SCIENCE UNIT TEST

• Who discovered the structure of DNA?

  James Watson and Francis Crick
• Who took the first photo of DNA?

  Rosalind Franklin
• Who discovered that DNA was genetic material?

  Oswald Avery
• What does DNA stand for?

  Deoxyribonucleic Acid
• How many strands are there in DNA?

  2
• What is the shape of DNA?

  Double Helix
• What are the three parts of a DNA nucleotide?

  Sugar, phosphate, nitrogenous base
• What are the four nitrogen bases and how do they pair?

  Adenine, Thymine, Guanine, Cytosine. They pair as A-T and G-C.
• What does helicase do?

  Unzips DNA strands

  
• What does DNA polymerase do?

  Forms new copies of DNA in the form of nucleic acid molecules

  
• What is the difference between the leading and lagging strands?

  The leading strand is synthesized in the same direction as the movement of the replication fork, and the lagging strand is synthesized in the opposite direction

  
• What are Okazaki fragments?

  Short DNA fragments synthesized on the lagging strand during DNA replication.
• What are 3 main differences between DNA and RNA?

  1. Sugar in RNA is ribose, while in DNA it is deoxyribose. 2. RNA is usually single-stranded, while DNA is double-stranded. 3. RNA contains uracil as a base instead of thymine found in DNA.
• What does mRNA do?

  mRNA is the messenger. It carries the genetic information from DNA to the ribosomes for protein synthesis.
• What does tRNA (ribosomes) do?

  tRNA is the transfer. It carry amino acids to the ribosome during protein synthesis.
• What are promoter and terminator sequences?

  DNA sequences that signal the start of gene transcription (promoter) and the end of gene transcription (terminator).
• Where does transcription occur within a eukaryotic cell?

  Nucleus
• How are the processes of transcription and DNA replication similar?

  Both DNA Replication and Transcription involve creating a new copy of the DNA in a cell
• What is RNA splicing?

  A process that removes the non-coding sequences of genes (introns) from pre-mRNA and joins the protein-coding sequences (exons) together in order to enable translation of mRNA into a protein.
• Which is included in the final mRNA molecule, exons or introns?

  Exons
• What is a codon?

  A sequence of three nucleotides in DNA or RNA that codes for a specific amino acid during protein synthesis.
• What is a mutation and how do they occur?

  A mutation is an alteration in the nucleic acid sequence. They occur from errors in DNA replication.
• What is translation in DNA?

  The process of converting the information in mRNA into a sequence of amino acids to form a protein.