Biology Revision Y9

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Across
  1. 5. Variation The differences among individuals due to different environments
  2. 7. All the possible versions of genes
  3. 9. When an individuals has two of the same allele either dominant or recessive
  4. 11. When a species completely disappears
  5. 12. Variation When traits have clear separate categories
  6. 14. A strand of DNA. They are found in the nucleus. 46 chromosomes(23 from each parent)
  7. 17. The appearance of the organisms ( physical appearance)
  8. 18. All about protecting nature and species from extinction
  9. 19. Variation Differences between individuals within a species. It can be continuous or discontinuous.
  10. 20. A doubled stranded helix shaped molecule made of things called nucleotides
  11. 21. Refers to the trait that is masked when a dominant allele is present
Down
  1. 1. It is the characteristic
  2. 2. Selection A process by which a species changes over time in response to changes in the environment
  3. 3. A length of DNA that codes for a trait
  4. 4. Having two different alleles for a fruit
  5. 6. The adjustment of organisms to their environment in order to improve their chances at survival in that environment
  6. 8. Tells you the alleles that lead to this appearance
  7. 10. Variation When traits fall into range with no distant categories
  8. 13. A building block of DNA AND RNA(molecules)
  9. 15. A group of living organisms that can interbreed to produce fertile offspring
  10. 16. The cell's control centre, housing DNA