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Mutations

  1. What is a mutation?
    A change in the structure or amount of an organism's genetic material
  2. What do you call an organism whose phenotype has been changed by the mutation in the genotype?
    A mutant
  3. What are the three groups mutations can be put into?
    • Change in chromosome number
    • Change in chromosome structure
    • Change in gene structure
  4. What kind of mutations can result in a change in chromosome number?
    • Non-disjunction of chromosome 21 - Down's syndrome
    • Non-disjunction of sex chromosomes - Turner's syndrome
    • Complete non-disjunction - Polyploidy
  5. Name and describe the type of mutations that can result in a change in chromosome structure?
    • Deletion - a chromosome breaks but when it rejoins part of it is lost (genes are deleted)
    • Duplication - a chromosome breaks and when it rejoins genes from its homologous chromosome are added in
    • Translocation - when genes from one chromosome bread off and join on to another non-homologous chromosome
    • Inversion - when a chromosome breaks and some genes rotate 180° before it rejoins
  6. Which of these mutations are lethal?
    Deletion
  7. Name and describe the types of mutations that can result in a change in gene structure?
    • Deletion - when one nucleotide is removed
    • Insertion - when one nucleotide is added
    • Inversion - when two or more nucleotides are swapped over
    • Substitution - when one nucleotide is replaced by another
  8. Which of these are point mutations?
    Subsititution and inversion
  9. Which of these are frameshift mutations?
    Insertion and deletion
  10. Mutations occur randomly and ____?
    rarely
  11. The majority of mutant alleles are...?
    recessive
  12. When do some mutant alleles show up?
    If they are dominant or sex linked
  13. Anything which causes a mutation is called a...?
    mutagen
  14. The rate of mutations can be increased by mutagenic agents such as...?
    • Chemicals - eg mustard gas
    • Radiation - eg gamma, x-ray and ultraviolet
  15. Mutations are a source of ...?
    variation
Author
Anonymous
ID
129958
Card Set
Mutations
Description
Higher Biology - Unit Two - Mutations
Updated

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