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• What are the similarities between DNA in eukaryotic and prokaryotic cells?

  Identical nucleotide structure
• The nucleotide structure in DNA includes deoxyribose attached to a phosphate group and a base
• Adjacent nucleotides in DNA are joined by phosphodiester bonds, while complementary bases are joined by hydrogen bonds.
• Where is DNA with a similar structure to prokaryotic DNA found in eukaryotic cells?

  Mitochondria and chloroplasts
• Prokaryotic-like DNA in eukaryotic organelles is short, circular, and not associated with proteins
• What is the shape of eukaryotic DNA compared to prokaryotic DNA?

  Linear versus circular
• Eukaryotic DNA is associated with histone proteins, whereas prokaryotic DNA is not.
• Eukaryotic DNA contains non-coding regions called introns
• What is a chromosome in eukaryotic cells composed of?

  DNA and histone proteins
• What does a gene code for in eukaryotic cells?

  Polypeptide or functional RNA
• Match the term with its definition:

  Gene ↔️ Sequence of DNA coding for a product

  Chromosome ↔️ Long, linear DNA with histones

  Locus ↔️ Fixed position of a gene on DNA
• The genetic code is a triplet code where a sequence of three DNA bases, called a triplet, codes for a specific amino acid
• The genetic code is universal, meaning the same base triplets code for the same amino acids in all organisms.
• What does it mean for the genetic code to be non-overlapping?

  Each base is part of one triplet
• The genetic code is degenerate because an amino acid can be coded for by more than one base triplet
• What are non-coding base sequences in DNA called?

  Introns
• In eukaryotes, much of the nuclear DNA does not code for polypeptides.
• An exon is a base sequence of a gene coding for amino acid sequences in a polypeptide
• What is an intron in eukaryotic DNA?

  Non-coding base sequence
• What is the complete set of genes in a cell called?

  Genome
• The proteome is the full range of proteins that a cell can produce
• Protein synthesis occurs in two stages: transcription and translation.
• Arrange the stages of protein synthesis in the correct order:

  1️⃣ Transcription in the nucleus

  2️⃣ mRNA production from DNA

  3️⃣ Translation at ribosomes

  4️⃣ Polypeptide formation
• What are the similarities between tRNA and mRNA?

  Single polynucleotide strand
• tRNA is folded into a clover leaf shape, while mRNA is linear
• Which molecule has an anticodon, tRNA or mRNA?

  tRNA
• In RNA, uracil is used in place of thymine
• In prokaryotic cells, mRNA is produced directly without splicing, whereas pre-mRNA is produced in eukaryotic cells.
• What is the start codon on mRNA called?

  AUG
• Describe the steps of translation leading to polypeptide formation:

  1️⃣ mRNA attaches to a ribosome

  2️⃣ tRNA anticodon binds to mRNA codon

  3️⃣ Amino acids join by peptide bonds

  4️⃣ tRNA is released

  5️⃣ Ribosome moves along mRNA to a stop codon
• ATP hydrolysis provides energy for peptide bond formation during translation.
• The ribosome moves along mRNA until it reaches a stop codon
• Match the molecule with its role in translation:

  ATP ↔️ Energy for peptide bond formation

  tRNA ↔️ Transports specific amino acids

  Ribosome ↔️ Catalyses peptide bond formation
• tRNA anticodons are complementary to mRNA codons.
• In RNA, uracil replaces thymine
• What is a gene mutation?

  Change in DNA base sequence
• A mutagenic agent is a factor that increases the rate of gene mutation
• Describe how a mutation can lead to the production of a non-functional protein:

  1️⃣ Changes in DNA base triplets

  2️⃣ Changes in mRNA codons

  3️⃣ Changes in amino acid sequence

  4️⃣ Changes in protein tertiary structure

  5️⃣ Active site of enzyme changes shape
• What happens in a substitution mutation?

  One base is replaced
• A deletion mutation causes a frameshift, changing the sequence of DNA triplets from the point of mutation.