Heredity Pop Quiz

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Across
  1. 4. The allele IA codes for blood type A, IB for blood type B, and Io for blood type O. Both IA and IB are dominant over Io, but IA and IB are __________.
  2. 7. __________ inheritance involves the inheritance of only one characteristic controlled by only one pair of contrasting alleles.
  3. 8. In the presence of a dominant allele, the __________ allele does not express itself.
  4. 9. __________ traits require only one allele to be present for the trait to be expressed.
  5. 10. A person is __________ if the two alleles for a particular characteristic are different.
  6. 11. Height is an example of __________variation in which there is a gradual transition from one extreme to another.
  7. 13. Different forms of a gene, occupying the same relative position on a chromosome.
Down
  1. 1. Down’s syndrome is a diseases caused by __________ mutations.
  2. 2. The genetic make-up of an organism.
  3. 3. __________ factors affect continuous variation, but not discontinuous variation.
  4. 5. The basic unit of inheritance.
  5. 6. The outward appearance or visible trait of an organism.
  6. 12. __________ selection refers to the process which results in organisms with traits best suited for the environment, surviving to reproduce and pass on their genes to the next generation.