Biology 7401/1 Paper 1 Mark scheme with " Question,, Marking Guidance ,,Mark & Comments"
Question Marking Guidance Mark Comments 01.1 Feature Bacterium Human immunodeficiency virus (HIV) particle RNA Cell wall Enzyme molecules Capsid 2 1 mark for each correct vertical column 01.2 1. (Complementary) nucleotides/bases pair OR A to T and C to G; 2. DNA polymerase; 3. Nucleotides join together (to form new strand)/phosphodiester bonds form; 3 1. & 3. Ignore ‘(DNA polymerase) forms base pairs/nucleotide pairs’ If clearly writing rote answer about DNA replication 2 max e.g. helicase or separating strands 01.3 1. DNA double stranded/double helix and mRNA single-stranded; 2. DNA (very) long and RNA short; 3. Thymine/T in DNA and uracil/U in RNA; 4. Deoxyribose in DNA and ribose in RNA; 5. DNA has base pairing and mRNA doesn’t/ DNA has hydrogen bonding and mRNA doesn’t; 6. DNA has introns/non-coding sequences and mRNA doesn’t; 3 max Contrast requires both parts of the statement 2. Accept ‘RNA shorter’ or ‘DNA bigger/longer’ 4. R Deoxyribonucleic/ ribonucleic acid Ignore ref. to histones Ignore ref. to helix and straight chain alone 6.Ignore ref to splicing
Written for
- Institution
- Biology 7401/1
- Course
- Biology 7401/1
Document information
- Uploaded on
- April 3, 2024
- Number of pages
- 15
- Written in
- 2023/2024
- Type
- Exam (elaborations)
- Contains
- Questions & answers
Subjects
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biology 74011 paper 1 mark scheme
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mark scheme instructions to examiners 1 general
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011 feature bacterium human immunodeficiency vi
