Edexcel 6BIO2 ~ 3rd June 2013 ~ AS Biology

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Reply 2020

ALevel96

Original post by Swaany

Guys, i took pics of the copy of the paper from my teacher. Will upload it tomorrow, please be patient with me :smile:

When will you upload the paper?

Reply 2021

fadyfox95

Original post by ALevel96

When will you upload the paper?

now it's tomorrow dude, hope u didn't forget to upload, we are counting on u.

Reply 2022

Alexandra82

Original post by jcao03

I don't think there was a question on ferrets about genetic variation and captive breeding! It was the question before I think. :confused:

I'm pretty sure there was a 5 marker saying "explain how captive breeding is used to create genetic diversity in the ferret population" or something similar to that...

Reply 2023

SKK94

Original post by Alexandra82

I'm pretty sure there was a 5 marker saying "explain how captive breeding is used to create genetic diversity in the ferret population" or something similar to that...

Yup, there was; something about many zoos taking in endangered ferrets for captive breeding etc etc

Reply 2024

Swaany

Hi guys, as promised here is the June 2013 paper :smile:

(edited 10 years ago)

Reply 2025

Swaany

Reply 2026

Swaany

enjoy!

Reply 2027

mynameisntbobk

Original post by Swaany

Hi guys, as promised here is the June 2013 paper :smile:

Original post by Swaany

enjoy!

thank you so much!!!! :biggrin:

I'll rep you when I get on my laptop!

Thank you very much!

we need some one to make a markscheme please.

Reply 2030

mynameisntbobk

Original post by fadyfox95

we need some one to make a markscheme please.

I don't mind doing this one, but it'll have to be tomorrow if people don't mind..

Reply 2031

fadyfox95

Original post by mynameisntbobk

I don't mind doing this one, but it'll have to be tomorrow if people don't mind..

that would be great.

Reply 2032

ALevel96

Ill do one in about 15 mins

Reply 2033

Swaany

Original post by mynameisntbobk

thank you so much!!!! :biggrin:

I'll rep you when I get on my laptop!

haha thankss :smile:

Reply 2034

ALevel96

1a) C
b) D
c) A
d) D
e) C
f) D
g) D
h) C

(edited 10 years ago)

Reply 2035

RoryTinker

SER is present in animal and plant cells I think

Reply 2036

CoolRunner

Original post by ALevel96

1a) C
b) D
c) A
d) D
e) C
f) D
g) C
h) C

G is wrong. it is D. sER is found in both animal and plant cell, you said C (meaning plant cell only). Everything else I did :smile:

Reply 2037

mynameisntbobk

Original post by RoryTinker

SER is present in animal and plant cells I think

It is

Reply 2038

ALevel96

2a) The acrosome swells, fusing with the cell surface membrance. Acrosin; a hyrdolytic enzyme that digests the zona pellucida of the ovum is released via exocytosis.
The sperms haploid nucleus is then able to enter the ovum cytoplasm.
following this there is an increase in Ca2+ in the cytoplasm resulting in a thickening of the zona pellucida.
This prevents further sperm nuclei from entering and hence ensuring the ovum is fertilised by a single haploid nuclei.

b) During meiosis Independent assortment and crossing over occurs.
Independent assortment is the random assortment of chromosomes to different cells. This ensures four unique haploid cells are produced per cycle. Crossing over occurs when different versions of the same gene are exchanged bewteen adjacent sister chromatids during metaphase. For these reasons a large genetic diversity occurs.

c (i) The temperature was kept constant as the temperature determines the rate at which proteins are made. If the temperature is changed between trials the results obtained will be invalid since the rate of formation of proteins and hence the rate at which the tube grows.

c(ii) Generally as the concentration of Methylpurine increases the mean growth length of the pollen tube decreases. There is however an increase between 0.0000 and 0.0001 moldm^-3 this suggests that 0.0001 of methylypurine is the optimum concentration for pollen tube growth. Third mark will be to quote values i.e an ...% decrease in pollen length between two concentrations.

C(iii) mRNA is translated into proteins. If methylypurine inhibits mRNA systhesis, then the mRNA cannot be translated to produce proteins. The proteins determine the ultrastructure of the cell and hence the length of it.