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Flashcards · Biology · Inheritance

Genetic Variants and Phenotype (Higher tier)

16 cards

  1. What is coding DNA?

    DNA that codes for proteins, in genes.

  2. What is non-coding DNA?

    DNA that does not code for a protein.

  3. How can a variant in coding DNA affect a protein?

    It can change the amino acid sequence, so the shape and the activity change.

  4. How can a variant affect an enzyme?

    It can change the shape of the active site, so the substrate no longer fits.

  5. How can a variant in non-coding DNA affect the phenotype?

    It can change how the gene is expressed.

  6. What can a non-coding variant stop?

    Transcription of the mRNA.

  7. What is gene expression?

    How a gene is used to make its protein.

  8. What effect would stopping transcription have?

    Less, or none, of the protein is made.

  9. Do most variants affect the phenotype?

    No, most have no effect.

  10. What does a frameshift do?

    Changes all of the triplets after the change.

  11. Why can the same amino acid be made after a base change?

    More than one triplet codes for the same amino acid.

  12. Are the terms promoter and transcription factor required?

    No.

  13. What is sickle cell disease an example of?

    A variant in coding DNA that changes a protein.

  14. What is lactase persistence an example of?

    A variant in non-coding DNA that changes the amount of a protein.

  15. Why does a changed active site stop an enzyme working?

    The substrate does not fit, so no complex forms.

  16. Common mistake about non-coding DNA?

    Saying that it has no function. It can control how genes are expressed.