1.
State what is meant by the genetic code.
[1 mark]
- triplet, degenerate, non-overlapping, universal
JD SCIENCE
Module 4 Biodiversity, evolution and disease
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.
Grace is asked about the genetic code in a OCR Biology paper.
(a) [2 marks]
- codons code for amino acids
(b) [3 marks]
- start and stop
12.
Grace is asked about transcription in a OCR Biology paper.
(a) [2 marks]
- RNA polymerase
(b) [3 marks]
- template strand
13.
Grace is asked about translation in a OCR Biology paper.
(a) [2 marks]
- anticodon pairing
(b) [3 marks]
- peptide bonds
14.
Grace is asked about a mutation in a OCR Biology paper.
(a) [2 marks]
- substitution, insertion, deletion
(b) [3 marks]
- frameshift is usually worse
15.
Grace is asked about meiosis in a OCR Biology paper.
(a) [2 marks]
- crossing over and independent assortment
(b) [3 marks]
- fertilisation adds more variation
16.
Grace is asked about natural selection in a OCR 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.
Grace carries out a OCR-style required practical linked to genetic information and variation. This is a typical OCR 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.
Grace carries out collecting valid data for genetic information and variation. This is a typical OCR 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.
Grace carries out drawing a graph for genetic information and variation. This is a typical OCR 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.
Grace carries out evaluating a method about genetic information and variation. This is a typical OCR 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