Biology 2013ers MARATHONN (4 Viewers)

[girlworld_club]

kidney-> Blood loses urea, and other toxic stuff
brain-> Blood loses oxygen
lungs-> Blood loses CO2 and gains O2
intestines-> Blood gains glucose and loses O2?
Where does glucose get lost....In the brain?

glucose is not lost in the brain. It is produced in the small intestine (where larger carbohydrates are broken down), and is removed in the liver (where metabolic products are converted into nitrogenous waste)

 

[ocatal]

Identify the changes that would occur in the body if the hypothalamus detects a drop in blood solute concentration.

 

[superSAIyan2]

Stimulates adrenal glands to ibncrease secretions of aldosterone.

Changes: increased permeability of distal tubules to salts (Na+, K+) -> increased reabsorption of salts ---> blood solute conc increases to optimal level (not too sure about this)

OR if blood solute conc is LOW it means high water concentration of blood, so ADH secretions are inhibited --> decreased permeability of collecting duct to water ---> decreased reabsorption of water ---> blood water conc decreases and hence solute conc increasesÍ

 

[ocatal]

Stimulates adrenal glands to ibncrease secretions of aldosterone.

Changes: increased permeability of distal tubules to salts (Na+, K+) -> increased reabsorption of salts ---> blood solute conc increases to optimal level (not too sure about this)

OR if blood solute conc is high it means high water concentration of blood, so ADH secretions are inhibited --> decreased permeability of collecting duct to water ---> decreased reabsorption of water ---> blood water conc decreases and hence solute conc increasesÍ

Yep second part is correct. Well done! First part would be incorrect as we can't assume that salts are the only contribution to solute concentrations.

 

[superSAIyan2]

thanks. i keep forgetting about organic solutes.

just realised i forgot to ask a question.

QUESTION : Evaluate the importance of Boveri and Sutton's experiments in our current understanding of inheritance and genetics

 

[fionarykim]

like all my ask.fm answers

I will if you like mine

 

[fionarykim]

thanks. i keep forgetting about organic solutes.

just realised i forgot to ask a question.

QUESTION : Evaluate the importance of Boveri and Sutton's experiments in our current understanding of inheritance and genetics

I always get these people confused...
Boveri- worked with sea urchins, and discovereed that 50% of the chromosomes come from the mothr and 50 came from the father, therefore he made a connection between chromosomes and hereditary. He also discovered that a full set of chromosomes was required for normal growth
Sutton- worked with grasshoppers, discovered that chromosomes halved during meiosis, and the number of chromosomes recombined afterr fertilisation. Also suggestd mendels factors were located in chromosomes
Both independently came up with the chromosomal theory of inheritence. This understanding allowed us to understand mendel's experiment and results better. Allowed us to understand that chromosomes played a role in inherritance, and hence more research with chromosomes were conducted when scientists dealed with inheritance.

Question- outline significant historical events which lead to our current understanding of malaria

 

[ocatal]

I always get these people confused...
Boveri- worked with sea urchins, and discovereed that 50% of the chromosomes come from the mothr and 50 came from the father, therefore he made a connection between chromosomes and hereditary. He also discovered that a full set of chromosomes was required for normal growth
Sutton- worked with grasshoppers, discovered that chromosomes halved during meiosis, and the number of chromosomes recombined afterr fertilisation. Also suggestd mendels factors were located in chromosomes
Both independently came up with the chromosomal theory of inheritence. This understanding allowed us to understand mendel's experiment and results better. Allowed us to understand that chromosomes played a role in inherritance, and hence more research with chromosomes were conducted when scientists dealed with inheritance.

Question- outline significant historical events which lead to our current understanding of malaria

1880 - Charles Laveran discovered that Plasmodium was the pathogen which was the cause of malaria.
1885 - Camillo Golgi proved that there were 2 forms of the disease.
1897 - Ronald Ross revealed that malaria could be transmitted through mosquitoes.
1950 - WHO launches an unsuccessful attempt at eradicating malaria by killing mosquito populations using DDT. It is further uncovered that the mosquitoes could build resistance to the pesticide.

I think those are the most important.

Identify and describe 3 defence adaptations.

 

[superSAIyan2]

Early time: hypothesis that malaria was caused by drinking bad water, being bitten by swamp insects or inhaling bad/swampy air
1880: Laveran discovers Plasmodium protozoa responsible for malaria through microscopic examination of blood from infected patients
1897: Ronald Ross determined the cycle of transmission of malaria after discovering malarial cysts in Anopholes mosquiotoe's stomach (it is a vector for malaria)
1898 : Undertanding that malaria in humans is transmitted by humans

Would you need to mention the development of drugs in the timeline? Not sure if thats 'understanding of malaria'

Question: Describe the role of mitosis and cell differentiation in the maintenance of health in organisms.

 

[fionarykim]

1880 - Charles Laveran discovered that Plasmodium was the pathogen which was the cause of malaria.
1885 - Camillo Golgi proved that there were 2 forms of the disease.
1897 - Ronald Ross revealed that malaria could be transmitted through mosquitoes.
1950 - WHO launches an unsuccessful attempt at eradicating malaria by killing mosquito populations using DDT. It is further uncovered that the mosquitoes could build resistance to the pesticide.

I think those are the most important.

Identify and describe 3 defence adaptations.

Defence adaptations are also known as the second line of defence
-cell death, sometims the cells surrounding a pathogen will die off and trap the pathogen, this prevents it from leaving the area and infecting healthy cells. Then toxins are released to kill the pathogen.
Inflammation response: there would be a greaterr amount of blood flow to the infected area, this increases the amount of white blood cells in the area to defend against the disease. This is why we swell and have red warm burning skin when we hurt cut ourselves.
Phagocytosis- phagocytes such as macrophages engulf foreign materials and self destruct? Or do they release toxins to kill them? Damm i forgot

 

[obliviousninja]

Reading all these posts, is making me seem that I'm screwed for bio.

 

[ocatal]

Defence adaptations are also known as the second line of defence
-cell death, sometims the cells surrounding a pathogen will die off and trap the pathogen, this prevents it from leaving the area and infecting healthy cells. Then toxins are released to kill the pathogen.
Inflammation response: there would be a greaterr amount of blood flow to the infected area, this increases the amount of white blood cells in the area to defend against the disease. This is why we swell and have red warm burning skin when we hurt cut ourselves.
Phagocytosis- phagocytes such as macrophages engulf foreign materials and self destruct? Or do they release toxins to kill them? Damm i forgot

I think with cell death, the whole granuloma is engulfed by phagocytes. And for phagocytosis, the phagocytes engulf the foreign particle and release enzymes. Cytotoxic T-cells release the toxins during the immune response.

 

[ocatal]

Early time: hypothesis that malaria was caused by drinking bad water, being bitten by swamp insects or inhaling bad/swampy air
1880: Laveran discovers Plasmodium protozoa responsible for malaria through microscopic examination of blood from infected patients
1897: Ronald Ross determined the cycle of transmission of malaria after discovering malarial cysts in Anopholes mosquiotoe's stomach (it is a vector for malaria)
1898 : Undertanding that malaria in humans is transmitted by humans

Would you need to mention the development of drugs in the timeline? Not sure if thats 'understanding of malaria'

Question: Describe the role of mitosis and cell differentiation in the maintenance of health in organisms.

The timeline mainly indicates attempts at producing vaccines and seeing as they were all unsuccessful, I don't think it has enhanced 'understanding of malaria.' Maybe just learn one example though to mention if there happens to be a 7-marker on understanding of malaria.

 

[ocatal]

Early time: hypothesis that malaria was caused by drinking bad water, being bitten by swamp insects or inhaling bad/swampy air
1880: Laveran discovers Plasmodium protozoa responsible for malaria through microscopic examination of blood from infected patients
1897: Ronald Ross determined the cycle of transmission of malaria after discovering malarial cysts in Anopholes mosquiotoe's stomach (it is a vector for malaria)
1898 : Undertanding that malaria in humans is transmitted by humans

Would you need to mention the development of drugs in the timeline? Not sure if thats 'understanding of malaria'

Question: Describe the role of mitosis and cell differentiation in the maintenance of health in organisms.

Mitosis is the division of cells, producing identical body cells. This allows for growth and repair of any damaged tissue, integral to the maintenance of health in organisms as it means cells will function normally. On the other hand, cell differentiation involves the maturation of cells meaning they take on various structural features and perform specific functions. This is important for the maintenance of health as complex functions can be undertaken by the body.

Outline the implications of an imbalance of microflora in humans.

 

[superSAIyan2]

An imbalance of microflora can be caused by bodily stress, infections and the use of drugs which may reduce the populations of certain micro-organisms. This reduces the competition for resources for other micro-organisms allowing them to reproduce uncontrollably (i.e. above the natural levels) which results in infection in humans ; e.g. Thrush is caused when the populations of C.albicans in the digestive, urinary or respiratory tract exceeds natural levels due to reduced populations of Lactobacilli and other resource-competing bacteria.

Question : Describe an international vaccination program that has been undertaken to reduce the incidence of a named infectious disease and evaluate its effectiveness.

 

[ocatal]

An imbalance of microflora can be caused by bodily stress, infections and the use of drugs which may reduce the populations of certain micro-organisms. This reduces the competition for resources for other micro-organisms allowing them to reproduce uncontrollably (i.e. above the natural levels) which results in infection in humans ; e.g. Thrush is caused when the populations of C.albicans in the digestive, urinary or respiratory tract exceeds natural levels due to reduced populations of Lactobacilli and other resource-competing bacteria.

Question : Describe an international vaccination program that has been undertaken to reduce the incidence of a named infectious disease and evaluate its effectiveness.

Smallpox is a deadly virus which causes high fever and fatal rashes. Smallpox was responsible for the death of many people, greater than any other infectious disease. The World Health Organisation planned a mass immunisation program which was believed would eliminate smallpox. Proving to be successful, in 1979 it was declared that smallpox had been eradicated. Consequently, the vaccination program for smallpox has been very effective in reducing the incidence of the disease.

Identify and describe an example of hybridisation within a species.

 

[obliviousninja]

Smallpox is a deadly virus which causes high fever and fatal rashes. Smallpox was responsible for the death of many people, greater than any other infectious disease. The World Health Organisation planned a mass immunisation program which was believed would eliminate smallpox. Proving to be successful, in 1979 it was declared that smallpox had been eradicated. Consequently, the vaccination program for smallpox has been very effective in reducing the incidence of the disease.

Identify and describe an example of hybridisation within a species.

Tritical: Combination of rye (disease tolerance) and wheat (higher yield).
Not sure if that answer is good enough, obviously, I could put it in better terms, but yea.

Explain the relationship between the structure and behaviour of chromosomes during meiosis and the inheritance of genes.

 

[ocatal]

Tritical: Combination of rye (disease tolerance) and wheat (higher yield).
Not sure if that answer is good enough, obviously, I could put it in better terms, but yea.

Explain the relationship between the structure and behaviour of chromosomes during meiosis and the inheritance of genes.

Its fine haha. In an exam though make sure you also define hybridisation and mention it's purpose (to reach hybrid vigour).

 

[superSAIyan2]

Explain the relationship between the structure and behaviour of chromosomes during meiosis and the inheritance of genes.

Meiosis is a reduction cell division aimed to produce a wide genetic variety of gametes with the haploid condition.
- During cross-over double stranded homologous chromosomes pair up and exchange genetic material to produce recombinant chromosomes whose allelic forms differ from the parent chromosomes and to allow linked genes to be inherited independently.
- The random segragation of double stranded chromosomes into daugther cells and single stranded chromosomes into gametes is an independent process.
- Both these processes increases the possible combinations of alleles in the gametes which can be inherited by the offspring.

Question : A student makes the claim that "All mutations are harmful as they cause conditions such as Haemophilia and Down Syndrome." Discuss this statement with reference to your understanding of natural selection.

 

[fionarykim]

Question : A student makes the claim that "All mutations are harmful as they cause conditions such as Haemophilia and Down Syndrome." Discuss this statement with reference to your understanding of natural selection.

This statement is inaccurate as not all mutations are harmful
-mutations are a sudden change in the DNA which can be caused by deletion or insertion etc to the bases of the DNA
-under many circumstances, mutations are harmful as they cause they lead to abnormal development
-However if the mutation allows an organism to function better within a certain environment, or allows them to gain an advantage when there is an environmental change then this can become a benefit for the organsim. Darwin's theory of natural selection illustrates that within any population, there would be variations. The environment would place selective pressures on these organisms, and if a specific group or individual is better suited to the change, then they would have a higher chance of surviving and passing on their characteristics. Hence overtime the population may evolve. Since mutations cause variations, and may also lead to new alleles, if these variations caused by mutations end up giving the individual selective advantage, then this mutation would provide as a benefit. These characteristics may then be passed on and over time allow the population to evolve. therefore not all mutations are harmful

explain the interaction of B and T cells and explain the mechanism which allows for their interaction