1.
State what is meant by the genetic code.
[1 mark]
- triplet, degenerate, non-overlapping, universal
JD SCIENCE
Genetics, variation and gene technology
Indicative marking points. Award marks for equivalent scientific or mathematical wording. Do not issue this sheet with the student worksheet.
2.
State what is meant by transcription.
[1 mark]
- DNA → mRNA in the nucleus
3.
State what is meant by translation.
[1 mark]
- mRNA + tRNA + ribosome → polypeptide
4.
State what is meant by a mutation.
[1 mark]
- change in DNA base sequence
5.
State what is meant by meiosis.
[1 mark]
- two divisions, haploid gametes, variation
6.
State what is meant by natural selection.
[1 mark]
- differential survival and reproduction
7.
State what is meant by speciation.
[1 mark]
- new species form when gene flow stops
8.
State what is meant by taxonomy.
[1 mark]
- classification into domain to species
9.
State what is meant by biodiversity.
[1 mark]
- variety of species, genetic and habitat
10.
State what is meant by an antibody in immunity.
[1 mark]
- specific protein from plasma cells
11.
Devon is asked about the genetic code in a Edexcel Biology paper.
(a) [2 marks]
- codons code for amino acids
(b) [3 marks]
- start and stop
12.
Devon is asked about transcription in a Edexcel Biology paper.
(a) [2 marks]
- RNA polymerase
(b) [3 marks]
- template strand
13.
Devon is asked about translation in a Edexcel Biology paper.
(a) [2 marks]
- anticodon pairing
(b) [3 marks]
- peptide bonds
14.
Devon is asked about a mutation in a Edexcel Biology paper.
(a) [2 marks]
- substitution, insertion, deletion
(b) [3 marks]
- frameshift is usually worse
15.
Devon is asked about meiosis in a Edexcel Biology paper.
(a) [2 marks]
- crossing over and independent assortment
(b) [3 marks]
- fertilisation adds more variation
16.
Devon is asked about natural selection in a Edexcel Biology paper.
(a) [2 marks]
- allele frequencies change
(b) [3 marks]
- directional or stabilising
17.
A DNA sequence has 600 bases. Maximum amino acids
[3 marks]
- Final answer: 200
18.
Chi-squared: 3:1 expected of 80 plants. Expected recessive
[3 marks]
- Final answer: 20
19.
Index of diversity N(N−1)/Σn(n−1). If N=10 and Σ=12, D
[3 marks]
- Final answer: 7.5
20.
Heterozygous cross Aa × Aa. Probability of aa
[3 marks]
- Final answer: 0.25
21.
A gene pool has p=0.8. If HWE, frequency of heterozygotes
[3 marks]
- Final answer: 0.32
22.
A 4-base sequence has 4⁴ possible combinations
[3 marks]
- Final answer: 256
23.
Devon carries out a Edexcel-style required practical linked to genetic information and variation. This is a typical Edexcel required-practical style question.
(a) [2 marks]
- Independent: the independent variable for this topic
- Dependent: the measured outcome
(b) [2 marks]
- keep all other variables constant
- so the test is fair / only one variable is changed
(c) [2 marks]
- repeat and calculate a mean / use a tighter method
24.
Devon carries out collecting valid data for genetic information and variation. This is a typical Edexcel required-practical style question.
(a) [2 marks]
- Independent: a chosen factor
- Dependent: a quantitative measurement
(b) [2 marks]
- calibrated instrument
- so the test is fair / only one variable is changed
(c) [2 marks]
- systematic error from zero error
25.
Devon carries out drawing a graph for genetic information and variation. This is a typical Edexcel required-practical style question.
(a) [2 marks]
- Independent: x-variable
- Dependent: y-variable
(b) [2 marks]
- same scale / same apparatus
- so the test is fair / only one variable is changed
(c) [2 marks]
- not drawing a line of best fit through the trend
26.
Devon carries out evaluating a method about genetic information and variation. This is a typical Edexcel required-practical style question.
(a) [2 marks]
- Independent: method change
- Dependent: precision / accuracy
(b) [2 marks]
- same sample size
- so the test is fair / only one variable is changed
(c) [2 marks]
- too few repeats
27.
Compare the genetic code with transcription.
[4 marks]
- triplet, degenerate, non-overlapping, universal
- DNA → mRNA in the nucleus
- give one linked difference
28.
Compare transcription with translation.
[4 marks]
- DNA → mRNA in the nucleus
- mRNA + tRNA + ribosome → polypeptide
- give one linked difference
29.
Compare translation with a mutation.
[4 marks]
- mRNA + tRNA + ribosome → polypeptide
- change in DNA base sequence
- give one linked difference
30.
Compare a mutation with meiosis.
[4 marks]
- change in DNA base sequence
- two divisions, haploid gametes, variation
- give one linked difference
31.
Apply your knowledge of speciation to this situation: allopatric vs sympatric
[3 marks]
- allopatric vs sympatric
32.
Apply your knowledge of taxonomy to this situation: binomial names
[3 marks]
- binomial names