Biology a level

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Across
  1. 2. Increased addition of methyl groups to DNA causing the DNA to coil up
  2. 6. A group of 3 nucleotides which are complementary to another group of 3 nucleotides; often found on tRNA
  3. 11. The process by which stem cells divide to make more stem cells, requiring cell cycle control and maintenance of multipotency and pluripotency, depending on the stem cell.
  4. 12. An enzyme which cuts RNA at specific points used in genetic engineering
  5. 13. mRNA which contains introns
  6. 14. Bonds which occur between the lone pair of electrons of an oxygen atom and the hydrogen atom of another molecule
  7. 15. Heritable changes in gene function, without changes to the base sequence of DNA.
  8. 17. A technique used for the amplification of DNA in vitro (outside of normal cellular environment)
  9. 18. Heating of DNA to very high temperatures to break hydrogen bonds and then cooling to much lower temperatures to allow for DNA replication
  10. 21. A single strand of DNA which is transcribed to create and complimentary copy used for DNA replication
  11. 22. Sequence of nucleotides in DNA or RNA where the sequence of one strand is the same as the complementary sequence of the other strand (read from the same direction e.g. 3’ to 5’)
  12. 25. Cells found in mature mammals that can divide to form a limited number of different cell types
  13. 26. A region of DNA which comes upstream of a transcriptional start site where specific transcription factors can bind to activate RNA polymerase to transcribe the gene.
  14. 27. Single stranded sequence of DNA or RNA used to search for its complementary sequence in a sample genome.
  15. 28. A protein which a specific tertiary structure, complementary to its substrate/ binding protein
  16. 29. Multiple triplets can form the same amino acid
Down
  1. 1. A protein complex which binds to specific regions of DNA promoting the replication of DNA by activating DNA polymerase
  2. 3. Substances which kill or inhibit the growth of bacteria by damaging the cell wall (by preventing bonds forming between the murein molecule) or preventing protein synthesis.
  3. 4. An enzyme which binds together sticky ends of plasmids, used in genetic engineering
  4. 5. A group of 3 nucleotides which are translated in a ribosome to code for one amino acid
  5. 7. The sequence of nucleotides which contains the partner nucleotides to another strand of DNA
  6. 8. The base which binds to adenine in RNA
  7. 9. A technique used to separate DNA fragments based on their size and charge
  8. 10. A gene that is transferred with the desired gene to enable scientists to identify which cells have been successfully altered and now contain recombinant DNA
  9. 16. The process by which a DNA sequence is copied into an mRNA sequence from a DNA template strand by the enzyme RNA polymerase.
  10. 17. Small, circular rings of double-stranded DNA found in bacteria.
  11. 19. Cells which divide to produce any type of body cell; occur only for a limited time in early mammalian embryos.
  12. 20. The enzyme which bonds together nucleotides with the sugar phosphate backbone
  13. 23. Primers are sequences of single-stranded DNA that have base sequences complementary to the 3’ end of the DNA or RNA being copied. They define the region that needs to be amplified by identifying to the DNA polymerase where to begin building new strands.
  14. 24. Less specialised cells develop to possess distinct form and function.