q. Identify a transgenic species, state its use and state one process used to produce transgenic species.
hope that hasn't been asked yet... LOL.

Salmon: - have been inserted with the BGH hormone that produces faster and larger fish.
- This provides food to many countries with salmon as their staple diet, thus providing food to a large number of people without adversely affecting salmon population.

Method:- a fertilised egg is removed from an organism and a particular gene is inserted, e.g. larger stature.
-A molecular vehicle is combined with the required gene and this combination is known as a transgene.
-The transgene is placed into the fertilised egg and this is allowed to develop in a mother, if this process has been executed correctly, a transgenic organism is resulted.

Describe the contribution of Pasteur and Koch to our understanding of infectious diseases.

 

[imqt]

The immune response is initiated if any foreiggn protiens are detected. This immune response will release B-Cells and Helper-T Cells whicih initiate the production of killer-t cells and kill any foreign stuff (LOL @stuff, cant think of word right now). If in an organ transplant, the immune system is not suppressed, the organ wil be killed..and the patient could die due to missing a vital organ for a certian amount of time.

thus it is vital to suppress immune system so that the organ can be placed w/ no problems. After the organ is placed, the "self" protiens are created on the surface of the organ, which don't initiate the immune response once the suppression is over.


yer uhh, hmm,

describe, using specific examples, how
the theory of evolution is supported by
the following areas of study:
− palaeontology, including fossils that
have been considered as transitional
forms




− biogeography



− comparative embryology




− comparative anatomy


− biochemistry


(xD exact dot point)

− palaeontology, including fossils that
have been considered as transitional
forms

palaeontology is the study of fossils, which are living remains of organisms from the past. They provide links to the past, and evidence for evolutionary relationships. Transnational fossils are those which show a link between the five vertebrate groups. Archaopteryx proposes that birds evolved from reptiles. It was an animal which had feathers, wish bone sternum, (bird characteristics) and teeth/claws (reptile) LopeFin Fish is also one, which shows that amphibians may have evolved from fish. It has scales and gills, aswell as lungs and limps. This supports that theory of evolution are organisms evolved from a common ancestor


− biogeography


this is the study of the distribution of species. A classic example is Darwin's finches, who are located on the Galopago's islands. They evolved from a common ancestor yet diverged into new environments and developed new characteristics as a result of natural selections eg. beaks --- different food sources.

− comparative embryology


this is studying the embryo's of vertebrates. All vertebrated had gill arches and a tail. This indicated that life began in the aquatic regions, and soon evolved different characterisitics as a result of different environments 9except fish)

− comparative anatomy

This is comparing the structure of organisms. The vertebrate groups all inhibit a pentedactyl limb. This may indicated a common ancestor. Yet it is different for each organism, due to natural selection. EG. Whale has short, thick dense bones for water resistence and propelling through water. Bat has thin, hollow enlongated fingers which are light for flight and helps them through air resistance


− biochemistry

this is the study of the genetic makeup fo each organism and comparing different organisms DNA/RNA. It has been useful in examing primate evolution. Humans have been found to be closely related to chimpanzees, with 97% protein precipation. Methods include DNA Hybridisation, DNA-DNA sequencing, Karyotype analysis etc

 

[bekmay]

Salmon: - have been inserted with the BGH hormone that produces faster and larger fish.
- This provides food to many countries with salmon as their staple diet, thus providing food to a large number of people without adversely affecting salmon population.

Method:- a fertilised egg is removed from an organism and a particular gene is inserted, e.g. larger stature.
-A molecular vehicle is combined with the required gene and this combination is known as a transgene.
-The transgene is placed into the fertilised egg and this is allowed to develop in a mother, if this process has been executed correctly, a transgenic organism is resulted.

Describe the contribution of Pasteur and Koch to our understanding of infectious diseases.

Louis Pasteur studied fermentation in wine and beer and stated that the products of alcohol and lactic acid are made by microbes, thus disproving the theory of spontaneous generation. Called the germ theory , this marked the beginning of the science of microbiology. Robert Kock proved this theory by extracting the anthrax bacillus and culturing it, and then used this culture to infect other animals which then developed the disease. Koch's postulates, which are a set of conditions that must be achieved in order to prove that a microbe causes a disease, were then developed. Our modern day understanding of infectious diseases were developed from Pasteur and Koch's contibution to the science of microbiology.

Q. Summarise the events that lead to Beadle and Tatum's 'one gene- one-protein' theory.

 

[homijoe]

Louis Pasteur studied fermentation in wine and beer and stated that the products of alcohol and lactic acid are made by microbes, thus disproving the theory of spontaneous generation. Called the germ theory , this marked the beginning of the science of microbiology. Robert Kock proved this theory by extracting the anthrax bacillus and culturing it, and then used this culture to infect other animals which then developed the disease. Koch's postulates, which are a set of conditions that must be achieved in order to prove that a microbe causes a disease, were then developed. Our modern day understanding of infectious diseases were developed from Pasteur and Koch's contibution to the science of microbiology.

Q. Summarise the events that lead to Beadle and Tatum's 'one gene- one-protein' theory.

Beadle and Tatum carried our research on the bread mould Neurosporo Crassa. They grew the mould on a minimal medium of sugar salts and the vitamin biotin. They reasoned that these substances were converted by the mould into amino acids and that enzymeswwere reresponsible for this. They subjected the mould to x-rays to cause mutations. They then tried to grow it on a minimal medium if it failed to grow they tried to grow it on a variety of media each containing a different amino acid. They found that the mutant strain had lost the ability to produce one amino acid this was because they lacked a particular enzyme. They then concluded that one gene codes for one enzyme and since enzymes are made of proteins it became know as the One gene-One protein hypothesis.

Distinguish between fungi and macro parasites. in terms of their distinguishable features and name 2 example of a disease caused by each type of pathogen

 

[o7nesss]

does anyone do the genetics option???

i need helpp!!!

whats the difference between homologue, homeotic and hox genes???

 

[Kujah]

Fungi- multicellular, eucaryotic, heterotrophic, cell wall made of chitin. eg- candiasis, tinea
Macroparasites - Organisms such as insects that cause disease and are visible to the eye. Can be ectoparasites or endoparasites eg- hydatid disease, taeniasis

Describe the chemical nature of chromosomes and genes

 

[Bobbles22]

does anyone do the genetics option???

i need helpp!!!

whats the difference between homologue, homeotic and hox genes???

Groups of genes that code for similar structure and function in different species are said to be homologous and are called gene homologuesHomeotic genes are genes that all contain a similar region of 180 base pairs called the homeoboxIn both mammals and insects the physical order of homeotic genes along a chromosome corresponds to order of action ie head to toe. The base sequence of the homeobox in insects (HOM) is 80% similar to the corresponding region in the homeobox in mammals (HOX).

 

[Bobbles22]

Fungi- multicellular, eucaryotic, heterotrophic, cell wall made of chitin. eg- candiasis, tinea
Macroparasites - Organisms such as insects that cause disease and are visible to the eye. Can be ectoparasites or endoparasites eg- hydatid disease, taeniasis

Describe the chemical nature of chromosomes and genes

Chromosomes are made up of 40% DNA and 60% protein.
Genes are segments of DNA and are therefore composed of varying length of nucleotides, which are composed a sugar, a phosphate and a base, therefore genes are composed at sugar, phosphate and base molecules.

 

[imqt]

Fungi- multicellular, eucaryotic, heterotrophic, cell wall made of chitin. eg- candiasis, tinea
Macroparasites - Organisms such as insects that cause disease and are visible to the eye. Can be ectoparasites or endoparasites eg- hydatid disease, taeniasis

Describe the chemical nature of chromosomes and genes

Chromosomes are made of 60% protein and 40% DNA with a protein coiled around it. DNA is nucleic acid with a double helx structure, phosphate-sugar backbone, and complementory bases. Genes are a section of DNA on a chromosome and code for particular characterisitc