unit 4 bio

    Cards (76)

    • What are the key similarities and differences between eukaryotic and prokaryotic DNA?
      Similarities:
      • Both made of DNA nucleotides
      • Both joined by phosphodiester bonds

      Differences:
      • Eukaryotic DNA is longer and linear
      • Prokaryotic DNA is circular
      • Eukaryotic DNA is associated with histones, prokaryotic DNA is not
    • What is the structure of eukaryotic DNA in the nucleus?
      It is tightly coiled into chromosomes
    • What is the function of the DNA in mitochondria and chloroplasts?
      To transcribe and translate enzymes needed for photosynthesis and respiration
    • What is a gene and what does it code for?
      • A gene is a sequence of DNA
      • It codes for the amino acid sequence of a polypeptide
      • It also codes for functional RNA, such as mRNA
    • What is the definition of locus in genetics?
      The exact position of a gene on a chromosome
    • What are the features of the genetic code?
      1. It is a degenerate code
      2. It is universal
      3. It is non-overlapping
    • Why is the genetic code considered degenerate?
      Because multiple triplets can code for the same amino acid
    • How many possible triplet combinations are there with three DNA bases?
      64 possible combinations
    • What is a codon?
      A codon is three bases on mRNA that codes for a specific amino acid
    • What is the role of introns and exons in DNA?
      Introns do not code for polypeptides, while exons do
    • What is a start codon?
      A start codon is three bases that initiate translation
    • What is a stop codon?
      A stop codon is three bases that signal the end of translation
    • What is the difference between a genome and a proteome?
      • Genome: Complete set of genes in a cell
      • Proteome: Full range of proteins a cell can produce
    • How does the genome differ between species?
      Different species have different numbers of DNA base pairs
    • How many DNA base pairs do humans have in their genome?
      Three billion DNA base pairs
    • What is the role of mRNA in protein synthesis?
      mRNA carries the genetic code from DNA to the ribosome
    • What is the structure of tRNA?
      tRNA has a cloverleaf shape and an amino acid binding site
    • What is the function of the anticodon on tRNA?
      The anticodon is complementary to a codon on mRNA
    • What are the two main stages of protein synthesis?
      1. Transcription: DNA is copied into mRNA
      2. Translation: mRNA is translated into a polypeptide chain
    • What happens during transcription?
      A complementary mRNA copy of a gene is created in the nucleus
    • What are the key steps in transcription?
      1. DNA helix unwinds
      2. One strand acts as a template
      3. RNA nucleotides align opposite DNA bases
      4. RNA polymerase joins RNA nucleotides
      5. mRNA is modified and leaves the nucleus
    • What is splicing in eukaryotes?
      Splicing is the removal of introns from pre-mRNA
    • What is the role of the ribosome in translation?
      The ribosome holds tRNA molecules in place to join amino acids
    • What is the significance of peptide bonds in translation?
      Peptide bonds join amino acids together
    • What are the modifications that occur to a polypeptide chain after translation?
      • Folding in the Golgi body
      • Formation of secondary, tertiary, or quaternary structures
    • What is a gene mutation?
      A gene mutation is a change in the base sequence of DNA
    • When do gene mutations typically occur?
      During DNA replication in interphase
    • What are mutagenic agents?
      Agents that can increase the likelihood of mutations
    • What is non-disjunction?
      Non-disjunction is the failure of chromosomes to separate properly during meiosis
    • What are the two forms of chromosome mutations?
      1. Polyploidy: Change in the whole set of chromosomes
      2. Aneuploidy: Change in the number of individual chromosomes
    • What is polyploidy?
      Polyploidy is having multiple copies of every chromosome
    • What is aneuploidy?
      Aneuploidy is having an abnormal number of individual chromosomes
    • What is the result of non-disjunction during meiosis?
      It can lead to gametes with an abnormal number of chromosomes
    • How does Down syndrome occur?
      Down syndrome occurs due to non-disjunction of chromosome 21
    • What is the role of histones in eukaryotic DNA organization?
      Histones help to tightly coil DNA into chromosomes
    • How does transcription differ in prokaryotes compared to eukaryotes?
      Prokaryotes do not have introns, so splicing does not occur
    • What is the significance of hydrogen bonds in tRNA structure?
      Hydrogen bonds help maintain the cloverleaf shape of tRNA
    • What is the role of spliceosomes in RNA processing?
      Spliceosomes remove introns from pre-mRNA
    • What are the differences between mRNA and tRNA?
      mRNA carries the genetic code, while tRNA brings amino acids
    • Why is ATP important in translation?
      ATP provides the energy needed to form peptide bonds
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