nexttttt (3 Viewers)

[Takuto]

Evaluate the effectiveness of quarantine in preventing the spread of plant and animal diseases into Aus. or across regions of Aus.

It has been highly effective in preventing the entry and spread of diseases from foreign locations and across regions of Australia; the AQIS (Australian Quarantine Inspection Service) is responsible for the prevention of potential infectious materials entering Australia and being transported across regions

Each plant is tested for disease, such as Karnal Bunt or Plum Pox. Heat treatment is sometimes used to kill the seed, to prevent the spread of the disease.The AQIS also requires that all agricultural machinery be cleaned

All animals are tested and quarantined for disease on arrival, including the screw-worm fly or the varroa mite, which may both kill newborn cattle and cost up to 500 million a year.

Quarantine involves restricting movement of certain plants, animals, fruits and vegetables across and from forieign locations which may contain the disease and thus spread it.

Overall, quarantine in Australia has been very effective, it has prevented many diseases and epidemics from spreading across or into Australia. In turn, it has saved plant, animal and human lives (eg. absence of mad cow disease by banning import of live cattle), and also saved alot of money

Explain the process of meiosis

lol they ask about meiosis alot..

 

[Kujah]

For this evaluation, do we need to have specific examples or just generalise?

I guess so. Its always good to use examples

And excellent answer above!

Explain the process of meiosis

Do you want a detailed or generalised answer?

 

[Lordie]

What is Enantiostasis?

(They always seem to put this one in, heh)

 

[Kujah]

What is Enantiostasis?

(They always seem to put this one in, heh)

The maintenance of metabolic and physiological functions in responses to variations/fluctuations in the environment (yeah yeah, syllabus answer ). An example of an environment where enantiostasis is critical is an estuary.
- You can point out to fluctuation in salinity and tidal levels.
- Perhaps give an example of an organism eg- oysters, crabs, halophytes.

Explain the role of gamate formation and sexual reproduction in variability of offspring.

 

[danz90]

The maintenance of metabolic and physiological functions in responses to variations/fluctuations in the environment (yeah yeah, syllabus answer ). An example of an environment where enantiostasis is critical is an estuary.
- You can point out to fluctuation in salinity and tidal levels.
- Perhaps give an example of an organism eg- oysters, crabs, halophytes.

Explain the role of gamate formation and sexual reproduction in variability of offspring.

Gamete formation through the process of meiosis, results in a haploid number of chromosomes (23). As a result of random segregation and independent assortment of genes, and crossing over of chromosomes, gametes observe unique genetic variability. Sexual reproduction involves the random fusion of a sperm and ovum, where two sets of haploid number of chromosomes fuse (one set from each parent). Hence, there is a variability in the offspring.

I don't like my answer, since I hate this area of the course.

Next: Outline the process of DNA replication.

 

[Kujah]

Gamete formation through the process of meiosis, results in a haploid number of chromosomes (23). As a result of random segregation and independent assortment of genes, and crossing over of chromosomes, gametes observe unique genetic variability. Sexual reproduction involves the random fusion of a sperm and ovum, where two sets of haploid number of chromosomes fuse (one set from each parent). Hence, there is a variability in the offspring.

I don't like my answer, since I hate this area of the course.

Next: Outline the process of DNA replication.

1. The DNA molecule unwinds into two separate strands (due to action of enzymes eg-helicase)
2. As the two strands become exposed, free nucleotides in the nucleoplasm attach themselves to the exposed bases (remember complementary bases A-t C-g).
3. The joining of the nucleotides together is done so by DNA polymerase. When completed, each new DNA molecule is twisted back into a double helix shape.

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

 

[danz90]

1. The DNA molecule unwinds into two separate strands (due to action of enzymes eg-helicase)
2. As the two strands become exposed, free nucleotides in the nucleoplasm attach themselves to the exposed bases (remember complementary bases A-t C-g).
3. The joining of the nucleotides together is done so by DNA polymerase. When completed, each new DNA molecule is twisted back into a double helix shape.

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

Louis Pasteur contributed the germ theory of disease - that microorganisms such as bacteria are the cause of disease. This was proved through his experiment using flasks containing beef broth. When exposed to air, decay was observed since the mixture was exposed to airborne microorganisms. This also proved that microorganisms are also airborne. He disproved the spontaneous generation theory.

Koch contributed to the understanding that specific microorganisms are the causative agents for particular diseases. He developed Koch's postulates, which are a set of principles that are used to identify specific microorganisms as the cause of a particular disease.

Explain how the processes of reabsorption and filtration in the mammalian nephron regulate body fluid composition.

 

[Kujah]

Louis Pasteur contributed the germ theory of disease - that microorganisms such as bacteria are the cause of disease. This was proved through his experiment using flasks containing beef broth. When exposed to air, decay was observed since the mixture was exposed to airborne microorganisms. This also proved that microorganisms are also airborne. He disproved the spontaneous generation theory.

Koch contributed to the understanding that specific microorganisms are the causative agents for particular diseases. He developed Koch's postulates, which are a set of principles that are used to identify specific microorganisms as the cause of a particular disease.

Explain how the processes of reabsorption and filtration in the mammalian nephron regulate body fluid composition.

- Talk about the filtration of blood into the Bowman's capsule. The composition of the glomerular filtrate and its contents eg- water, urea, ions, vitamins, salts, sugars. Blood cells and proteins are blocked from entering due to their sheer size, and now the body requires the process of reabsorption in order to extract necessary substances back into the blood.
- Reabsorption occurs along the tubules (proximal and distal) and along the loop of Henle.
- Glucose, vitamins, amino acids are recovered back into the blood. Salt ion reabsorption occurs (depending on the type of ion, active or passive transport can be used) depending on the concentration within the blood vessels, and water is moved back thru osmosis along all parts of the nephron except for the ascending part. You can discuss the role of secretion, and how waste substances such as urea or aspirins can be actively pushed into the nephron from the capillaries.
- Through these reabsorption processes and the concentration of the filtrate, the body fluid composition can be maintained at a homeostatic level.

Bleh. Don't like answering that =p

Compare responses of named Aus. ectothermic and endothermic organisms to changes in the ambient temperature and explain how these responses assist temp. regulation.

 

[flemodude]

im doing bio just coz it was the only option i could do on that line that i had a slight interest in...i hav all the topics down pat except for the option: gentics code broken...i need help!

but anyway...

Ectotherm- Blue- tongue lizard, snakes and crocodiles- bask in sun when cool & inactive or seek shade at hottest part of day & drought
Endotherm- Red kangaroo & bilby- large ears (radiate heat), panting (cooling effect- evaporates water from mouth), lick forearms (evaporation of salvia cools body), vasoconstriction-reduces heat loss

would that be efficient for say a 5 mark Q?

 

[danz90]

- Talk about the filtration of blood into the Bowman's capsule. The composition of the glomerular filtrate and its contents eg- water, urea, ions, vitamins, salts, sugars. Blood cells and proteins are blocked from entering due to their sheer size, and now the body requires the process of reabsorption in order to extract necessary substances back into the blood.
- Reabsorption occurs along the tubules (proximal and distal) and along the loop of Henle.
- Glucose, vitamins, amino acids are recovered back into the blood. Salt ion reabsorption occurs (depending on the type of ion, active or passive transport can be used) depending on the concentration within the blood vessels, and water is moved back thru osmosis along all parts of the nephron except for the ascending part. You can discuss the role of secretion, and how waste substances such as urea or aspirins can be actively pushed into the nephron from the capillaries.
- Through these reabsorption processes and the concentration of the filtrate, the body fluid composition can be maintained at a homeostatic level.

Bleh. Don't like answering that =p

Compare responses of named Aus. ectothermic and endothermic organisms to changes in the ambient temperature and explain how these responses assist temp. regulation.

Example: Increased body temperature

Endotherm: Red Kangaroo
RESPONSES
Structural: Sheds body fur/hair in order to increase rate of sweating for cooling.
Physiological: Vasodialation in order for excess heat to be released in the extremities, to allow for counter-current exchange and thus maintaining a stable internal temperature.
Behavioural: Tucks in tail to prevent excessive absorption of heat (by reducing surface area exposed to heat)

Ectotherm: Frilled Neck Lizard
RESPONSES
Structural: Opens frill to increase to increase surface area for evaporation (through sweating) to cool body surface.
Physiological: Reduces skin pigmentation (melanin) to reflect heat away from body (seasonal response).
Behavioural: Seeks shelter and burrows itself to avoid the heat from sunlight. Forages at dawn and dusk to minimise sun (and thus heat) exposure.

I would put this info in a table, to show a comparison.

Describe and explain the immune response in the human body in terms of interaction between T and B lymphocytes.

 

[Kujah]

- Talk about how macrophage engulfs the antigen at first, and presents a segment on it on its MHC complex.
- Helper T-cells inspect the antigen and release interleukins to stimulate the production of B and T-cells based on this specific type of antigen.
- T-cells differentiate into Cyotoxic Killer T cells, Memory T cells, Suppressor Cells and are aimed predominantly at infected somatic cells (cell-mediated response)
- B cells differentiate into Plasma B cells (produce antibodies to counter against antigens in the blood) and Memory B cells.

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

 

[danz90]

- Talk about how macrophage engulfs the antigen at first, and presents a segment on it on its MHC complex.
- Helper T-cells inspect the antigen and release interleukins to stimulate the production of B and T-cells based on this specific type of antigen.
- T-cells differentiate into Cyotoxic Killer T cells, Memory T cells, Suppressor Cells and are aimed predominantly at infected somatic cells (cell-mediated response)
- B cells differentiate into Plasma B cells (produce antibodies to counter against antigens in the blood) and Memory B cells.

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

-An enzyme (helicase) unzips the DNA double strand, at the location where the gene coding for the protein is located.
-RNA polymerase joins complementary RNA nucleotides together, forming a messenger RNA strand.
-mRNA then travels outside of the nucleus into the cytoplasm, where it then attaches to a ribosome.
-The ribosome moves along the mRNA strand.
-tRNA molecules in the cytoplasm transport amino acids in the cytoplasm to their corresponding location as coded by the mRNA.
-the code on the mRNA ensures that amino acids are in a correct sequence.
-amino acids are then linked to each other by peptide bonds
-as the ribosome moves along the mRNA strand.. further amino acids are brought by tRNA molecules, forming a long amino acid chain (polypeptide)
-this sequence stops when the STOP codon is reached.

-Polypeptides are then released into the cytoplasm where they will link with other polypeptides to form a protein.

Describe the main changes in the composition of blood as it moves around the body and identify the tissues in which these changes occur.

 

[obiman]

The blood circulates through two systems in the body: the pulmonary system and the systemic system:

In the pulmonary system, blood flows from the heart to the lungs and then back to the heart. Blood travels in the pulmonary artery from the right ventricle to the lungs where carbon dioxide is released into the alveoli of the lungs. This is then ultimately released out of the body. Oxygen is picked up from the alveoli and diffused into the red blood cells to then be taken back to the heart. So via the pulmonary system, carbon dioxide is decreased and oxygen levels increased.

In the systemic system, blood flows from the heart to the rest of the body, except the lungs, and then returns. The left ventricle pumps oxygenated blood to the rest of the body, and as this blood circulates in capillaries, oxygen is delivered to the cells and carbon dioxide is picked up. Other waste products, such as urea, are also picked up from the liver and transported in the blood to the kidneys. Blood flowing to the small intestines collects the products of digestion and transports them to the liver. Glucose is circulated in the blood stream to all cells in the body for respiration. Deoxygenated blood returns to the heart via the inferior and superior vena cava.


outline the roles of Sutton and Boveri in identifying the importance of chromosomes??????

 

[midifile]

Sutton and boveri determined that Mendel's "factors of inheritance" were located on chromosomes, by comparing what Mendel said with the process of meiosis in their chromosomal theory of inheritance (1902).

Mendel said for each trait there is a pair of factors, and they saw that in cells there were pairs of homologous chromosomes; Mendel said that when gametes formed these factors separated, and in meiosis, the members of the homologous pairs are pulled to opposite poles (separating them); Mendel said that these factors are brought back together in fertilisation, and in fertilisation, gametes fuse to form a zygote. This suggested that Mendel's factors of inheritance were directly related to chromosomes

Sutton added that as individuals have thousands of characteristics and only 23 pairs of chromosomes, there musy be thousand of these factors linked on chromosomes

During your study of maintaining a balance you performed an experiment to show the effect of temperature on enzyme activity. Describe the procedure you carried out.

 

[katie tully]

good luck 08ers


there was none of this sort of, note sharing kinda stuff on BOS when i did my hsc

good to see

:wave:

 

[midifile]

good luck 08ers


there was none of this sort of, note sharing kinda stuff on BOS when i did my hsc

good to see

:wave:

=]

thanks

 

[dolbinau]

Does anyone have the Excel Biology book?

Can someone explain to be 2c) of the short answers in "Blueprint of life" questions?

thanks

 

[homijoe]

During your study of maintaining a balance you performed an experiment to show the effect of temperature on enzyme activity. Describe the procedure you carried out.[/quote]

although there are many ways to perform this experiment ill mention my method:

1. A water bath of approximately 37degrees was set up.
2. 3 test tubes were obtained and 5ml of milk was poured into 2 separate test tubes and 1ml of renin was poured in the remaining test tube.
3. all three test tubes were then placed in the water bath for 5mintues.
4. after 5minutes the test tube with the renin contents was poured into one of the test tubes containing milk. the remaining test tube with only milk represented the control experiment.
5. The time taken for the milk to clot was then recorded.
6. the procedure was repeated at different water bath temperatures 0 ( using ice cubes), 20, 40, 60 and 80 degrees celsius.
7. the entire experiment was repeated 3 times and the average result was calculated to minimise the effect of chance and to ensure reliable results were obtained.

Independent Variable: temperature
dependent Variable: Rate of activity of the enzyme renin (time taken to clot)
Controlled Variable: Same size test tubes, same amount of renin and milk and the same length of time before pouring the renin into a test tube of milk were kept constant throughout the entire experiment...


Q: Outline how Cell differentiation and Cell specialisation assist in maintaing health.

 

[Kujah]

Sutton added that as individuals have thousands of characteristics and only 23 pairs of chromosomes, there musy be thousand of these factors linked on chromosomes

Was it Boveri or Sutton who did that?

Can someone explain to be 2c) of the short answers in "Blueprint of life" questions?

Whats the question(s)?

 

[aussiechick007]

Q: Outline how Cell differentiation and Cell specialisation assist in maintaing health.

cell differentiation:
- cells formed from mitosis are differentiated for different functions in a multicellular organism.
- undifferentiated cells form tumours, thus why differentiation assists in the maintenance of health.
- proto-oncogenes regulate this cell differentiation and growth, and health is also affected if these become defective oncogenes

cell specialisation:
- cells are specialised to have focussed roles in maintaining health.
eg. specialised B and T cells that produced anitbodies to attack a disease-causing micro-organism.

erm....
Q. Discuss the importance of hormone replacement therapy for people who cannot secret aldosterone.