AQA GCSE Biology B2 Unofficial Markscheme 2017

Q1. a) i) Where are epithelial cells located?
A. They line the insides of the lungs, the gastrointestinal tract, the reproductive and urinary tracts, and make up the exocrine and endocrine glands. Skin may be accepted

Q1. a) ii) Label 1 and 2 from the diagram.
A. 1. Cell membrane (not cell wall) 2. cytoplasm

Q1. a) iii) What do ribosomes do?
A. Protein synthesis

Q1 b?) What is diffusion?
A. Where particles move/ diffuse from high concentration to low concentration to make them more equal

Q2) How should a student investigate the distribution of a plant A using a quadrat and a soil pH measurer?
A.
*Quadrat placed randomly, non biased location, and student counts amount of the plant in a section, then takes the soil pH.
*Does this in multiple locations to see the distribution of these plants, comparing them to pH levels.
*Record results in table and plot on graph to see correlation
*Can be repeated so results are accurate

What didn't everyone get for the calculation question?

for the speciation question (last one) I talked about:

- geographical isolation
- natural selection (survival of the fittest)
- mutilation (because of that)
- speciation (they can't interbreed)
- these changes caused speciation
- they were still similar as they evolved from same species but few changes are due to the environment they are in.

Something along those lines.

For epithelial I got the answer as the stomach. For the calculation I got 50% but I don't think it's correct. In the last question about the birds I put stuff down like genetic variation, environmental change, natural selection, how the birds have been isolated and that they can't interbreed successfully anymore. In the genetic diagram question I got 1/4 chances for the child to have the AKU or something.

I got 50% and stomach. The tickbox was protein synthesis, the one on chromosomes? The first part of question 6 literally came up years before, and the mark schemes said an allele can be described as a "type of a certain gene" or a certain gene form.

I did the gentic diagram in pencil does anyone know if this is still valid as I did get 1/4

What about sampling?