Higher Biology

• A cell genotype is determined by


  The sequence of DNA in its genes
• What proccesss does gene expression involve

  Transcription and translation
• Gene expression is controlled by regulating


  Both transcription and translation
• Only fraction of the genes are expressed ?

  True, yes
• Each RNA molecule is made up of a

  Base, phosphate and ribose sugar
• What are all nucleic acids

  DNA and all types of RNA
• What are the bases in RNA

  Adenine, Cytosine, Uracil, Guanine
• What is the name haven to the triplets of bases in a mRNA

  Codon
• Where does the transcription of genetic sequences of DNA take place

  Nucleus
• Where does the translation of genetic sequences take place

  Ribosome
• A codon codes for a single amino acid


  True
• Which section of dna is removed of the primary transcript after transcription

  Introns
• What is the initial result of the mRNA complementary copy called

  Primary transcription
• The sequence of triplets on a strand of DNA is shown below.

  ATTACACCGTACCAATAG.

  During translation of mRNA made from the above sequence, how many of the tRNA anticodons will have at least one uracil base? *

  3
• Which of the following is a possible anticodon found on a tRNA molecule? *

  GGG

  ATC

  TRNA

  GTU

  GGG
• Phenotype is..

  Determined by the by the proteins produced by the result of gene expression AND ENVIRONMENTAL FACTORS
• When are the hydrogen binds formed


  They form as the primer c9mes into position and holds it in place for the polymerase to extend.
• Why can you only extend continuously the leading strand

  DNA polymerase can only add nucleotides to the 3' end of a growing strand, Eventhough though it technically starts a 5', just imagine a very short strand after the pr8mer is Initislly added
• Is ATP necessary for DNA replication .


  Yes
• Describe ways in which a polypeptide could be modified

  Cut and combine polypeptide chains or add phosphate
• State why the antiparallel nature of DNA molecules results in one of the strands being synthesied in short fragments

  Polymerase only adds to 3' end
• Name and describe the process which results in different mRNA molecules being expressed

  Name: Alternative RNA splicing

  Description : different combinations of exons are spliced together in the mature transcript.
• Read what carefully


  Difference between DNA and RNA etc
• Temp of stage 2 of pcr

  50 - 65 degrees Celsius
• Temp of stage 3 of pcr

  70 - 80 degrees Celsius
• Why in mutated samples of rRNA was there a decrease in protein synthesis


  Change in sequence may change the function and translation can no longer occur
• Name the bind that holds together the polypeptide chain

  Hydrogen
• One role of non-coding genome in the DNA

  Regulates transcription
• In eukaryotic cells, alternative RNA splicing occurs. Explain how this results in different proteins brunt expressed from a single gene

  There are different combinations of exons in the mature transcript
• tRNA is

  The protein coding genes in the human genome
• Why are two primers used in pcr

  1 for each strand
• Are chromosomes associated with proteins in prokaryotes

  No
• Explain why Ribsomes would contain radioactive uracil

  Ribosomes contains rRNA, which will contain Uracil
• Never do what?

  Put just the base letter and not full name
• What's the most forgettable part of DNA replication

  The DNA first unwinds
• Watch out for ..


  Difference between pro and eukaryote, always use rythme method
• Where does DNA replication occur

  nucleus
• tRNA ...


  Folds due to complementary base paring
• Role of tRNA

  to act as transporters bringing amino acids to the site of protein synthesis
• What is the name of the mRNA formed after the initial complementary copying

  Primary mRNA