CCEA A-Level Life and Health Sciences 0008
Experimental Techniques
Human Body Systems
Physical Chemistry in Industrial Processes
Brain ScienceDouble Award
Material ScienceDouble Award
Medicine, Drugs and Clinical TrialsDouble Award
Scientific Method, Investigation, Analysis and Evaluation
Organic Chemistry
Medical PhysicsA2 option
Sound and LightA2 option
Genetics, Stem Cell Research and CloningA2 option
MicrobiologyDouble Award
Oral Health and DentistryDouble Award
Histology and PathologyDouble Award
Analytical Chemistry TechniquesDouble Award
Enabling TechnologyDouble Award
Genetics, Stem Cell Research and Cloning
RNA, genes and the triplet code
- 3 things to know
- A2 5
Overview
RNA against DNA, messenger, transfer and ribosomal RNA, genes, loci and polypeptides, the triplet code with a worked base count, mutations and new alleles, substitutions and frameshift deletions.
What you need to know
Answer each one before you reveal it.
How does the structure of RNA differ from that of DNA?
What is messenger RNA, and what does it do?
Questions from this subtopic
Each one with the model answer underneath.
- 1
How does the structure of RNA differ from that of DNA?
Model answer
RNA is usually a single, shorter strand containing the sugar ribose. RNA has the base uracil in place of thymine.
- 2
What is messenger RNA, and what does it do?
Model answer
Messenger RNA is a single-stranded copy of a gene made during transcription in the nucleus. The mRNA carries the code to the ribosomes as a series of three-base codons.
- 3
Describe the structure and role of transfer RNA.
Model answer
Transfer RNA is a short strand folded into a clover-leaf shape with an anticodon of three bases. A specific amino acid attaches at one end and is carried to the ribosome.
- 4
What is the role of ribosomal RNA?
Model answer
Ribosomal RNA combines with proteins to form ribosomes. A ribosome holds the mRNA and tRNA in place while amino acids are joined in translation.
- 5
What is a gene?
Model answer
A gene is a section of DNA with a specific sequence of bases. The sequence carries the code for a particular polypeptide.
- 6
What is a polypeptide, and how does it relate to a protein?
Model answer
A polypeptide is a chain of amino acids joined by peptide bonds. A protein is made of one or more polypeptides folded into a particular shape.
Other ways to work this
The same content, four other ways.
What is inside Levo
Six ways to work the same material.
Every question in Genetics, Stem Cell Research and Cloning, on a schedule.
Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.
Or £46 a year, about £3.83 a month. Cancel anytime.