OCR 21st century B456 2017

Could someone please post an unofficial mark scheme for today's paper. Much appreciated.

In the meantime we could post answers we remember. I'll try but I don't remember question numbers.

Cerebral cortex.
0.0012%.
Memory is the ability to store and retrieve information.
Watch the child and do genetic tests.

Reply 2

NIONSD

1

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.

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.

Reply 3

DD2508

14

For the percentage question, would it be okay if I wrote my answer in standard form??

Reply 4

aaronbrooks17

2

Original post by DD2508

For the percentage question, would it be okay if I wrote my answer in standard form??

I did the same, 1.2 x 10^-3 I think

Reply 5

Mathushan24

OP

2

What was the starfish question answer. Something like it's nervous system. I talked about the axon and cytoplasm of a neurone but I realised it said nervous system so it has to be about the CNS right???

Original post by aaronbrooks17

I did the same, 1.2 x 10^-3 I think

Reply 6

Shadow_Messiah19

8

Original post by NIONSD

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.

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.

For the starfish 6 marker I literally stated how the CNS and PNS works in humans, how they both are seperate but work together. Then for the starfish I talked about how it doesnt involve a brain to process the information, acting more as a reflex arc than a nervous system, and that was the similarity, another similarity i stated was that we both share receptors to detect change in stimuli.

Reply 7

aaronbrooks17

2

Basically outlined the CNS, with reference to PNS, and compared the eyespot with our receptors, but mentioned how our receptors can detect any stimuli. Compared how we have billions of nerve pathways, but the starfish has 5. I said that the ring at the centre could act as some kind of processing centre, but ours is so much more complex. Then a bit about complexity of the human system etc.