- Messages
- 33
- Reaction score
- 23
- Points
- 8
Hahah i guess they occasionally do 
whats your idea of a correct answer then?
whats your idea of a correct answer then?-
We need your support!
We are currently struggling to cover the operational costs of Xtremepapers, as a result we might have to shut this website down. Please donate if we have helped you and help make a difference in other students' lives!
Click here to Donate Now (View Announcement)
Bio p41 how was it
- Thread starter Thampi4
- Start date
- Messages
- 50
- Reaction score
- 36
- Points
- 28
haha, exactly, i was thinking about the same thing but then i thought that would be morally wrong.so dey travel all around da world and pass dr allele??
i don't remember, Natural selection would occur, and stabilising speciation, stuff like that i guess.
- Messages
- 33
- Reaction score
- 23
- Points
- 8
I did give bits and pieces of natural selection. but what sort of selection pressure did u write?
- Messages
- 321
- Reaction score
- 232
- Points
- 53
A mod's going to come in here any minute now and then:
We all gonna die.
We all gonna die.
- Messages
- 321
- Reaction score
- 232
- Points
- 53
LMAO. The examiners are going to have a very very fun time reading our answers to their questions.
- Messages
- 64
- Reaction score
- 15
- Points
- 18
haha..what did you guys write for the polar bodies question? the IVF one.
- Messages
- 3
- Reaction score
- 2
- Points
- 13
Guys I found the paper very hard, nothing from the previous papers! Not much was repeated. Did anyone else find it hard. I will definately get 65+. Do you think that is an A? :/ How much will the grade threshold be?
- Messages
- 27
- Reaction score
- 6
- Points
- 13
i was shocked by the number of questions that i was asked to suggest !!after alll that studying u answer questions on mosquitos!!!!! but anyways i was confused on how large quantities of gm mosquitees can be produced from a gm mosquito stock?
- Messages
- 301
- Reaction score
- 114
- Points
- 53
I guess it's safe ti discuss now. So...
I wrote that, it's when there is a first polar body, the oocyte has gone through meiosis, so the cell is a haploid cell.
- Messages
- 4
- Reaction score
- 0
- Points
- 1
grade boundaries anyone? im hoping its something like 60-63 for A
- Messages
- 20
- Reaction score
- 8
- Points
- 3
It's going to be something like 70-73 because some ppl scored even above 80...
- Messages
- 216
- Reaction score
- 51
- Points
- 38
That's also what I said
- Messages
- 216
- Reaction score
- 51
- Points
- 38
- Messages
- 80
- Reaction score
- 24
- Points
- 18
What about that question where so many gm mosquitoes were produced from a small bunch??
- Messages
- 321
- Reaction score
- 232
- Points
- 53
I wrote put them in an enclosed area and provide breeding grounds... fresh water pond with standing water.
EDIT: Of course include the female non-GM mosquitoes too.
- Messages
- 301
- Reaction score
- 114
- Points
- 53
Conc. of CO2 in, and conc.of CO2out. If the conc. goes down, the lizard is respiring anaerobically
- Messages
- 80
- Reaction score
- 24
- Points
- 18
I wrote something about providing them with proper food and conditions or something....and i think i messed up that test cross between the cats too,i wasnt thinking rightI wrote put them in an enclosed area and provide breeding grounds... fresh water pond with standing water.
EDIT: Of course include the female non-GM mosquitoes too.
does anyone remember the answers to that one?
- Messages
- 301
- Reaction score
- 114
- Points
- 53
What did you guys do for the measurements?
Hello everyone, our exam was two days ago, so I'll try to remember my answers and post them here.
1) A: palisade mesophyll cells; B: guard cell; C: air space
How does carbon dioxide enter: it enters through the stomata by diffusion where it will travel through the air spaces until it is absorbed by the (photosynthesizing) cells
Role of reduced NADP: it is used to reduce 3-PGA (along with two ATP) to G3P (PGAL).
2) (I think this was the GM mosquito one)
Why didn't the fever incidence increase immediately: disease could only be carried on female mosquitoes (similiar to Anopheles) and since only male mosquitoes were sent, the incidence did not rise immediately. I also wrote that since they were GM mosquitoes, they could have the "infection" gene removed while they were transformed anyways.
How was it positive feedback: tTA acts as an operator, so as the production/concentration of tTA increases, so does the expression of the gene that translates to it.
How does chemical A prevent death: it could act as an enzyme inhibitor preventing tTA from being metabolized into a harmful toxin. Or, it could react with tTA directly to neutralize it into a harmless product.
How to make 3 million GM mosquitoes: mate a GM mosquito with a non-GM female mosquito (from the wild) and place the eggs in a solution containing chemical A. Or, inject chemical A in all the embryos.
3) What is meant by continuous culture: (I think this is pretty much self-explanatory)
Explain why fungi must be replaced before reaching the mutant stage: I wrote 4 reasons for this one, as there were 4 marks:
1) As the fungus becomes more branched, there is a higher chance of the branches being shredded by stirring.
2) Mutant fungi will spend energy (hence nutrients) on growth (making more branches) rather than synthesizing mycoprotein. In other words, energy and nutrients are wasted.
3) Mutant fungi could produce harmful, unwanted products
4) As mutant fungi grows, it could block the outlets and create internal pressure. This also makes it harder to feed in nutrients and extract product.
Mass of protein produced per day: 300 x 24 x (12/100) = 864 kg
4) Lizard question
Describe the graph of this lizard at rest (looked like a straight line): as temperature rises, the rate of oxygen consumption rises exponentially (since it's a log graph). At 40 degrees, the rate of oxygen consumption is 10 times greater than that at 15 degrees.
Measurements that need to be taken: respiratory quotient (as it is related to the carbon dioxide production and oxygen consumption). As RQ increases, so does the extent of anaerobic respiration (which is related to the oxygen debt)
Explain why oxygen demand increases by mentioning the mitochondria stuff: I pretty much wrote as ATP consumption increases, so does the ATP demand (hence production). Oxygen is the final hydrogen (and electron) acceptor in the oxidative phosphorylation process, so without it, aerobic respiration can't continue. The body will have to respire anaerobically to provide the energy required. This normally produces toxic substances and creates a large oxygen debt.
Explain the trend: (pretty much self-explanatory)
The lizard is a fast moving carnivore: It must run a lot to catch its prey, so its energy demands are high. A low oxygen debt implies that it respires aerobically for most of the time (which is healthier than anaerobic respiration)
How is it adapted: the developed lungs allow the maximum rate of oxygen absorption to be achieved which gets rid of the oxygen debt as soon as possible.
5) Why are the oocytes that have a polar body taken out: they are haploid and have developed enough to be used as gametes.
Explain why the oocytes shrink: both solutions A and B have a lower water potential than the oocyte, so water is lost by osmosis. The loss of water simulates a "contraction" decreasing the oocytes' volume
Which is better, A or B: B is better because more oocytes are effectively thawed, and there is a greater chance of successful fertilization (43% compared to 6%)
Advantage of freezing oocytes: they can be stored for later use/ they're long-lasting
6) Can't remember this question, sorry
7) The cross was pretty simple.
Definitions: sex-linked: the allele is found on one of the "sex" chromosomes (chromosome 23)
gene: a length of DNA which translates to one or more polypeptides
Why can't males be tortoiseshell: being tortoiseshell requires two alleles (black and orange). A male can only have one sex-linked allele since the other one must be a "Y" chromosome
Why is the 13-base deletion most harmful:
13 base deletion would cause a frame shift. All the codons that follow it would translate to completely different amino acids. This completely changes the (primary, secondary, and tertiary) protein structure. Also, a stop codon could be made which produces an incomplete protein.
Base substitutions have a chance of producing a degenerate codon (i.e. two codons which code for the same amino acid). In this case, the mutation is silent (and completely harmless). If this doesn't happen, then only one amino acid would be affected in which the damage is not as severe as a frame shift.
When 21 base pairs are deleted, that implies that 7 codons are deleted as well (since each codon is made up of 3 bases). There will not be a significant frame shift, and the following codons would code for the original amino acids. The only effect would be that 7 amino acids are deleted from the sequence.
8) Can't remember this question, sorry
9/10) I think we could have all just referred to the book for this one
Someone please check my answers!
1) A: palisade mesophyll cells; B: guard cell; C: air space
How does carbon dioxide enter: it enters through the stomata by diffusion where it will travel through the air spaces until it is absorbed by the (photosynthesizing) cells
Role of reduced NADP: it is used to reduce 3-PGA (along with two ATP) to G3P (PGAL).
2) (I think this was the GM mosquito one)
Why didn't the fever incidence increase immediately: disease could only be carried on female mosquitoes (similiar to Anopheles) and since only male mosquitoes were sent, the incidence did not rise immediately. I also wrote that since they were GM mosquitoes, they could have the "infection" gene removed while they were transformed anyways.
How was it positive feedback: tTA acts as an operator, so as the production/concentration of tTA increases, so does the expression of the gene that translates to it.
How does chemical A prevent death: it could act as an enzyme inhibitor preventing tTA from being metabolized into a harmful toxin. Or, it could react with tTA directly to neutralize it into a harmless product.
How to make 3 million GM mosquitoes: mate a GM mosquito with a non-GM female mosquito (from the wild) and place the eggs in a solution containing chemical A. Or, inject chemical A in all the embryos.
3) What is meant by continuous culture: (I think this is pretty much self-explanatory)
Explain why fungi must be replaced before reaching the mutant stage: I wrote 4 reasons for this one, as there were 4 marks:
1) As the fungus becomes more branched, there is a higher chance of the branches being shredded by stirring.
2) Mutant fungi will spend energy (hence nutrients) on growth (making more branches) rather than synthesizing mycoprotein. In other words, energy and nutrients are wasted.
3) Mutant fungi could produce harmful, unwanted products
4) As mutant fungi grows, it could block the outlets and create internal pressure. This also makes it harder to feed in nutrients and extract product.
Mass of protein produced per day: 300 x 24 x (12/100) = 864 kg
4) Lizard question
Describe the graph of this lizard at rest (looked like a straight line): as temperature rises, the rate of oxygen consumption rises exponentially (since it's a log graph). At 40 degrees, the rate of oxygen consumption is 10 times greater than that at 15 degrees.
Measurements that need to be taken: respiratory quotient (as it is related to the carbon dioxide production and oxygen consumption). As RQ increases, so does the extent of anaerobic respiration (which is related to the oxygen debt)
Explain why oxygen demand increases by mentioning the mitochondria stuff: I pretty much wrote as ATP consumption increases, so does the ATP demand (hence production). Oxygen is the final hydrogen (and electron) acceptor in the oxidative phosphorylation process, so without it, aerobic respiration can't continue. The body will have to respire anaerobically to provide the energy required. This normally produces toxic substances and creates a large oxygen debt.
Explain the trend: (pretty much self-explanatory)
The lizard is a fast moving carnivore: It must run a lot to catch its prey, so its energy demands are high. A low oxygen debt implies that it respires aerobically for most of the time (which is healthier than anaerobic respiration)
How is it adapted: the developed lungs allow the maximum rate of oxygen absorption to be achieved which gets rid of the oxygen debt as soon as possible.
5) Why are the oocytes that have a polar body taken out: they are haploid and have developed enough to be used as gametes.
Explain why the oocytes shrink: both solutions A and B have a lower water potential than the oocyte, so water is lost by osmosis. The loss of water simulates a "contraction" decreasing the oocytes' volume
Which is better, A or B: B is better because more oocytes are effectively thawed, and there is a greater chance of successful fertilization (43% compared to 6%)
Advantage of freezing oocytes: they can be stored for later use/ they're long-lasting
6) Can't remember this question, sorry
7) The cross was pretty simple.
Definitions: sex-linked: the allele is found on one of the "sex" chromosomes (chromosome 23)
gene: a length of DNA which translates to one or more polypeptides
Why can't males be tortoiseshell: being tortoiseshell requires two alleles (black and orange). A male can only have one sex-linked allele since the other one must be a "Y" chromosome
Why is the 13-base deletion most harmful:
13 base deletion would cause a frame shift. All the codons that follow it would translate to completely different amino acids. This completely changes the (primary, secondary, and tertiary) protein structure. Also, a stop codon could be made which produces an incomplete protein.
Base substitutions have a chance of producing a degenerate codon (i.e. two codons which code for the same amino acid). In this case, the mutation is silent (and completely harmless). If this doesn't happen, then only one amino acid would be affected in which the damage is not as severe as a frame shift.
When 21 base pairs are deleted, that implies that 7 codons are deleted as well (since each codon is made up of 3 bases). There will not be a significant frame shift, and the following codons would code for the original amino acids. The only effect would be that 7 amino acids are deleted from the sequence.
8) Can't remember this question, sorry
9/10) I think we could have all just referred to the book for this one
Someone please check my answers!