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Edexcel GCE Biology Unit 5 6BI05 June 2013

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Original post by Mjwilson1988

I think I know where you're going wrong buddy, the question says:

"Myosin molecules can generate a force of 1.7 × 10–6 N per million molecules when they change shape."

Therefore you've got to do the calculation (3.5x10-3) / (1.7x10-6) then all that multiplied by 1,000,000 which gives you '2,058,823,529' or 2,059,000,000 (which is 2059 million)

Right thanks, but i cant believe the mark scheme didn't have 1 million anywhere.

Also dose not the 1.7 × 10–6 force created imply its made by that 'per million'?

(edited 10 years ago)

Reply 861

Hannnnah

The amount of effort and revision i have put into this exam better pay off! :s-smilie:

Reply 862

Mollymod

Original post by Mjwilson1988

Exactly, but you don't need to use the whole trace scale to work it out, if I saw that I had 3 beats in 5 seconds, I could easily get an answer of (60/5) x 3 = 36bpm.

Or if I had 7 beats in 3 seconds I'd do (60/3) x 7 = 140bpm (this person is running for their life!

Sweet. Many thanks.

Reply 863

jojo1995

you see a control testube in the respirometer practical, would you use glass beads or no organisms at all ? please

Reply 864

bubblegummer

Guys, how do you describe the production of genetically modified organisms (for plants, animals and microorganisms) by the use of drugs? could you please explain it to me. thanks in advance :smile:

Also i'm wondering is anyone here taking Chem 5 on wednesday? :confused:

(edited 10 years ago)

Reply 865

Mjwilson1988

Original post by jojo1995

you see a control testube in the respirometer practical, would you use glass beads or no organisms at all ? please

Beads with the same mass as the woodlice.

Reply 866

Lujain Al Omari

Original post by jojo1995

you see a control testube in the respirometer practical, would you use glass beads or no organisms at all ? please

I'd choose glass beads, because there WOULD be something. And to make it a convincing control, use glass beads of the same number and size

Reply 867

Sly1

Original post by bubblegummer

Anyone here taking Chem 5 on wednesday? :confused:

F324 yes

Reply 868

Mjwilson1988

Original post by Volltorb

Right thanks, but i cant believe the mark scheme didn't have 1 million anywhere.

Also dose not the 1.7 × 10–6 force created imply its made by that 'per million'?

No, that is just the number that has been registered, fairly unfortunate that it is the same as million! if you want to know how much force per one molecule of myosin it would be 1.7 x 10 -12, then you could divide 3.5x10-3 by that and get the same answer.

Reply 869

MY.

For naked mole rat do we need to know how blood clots form ?

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Reply 870

jojo1995

Original post by Mjwilson1988

Beads with the same mass as the woodlice.

thank you guys :smile:

is this for making sure pressure has no effect on the experiment ? aLso,, what cause the pressure, is it the organoism?

Original post by Lujain Al Omari

I'd choose glass beads, because there WOULD be something. And to make it a convincing control, use glass beads of the same number and size

(edited 10 years ago)

Reply 871

thetularula

Original post by Hannnnah

The amount of effort and revision i have put into this exam better pay off! :s-smilie:

I feel the same way - I dislike how half of it is just luck of the paper though. ):

Reply 872

flower123456

Original post by bubblegummer

Also i'm wondering is anyone here taking Chem 5 on wednesday? :confused:

Yeah I am

edexcel unit 5. Soo hard revising for both exams

Reply 873

flower123456

Original post by MY.

For naked mole rat do we need to know how blood clots form ?

Posted from TSR Mobile

They may bring it up so its worth going over it.

Reply 874

Mjwilson1988

Original post by bubblegummer

Guys, how do you describe the production of genetically modified organisms (for plants, animals and microorganisms) by the use of drugs? could you please explain it to me. thanks in advance :smile:

Also i'm wondering is anyone here taking Chem 5 on wednesday? :confused:

I'm taking Chem 5 on Wednesday, that one isn't as frightening as Bio 5 though!

Also, in reply to your question, did you mean the production of Drugs by using GMOs (Plants, Microorganisms and Animals)?

Microorganisms -

First isolate a healthy gene which codes for the protein (drug) you wish to make, such as the human insulin gene. (You can link this with the Human Genome Project, which has helped us map out all the healthy genes for each protein etc).

Amplify the gene using the Polymerase Chain Reaction, to produce many copies of the gene.

Insert the Gene into a Plasmid (circle of DNA commonly found in Bacteria).

Modify the Bacteria with the plasmids (This step is awkward because the genes won't always take, however a good way of identifying which bacteria have taken up the genes is to also code a gene for antibiotic resistance too and insert that into the plasmid along with the gene for Insulin, then treat the bacteria with Antibiotics, the ones that survive are likely to be the ones who have taken the plasmid, so are the bacteria you want.)

Place the bacteria in a vat/storage whatever thing you wanna use to allow them to reproduce. They will now begin to produce the protein (drug) you want.

Advantages include producing large amounts of industrial enzymes cheaply and quickly, also Insulin made from GMOs which have human genes mean that the insulin made will be much more compatible with humans that, say, using Animal Insulin.

Disadvantages are that there is a risk of the bacteria getting into the general population (this seems to get you a mark, but if we're being realistic, this would never happen because scientist are smart enough to have made these GMOs unable to live outside the lab!), and playing god is ethically questionable!

Plants:

Insert therapeutic gene into Bacteria/Virus to be used as a Vector and infect the plant with this vector.

The pathogen will implant the genetic material into the plants genome for transcription. (Typically, they modify a bacteria which gives plants a type of 'plant cancer' then harvest the tumor cells because they know that these cells carry the gene for the drug).

Using these harvested cells a new plant is grown (remember how all plant cells are Totipotent and can grow and whole new plant?)

Now the plant will produce the drug in its fruit etc.

Advantages being that fruit doesn't require a lot of specialised storage, and (example bananas) can be grown in parts of the world that really need the drug and can be administered without specialist help (eating the Banana gives a dose of the drug, how special!). Also, when we're talking about just modifying plants for other things, you get massive yields and more resistance to predators and such.

Disadvantages are that some people fear that cross pollination could occur and these genes are spread across wild species which is not likely as most plants that are Genetically modified are also sterile so to prevent this, however making them sterile means they won't reproduce each yeah, thus a new supply has to be bought from the drug company which is expensive! Also, people get all freaky about eat GM crops, god knows why though.

Animals:

Genes coding for the desired protein are injected into a fertilised animal egg and this egg is implanted, so that the egg is carried to term and the animal produced has a genome coding for this protein.

When this animal comes of age, and starts producing milk (for example) the protein will also be produced in the milk, making this milk a source for this drug. Companies can then sell the milk as is (with the drug in it) or purify the drug by separating it from the milk.

Advantages of modifying animals are that, once you have modified the animal, it can reproduce and you can produce a herd or animals all able to produce the drug.

Disadvantages is that the products from the animals are very costly typically, which can lead to a two tier system (poor people can't afford so don't get treatment, where rich people can). Also, playing God again, bla bla.

Hope this helps, this is a heck of a post though.... sorry about that!

Edit: In my flurry of typing I made some awful spelling mistakes!

(edited 10 years ago)

Reply 875

Mjwilson1988

Original post by jojo1995

thank you guys :smile:

is this for making sure pressure has no effect on the experiment ? aLso,, what cause the pressure, is it the organoism?

The pressure difference is just made by the reduction of O2, which is been taken in by the organism. As air decreases, the liquid moves to try to counter act the pressure reduction.

The control tube is there just to try to make sure that the movement of the liquid is because there is something living in Tube A, rather than just having anything in there.

Reply 876

anaab.naeem

Can someone help me answer these for the pre-release:

1. Naked mole rats show various adaptations to their particular environment Given an example of these adaptations exhibited by these animals.
Behavioural adaptation:
Physiological adaptation:
Anatomical adaptation:
2. Give two examples of features that help thermoregulation in most mammals that are reduced or absent in naked mole rats and explain how each operates to help achieve thermoregulation.
3. Give one advantage and one disadvantage in being poikilothermic in comparison to homeothermy.
4. The non-reproductive individuals in eusocial animals do not directly transfer their genes to offspring. In spite of this there must still be a genetic advantage in being eusocial – suggest what this must be.
5. What evidence would scientists look for when searching for evidence of heart disease in naked mole rats?
6. Suggest how extra molecules attaching to proteins might affect their structure and function.
7. Suggest what processes would be altered by the cancer causing genes.
8. Describe the techniques that would be used to insert the cancer causing genes into the cells of the rats.
9. How might the immune system of immune compromised mice differ from normal mice?
10. Name the process by which cells replicate (p14) and describe the events that take place in the main events of this process.
11. Explain how transcription factors bring about expression of a gene (p24)
12. Describe the procedures of a potential new anti-cancer therapy would have to go through before it could be licensed as a drug.
13. Explain how impulses would be transmitted from the pain receptors of a rodent to its central nervous system.
14. What is the sequence of neurones impulses would pass through, to result in withdrawing a hand from a hot stove?
15. Describe the responses that humans would show if they were breathing air with 5% carbon dioxide, and explain how these responses are brought about.
16. A brain deprived of oxygen will lead to a brain deprived of ATP/energy. Describe the role of oxygen in the production of ATP.
17. Explain how populations of naked mole rats have evolved to be resistant to hypoxia.
18. Use of modern scanning techniques has transformed our understanding of the localisation of function in the brain. Describe how FMRI can be used to study brain function and compare this with early techniques that were used to investigate brain function.
19. From p47 why are the new prosthetics being developed at UCL less likely to damage tissues, and why is there a problem that must be overcome with these prosthetics.
20. The queen prevents non-breeders becoming reproductive by altering the hormonal balance in the non breeders. Compare and contrast the ways in which this kind of communication differs from nervous communication.
21. Describe the techniques and procedures that would be used to produce a DNA fingerprint from a naked mole rat
22. Suggest why out-breeding is likely to increase the long term survival of the naked mole rat populations.
23. In the suppression of breeding by the queen identify
(a) the stimulus
(b) the effector
(c) the response for the non-breeding males
24. From one ethical viewpoint discuss whether some of the experiments carried out on naked mole rats can be justified.