NUCLEUS
transcription
transcription
RIBOSOME
translation
translation
š How this works
Your retake is basically this unit.
Do the lessons in order, then the final retake quiz. Every wrong answer tells you why and what to review.
š©āš«
Coach: Your highest-value topics are RNA types, transcription vs translation, codons/anticodons, mutation types, and replication enzymes.
Most missed
Q1, Q2, Q4, Q6, Q7, Q8, Q23, Q24.
Fast rule
DNA uses T. RNA uses U. Codon charts use mRNA codons.
Mutation rule
Same length = substitution. Longer = insertion. Shorter = deletion.
| Test area | Need to know |
|---|---|
| Central dogma | DNA ā RNA ā protein |
| RNA types | mRNA message, rRNA ribosome, tRNA transfer amino acids |
| Codons | 3 bases; AUG start; UAA/UAG/UGA stop |
| Mutations | silent, missense, nonsense, insertion, deletion, frameshift |
š§¬ Lesson 1
DNA Structure and DNA vs RNA
š©āš«
Coach: DNA is made of nucleotides. Each nucleotide has a phosphate, sugar, and base. The rails/backbone are sugar-phosphate. The rungs are nitrogen bases. DNA is a double helix.
DNA nucleotide parts
phosphate group + 5-carbon sugar + nitrogenous base
DNA bases: A, T, C, G. RNA bases: A, U, C, G.
Base pairing trainer
Chargaffās rule
[A] = [T] and [C] = [G].
If A = 30%, T = 30%.
Discovery
Rosalind Franklin used X-ray diffraction. Watson and Crick built the double helix model. Hershey-Chase showed DNA transmits genetic information.
From Lesson 1 slides: nucleotides, double helix, base-pairing, DNA/RNA comparison, Griffith; plus Lesson 2 discovery slides.
ā»ļø Lesson 2
DNA Replication
š©āš«
Coach: Replication copies DNA before cell division. Helicase unzips, polymerase builds, ligase glues. Semiconservative means each copy has one original strand and one new strand.
Enzyme picker
DNA helicase
Semiconservative visual
Original: OLD + OLD
Copy 1: OLD + NEW
Copy 2: OLD + NEW
Copy 1: OLD + NEW
Copy 2: OLD + NEW
Not conservative. Not dispersive.
š§« Lesson 3
RNA, Transcription, Translation
š©āš«
Coach: Transcription copies DNA into mRNA in the nucleus. Translation reads mRNA at the ribosome to build protein. Exons are expressed; introns are removed.
RNA type trainer
Transcribe DNA into mRNA
Introns vs Exons
Introns = intervening, removed. Exons = expressed, used for protein synthesis.
Central dogma
DNA ā RNA ā protein
š Lesson 4
Codons, Anticodons, Amino Acids
š©āš«
Coach: A codon is 3 mRNA bases. Each codon specifies an amino acid. Codon charts use mRNA codons, not tRNA anticodons.
Drag-and-drop codon builder
mRNA translator
Start/Stop
AUG = start + methionine
UAA = stop UAG = stop UGA = stop
UAA = stop UAG = stop UGA = stop
Anticodon finder
ā ļø Lesson 5
Mutations
š©āš«
Coach: Mutation questions are usually solved by checking what changed: one base swapped, base added, base removed, early stop codon, or same amino acid.
Substitution / Point
One base changed to a different base. Same length.
TAC GCA
TAC GTA
TAC GTA
Insertion
One base added. Longer. Often frameshift.
TAC GCA
TAC GGCA
TAC GGCA
Deletion
One base removed. Shorter. Often frameshift.
TAC GCA
TAC CA
TAC CA
Detect the mutation
Mutation effects
| Type | Meaning |
|---|---|
| Silent | same amino acid |
| Missense | different amino acid |
| Nonsense | early stop codon |
| Frameshift | reading frame shifts |
š§Ŗ Biotech
Biotechnology Tools
š©āš«
Coach: This is small but shows up on the test: gel electrophoresis separates DNA fragments, CRISPR edits genes, restriction enzymes cut DNA, and genetic engineering deliberately changes DNA.
Tool chooser
Separate DNA fragments by size/charge
DNA scissors
Restriction enzymes cut DNA at specific sequences.
GAATTC
CTTAAG
cut site ā
CTTAAG
cut site ā
š Adaptive Review
Weak Spots
Every wrong quiz answer gets saved here with what to review.
No weak spots yet. Take quizzes first.
š Final Retake
25-question Retake Simulator
This follows the style of the test screenshots. Wrong answers explain why.