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dolbinau

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Aldosterone controls the reabsorption of sodium in nephrons. When sodium is reabsorbed, water also is reabsorbed by osmosis. Hormone replacement therapy, such as FlorineF, is important to ensure the homeostatic balance of sodium and blood pressure is maintained. (is this correct? do I need to be specific with the tubules? I can't remember them anyway so I'd have to look them up lol)

Whats the question(s)?
It's about Crossing Over. With a diagram, I often have trouble identifying or drawing the resultant genotypes. Is this meant straight forward?
 

Kujah

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dolbinau said:
Aldosterone controls the reabsorption of sodium in nephrons. When sodium is reabsorbed, water also is reabsorbed by osmosis. Hormone replacement therapy, such as FlorineF, is important to ensure the homeostatic balance of sodium and blood pressure is maintained. (is this correct? do I need to be specific with the tubules? I can't remember them anyway so I'd have to look them up lol)
You can mention Addison's disease and its effects/symptoms as well I guess.
 

Takuto

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aussiechick007 said:
Q. Discuss the importance of hormone replacement therapy for people who cannot secret aldosterone.
The adrenal glands secrete aldosterone. Without aldosterone, the body would not be able to regulate the reabsorbtion of salt in the nephrons, leading to excessive levels of potassium, irregular blood pressure and severe dehydration

If the adrenal gland is damaged, for e.g due to Addison's disease, aldosterone can no longer be secreted and the patient may suffer from vomiting, diarrhea, headache or swelling (no homeostasis)

the use of artificial hormones such as Fludrocortisone can be inserted through hormone replacement therapy. This artificial horomone does the job of aldosterone allowing an organism to function normally again.

shit answer but meh =]

Describe the theory of movement in the Xylem
 

dolbinau

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Transpiration - as water is evaporated from the stomata the cohension of water molecules moving in the xylem and adhesion of the molecules to the (cellulose?) walls of the xylem causes the water to rise; a continuous transpiration stream.

I hate it how my answers get pwned :p.

Outline the historical development of Malaria

(No looking :p)
 

Rfelt110191

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I have a question for all those bio ppl out there who get pissed off when textbooks/sheets/etc. have contradicting info
kk gone through a bunch of different sources:
one text book says ADH acts on the collecting duct, an hsc question in 2002 has ADH acting on the distil tubule and collecting duct, also I was under the impression that aldosterone acts on the loop of henle and distil tubule (which makes sense coz its salt reabsorption) but other sheets say otherwise...
I am going to explode :eek: can ne1 confirm nething for me!!
 

Kujah

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You can also mention adhesion, cohesion and capillarity in regards to the movement of water in xylem.

one text book says ADH acts on the collecting duct, an hsc question in 2002 has ADH acting on the distil tubule and collecting duct, also I was under the impression that aldosterone acts on the loop of henle and distil tubule (which makes sense coz its salt reabsorption) but other sheets say otherwise...
I was taught it was through the collecting ducts. And yeah, both the loop of Henle and distal tubule again with aldosterone.
 
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Kujah

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dolbinau said:
Outline the historical development of Malaria

(No looking :p)
lol, do we have to use dates? :p

Meh,

Ancient Greeks made the link between swamps and malaria.
188X- Charles Laveran inspects micro-organisms (Plasmodium protozoans) within blood samples of infected blood patients of malaria.
Golgi - ?!?
Patrick Manson proposes that the mosquito was the cause of malaria.
Grassi proposes that it was the female Anopheles mosquito.
189X- Ronald Ross observes the life cycle of the Plasmodium, and deduces that malaria is caused by the infection of the Plasmodium protozoan carried by the female Anopheles mosquito, and ultimately wins the Nobel Prize for his discovery.
You can discuss the discoveries of quinine and chloroquine in the 20th century as ways to treat malaria, and also the use of DDT in spraying.

Q: Outline the way the environment can impact on the gene expression of individuals.
 
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bendha

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Rfelt110191 said:
I have a question for all those bio ppl out there who get pissed off when textbooks/sheets/etc. have contradicting info
kk gone through a bunch of different sources:
one text book says ADH acts on the collecting duct, an hsc question in 2002 has ADH acting on the distil tubule and collecting duct, also I was under the impression that aldosterone acts on the loop of henle and distil tubule (which makes sense coz its salt reabsorption) but other sheets say otherwise...
I am going to explode :eek: can ne1 confirm nething for me!!
the 02 paper diagram says the ADH acts only on the collecting tubule whereas aldosterone acts on the collecting and distal tubules.you've lookat the them the wrong way around lulz
 

dolbinau

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Also, does the reabsorption of salt involve active or passive transport?
 

dolbinau

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Kujah said:
lol, do we have to use dates? :p
I can't remember if it was a past HSC or trial question (probably trial) but they said 4 dates was required for full marks.

The other one I hate is the historical development of evolution!
 

dolbinau

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Q: Describe TWO types of changes in DNA sequences that can result in changes in polypeptides produced
 

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dolbinau said:
Also, does the reabsorption of salt involve active or passive transport?
Both. Depends on the area of the nephron and the salt concentrations.
 

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Compare the size, shape and function of red blood cells and white blood cells
 

Kujah

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Takuto said:
Compare the size, shape and function of red blood cells and white blood cells
RBC:
- bioconcave, no nucleus, 7~ micrometres, carries oxygen through Hb to body cells, large numbers

WBC:
- irregular shape, nucleus, 10-15 micrometres (depending on type of WBC), part of the immune response and defence mechanisms of the body (inc. phagocytosis, antibody production), less numbers.

:S I'd use a table as well.

EDIT: Q: Outline the way the environment can impact on the gene expression of individuals.
 
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Bobbles22

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Kujah said:
RBC:
- bioconcave, no nucleus, 7~ micrometres, carries oxygen through Hb to body cells, large numbers

WBC:
- irregular shape, nucleus, 10-15 micrometres (depending on type of WBC), part of the immune response and defence mechanisms of the body (inc. phagocytosis, antibody production), less numbers.

:S I'd use a table as well.

EDIT: Q: Outline the way the environment can impact on the gene expression of individuals.
The phenotype (appearance) of an organism depends on the genotype, as well as the environment as it can alter the expression of this. Many factors can affect the expression of a gene including amount of food, amount of sunlight, exposure to the environment, disease, presence of other organisms, temperature, altitude etc. An example of where the environment has altered the expression of a gene is in emerging plant shoots. Plants have the gene for gene leaves but if they are put in a dark area with light sunlight then they will grow brown leaves but once they are put in an area with sunlight their leaves turn green. Another example is pea plants, a pea plant may have the genetics for tall height but if it doesn’t receive many nutrients than its growth will be stunted
 

dolbinau

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Another example change in pH affects phenotype (specifically colours) of Hydrangea.
 

dolbinau

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For Physical Environment, Chemical Environment and Competition of resources in affecting evolution; do we need to know specific examples of animals or can we generalise?
 

Bobbles22

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dolbinau said:
Q: Describe TWO types of changes in DNA sequences that can result in changes in polypeptides produced
Quickover view
Chromosomal and gene mutation.
A change in the DNA sequences is known as a mutation
Chromosomal mutations involve a change in a section of chromosome, it can be removed and transfered to another chromosomes, removed and reversed etc
Gene mutations involve the changing of only 1 base, causes frameshift. etc

Describe current theories about processes responsible for the movement of materials through plants in xylem and phloem tissue.
 

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