GCSE Biology OCR 21st century B4,5,6. 9th June 2017 Watch

Sbakth
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Hi, has anyone predicted any topics to come up in tomorrow's exam? Do you know any topics that I should definitely go over?
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NIONSD
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Unofficial markscheme:
1) memory= the ability to store information
b)cerebral cortex
c) through the use of new neural pathways. and by repeating her lessons she strengthens the pathways.
2)The layer of vegetable oil prevents air entering the mixture.
need help to complete the rest!!!

i know most of the answers but don't know the number. or the order they were in

6 markers
Sand dunes: (vague)
using a quadrant in different areas of the dunes and use an identification key to determine the plants. then count how many different species of plants there are in that area. Repeat again to increase confidence of theory.

Cystic Fibrosis:
the DNA contains bases of ACTG. the mRNA enters the nucleus and unzips the DNA. mRNA copies these bases but switches T with U. When the mRNA leaves the nucleus it goes to the ribosome. in the ribosome the bases are split into triplets and each one codes for an amino acid. If the order of the bases are wrong, the order of the copy is wrong which causes the wrong amino acid to be produced. the wrong order of amino acids creates a different protein.

Starfish:
I don't know if i was correct so i need help.
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username3167456
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Memory (2) I talked about forming neural pathways and the ability to recall memories. I also talked about how it enables us to remember how to perform skills.
Starfish (6) I basically defined how the human nervous system works and then compared it to the starfish. Similarities; the receptor that detects the stimuli, I said it was sort of similar that there is a nerve that links the receptor to the central nerves (radial nerve in starfish, sensory neuron in humans), both have some form of relay (spinal cord and the ring nerve thing), both have reflexes. Differences; humans have a brain which can override the reflex, humans have a spinal cord, humans can make conscious choices, starfish only exhibit simple reflexes.
Transport in plant roots was 1 mark, it was osmosis I believe.

There was 2 marks on cystic fibrosis mucus, I first defined osmosis and said it was sticky because the calcium/water was unable to leave the cell like normally they can, to enter the mucus? I think I said that the calcium is in the water, hence its osmosis, but cant remember or know if that is right.

Ecstacy and PTSD conclusion (1) Ecstacy, when used in conjunction to regular therapy, is more effective than therapy alone.
Scientists being sure of the conclusion (2) I know I mentioned other scientists would need to repeat, and explain the mechanism linking the ecstacy to better recovery.

Calculations: 0.0012%
9000 people with the specific gene?
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Silhouette_A
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(Original post by samwesttt)
Memory (2) I talked about forming neural pathways and the ability to recall memories. I also talked about how it enables us to remember how to perform skills.
Starfish (6) I basically defined how the human nervous system works and then compared it to the starfish. Similarities; the receptor that detects the stimuli, I said it was sort of similar that there is a nerve that links the receptor to the central nerves (radial nerve in starfish, sensory neuron in humans), both have some form of relay (spinal cord and the ring nerve thing), both have reflexes. Differences; humans have a brain which can override the reflex, humans have a spinal cord, humans can make conscious choices, starfish only exhibit simple reflexes.
Transport in plant roots was 1 mark, it was osmosis I believe.

There was 2 marks on cystic fibrosis mucus, I first defined osmosis and said it was sticky because the calcium/water was unable to leave the cell like normally they can, to enter the mucus? I think I said that the calcium is in the water, hence its osmosis, but cant remember or know if that is right.

Ecstacy and PTSD conclusion (1) Ecstacy, when used in conjunction to regular therapy, is more effective than therapy alone.
Scientists being sure of the conclusion (2) I know I mentioned other scientists would need to repeat, and explain the mechanism linking the ecstacy to better recovery.

Calculations: 0.0012%
9000 people with the specific gene?
Chloride not calcium
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username3167456
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(Original post by Jayden_Marks)
Chloride not calcium
Thats what i meant, thanks
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tanishaevans
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(Original post by samwesttt)
Memory (2) I talked about forming neural pathways and the ability to recall memories. I also talked about how it enables us to remember how to perform skills.
Starfish (6) I basically defined how the human nervous system works and then compared it to the starfish. Similarities; the receptor that detects the stimuli, I said it was sort of similar that there is a nerve that links the receptor to the central nerves (radial nerve in starfish, sensory neuron in humans), both have some form of relay (spinal cord and the ring nerve thing), both have reflexes. Differences; humans have a brain which can override the reflex, humans have a spinal cord, humans can make conscious choices, starfish only exhibit simple reflexes.
Transport in plant roots was 1 mark, it was osmosis I believe.

There was 2 marks on cystic fibrosis mucus, I first defined osmosis and said it was sticky because the calcium/water was unable to leave the cell like normally they can, to enter the mucus? I think I said that the calcium is in the water, hence its osmosis, but cant remember or know if that is right.

Ecstacy and PTSD conclusion (1) Ecstacy, when used in conjunction to regular therapy, is more effective than therapy alone.
Scientists being sure of the conclusion (2) I know I mentioned other scientists would need to repeat, and explain the mechanism linking the ecstacy to better recovery.

Calculations: 0.0012%
9000 people with the specific gene?
how did you get 0.0012%?
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tanishaevans
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what did everyone get for the serotonin question? i put C A E B D but then changed it to C A B E D
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Deliciate
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(Original post by tanishaevans)
what did everyone get for the serotonin question? i put C A E B D but then changed it to C A B E D
Can't remember. Do you vaguely remember what the letters stand for?
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username3167456
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(Original post by tanishaevans)
how did you get 0.0012%?
3 genes out of 250 000, so (3/250 000)
(3/250 000)*100 = 0.0012%
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menna123
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(Original post by tanishaevans)
what did everyone get for the serotonin question? i put C A E B D but then changed it to C A B E D
Can't remember the letter order but it was 1) serotonin goes back to first neutron 2 concentration of serotonin increases in gap 3) more serotonin on next neuron membrane 5) more impulses generated
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menna123
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(Original post by samwesttt)
3 genes out of 250 000, so (3/250 000)
(3/250 000)*100 = 0.0012%
I did that but kept it in standard form
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(Original post by tanishaevans)
what did everyone get for the serotonin question? i put C A E B D but then changed it to C A B E D
I don't remember putting C A B E D; C A E B D looks more familiar.
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tanishaevans
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(Original post by samwesttt)
3 genes out of 250 000, so (3/250 000)
(3/250 000)*100 = 0.0012%
i could not figure out how to do it >_< i was trying to do something like this but doing 250000/3 instead, makes sense now. ugh.
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menna123
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For the question of faulty DNA , did you have to mention how protein is made? I just talked about the amino acid coding and the fact that it codes for protein and described the structure of DNA as the question said 'describe DNA and why a mutation would cause a faulty protein being made'
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tanishaevans
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(Original post by menna123)
Can't remember the letter order but it was 1) serotonin goes back to first neutron 2 concentration of serotonin increases in gap 3) more serotonin on next neuron membrane 5) more impulses generated
ok, i'm pretty sure that's what i put. i was confused w/ the order of "concentration of serotonin increases" and "more serotonin on next neurone" if that's right then i'm sure CABED is the correct letter order! thanks
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(Original post by menna123)
For the question of faulty DNA , did you have to mention how protein is made? I just talked about the amino acid coding and the fact that it codes for protein and described the structure of DNA as the question said 'describe DNA and why a mutation would cause a faulty protein being made'
I assume that you have to describe how a protein is made via the mRNA and in the cytoplasm by ribosomes. However, the main idea is that you have to say that the faulty order of bases will code for the sequence of amino acids which therefore makes a faulty protein. You should be good if you described the mRNA process (although I doubt it has to be in too much depth). The examiners report highlighted how candidates fail to use the terms 'sequence' and 'amino acids' in their answers so they wanted to test our ability there.
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tanishaevans
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(Original post by menna123)
For the question of faulty DNA , did you have to mention how protein is made? I just talked about the amino acid coding and the fact that it codes for protein and described the structure of DNA as the question said 'describe DNA and why a mutation would cause a faulty protein being made'
i didn't talk about the ribosome or mRNA or anything, i just wrote about the two strands being coiled together in double helix shape and being made up of nucleotides and how they're attached by the bases, thymine adenine cytosine guanine A-T C-G and if the order is changed the protein wont code for what it was supposed to code for or something. anyone know if this is right?

edit* also spoke about triplets coding for one amino acid and them being joined to make a protein but not where it happens or how
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menna123
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I said something on these lines:
DNA is a double helix of paired bases which always pair up in the same way A-T C-G, the order of bases in DNA (tripled code) code for one amino acid. Amino acids are joined together to make proteins, each amino acid has a unique set of three bases and each protein requires a particular order/sequence of amino acids. The change of the base order means that a different amino acid is coded for and so therefore a different/faulty protein is made as different proteins have different sequences of amino acids.
I think that would be worth 2 marks lol
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menna123
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(Original post by tanishaevans)
i didn't talk about the ribosome or mRNA or anything, i just wrote about the two strands being coiled together in double helix shape and being made up of nucleotides and how they're attached by the bases, thymine adenine cytosine guanine A-T C-G and if the order is changed the protein wont code for what it was supposed to code for or something. anyone know if this is right?

edit* also spoke about triplets coding for one amino acid and them being joined to make a protein but not where it happens or how

Same!
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Ghostlythinking
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Does anyone know the answers to the tick box questions where there were 2 sets of tick boxes in a row and were about amino acids and stuff?

The first answers were either cellulose and starch or nitrates and glucose but I don't know which so could somebody tell me what they got?
And the second tick box was proteins
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