Year 12s: what will be the first way you research your future options? >>

UNOFFICIAL MARK SCHEME Biology B3 Edexcel 2016

starting a new mark scheme post your answers below

1 a) Microalgae grow at a faster rate
b)carbon dioxide
c)
d)
i) Maintain an optimum pH
ii) Maintain an optimum pH

2 a) 53%
b) glucose enter the blood through a network of capillaries
against the concentration gradient

3 a) thickening the uterus wall
b) the egg was fertilised
c) High levels of progesterone inhibit the release of LH and FSH
corpus leutem releases progesterone
progesterone maintains the lining of the uterus

6 marker on fossils

Leakey discovered homo habilus and homo erectus
carbon-14 dating
stratigraphy
study tools found with the fossil
more complex tools means a larger brain
compare fossil to other fossil

6 marker on Toxin gene advantages and disadvantages

•

increased crop yield

•

more food

disadvantages

•

negative impact on the food chain

•

may lead to pests that are resistant to the toxin

•

weeds may get the gene to create the toxin which decreases crop yield

•

GM plants are expensive

•

reduction in biodiversity

(edited 7 years ago)

Reply 1

ART2033

For the one about high levels of progesterone on the graph I wrote pregnancy do you think this would get a mark?

Yeah definitely

What is the answer to the question that asked about the hormone or something? It was a one marker and one of the mid early questions in the paper (You had to write the answer yourself, it wasn't a 4 way selection choice).