Across
- 2. The number of categories minus one.
- 6. A type of selection that favours individuals with extreme phenotypes and selects against those with phenotypes close to the mean.
- 7. A method of transformation in which a small electric current is used to transfer recombinant plasmids into bacterial cells or fragments of DNA into eukaryotic cells.
- 8. See ‘selective breeding’.
- 11. An enzyme that joins the sugar-phosphate backbone of two DNA segments.
- 15. When two or more genes are positioned on the same autosome. They are unlikely to be separated by crossing over during meiosis so are often inherited together.
- 17. A version of a gene.
- 18. A type of variation that cannot be categorised e.g. skin colour, height. It Produces A Continuous Range In Which A Characteristic Can Take Any Value. Multiple Genes influence continuous variation.
- 20. The gradual change in the allele frequencies within a population over time.OccursDueToNaturalSelection.
- 22. Describes a relationship between genes at different loci, where the allele of one gene affects the expression of a different gene.
- 24. A chromosome that is not an X or Y chromosome.
- 25. A condition in plants characterised by weak stems and small, pale leaves, due to insufficient exposure to light.
- 26. A technique used to determine the patterns in the non-coding DNA of an individual. It involves five main stages: DNA extraction; digestion; separation of DNA fragments; hybridisation; and observation.
- 27. A sequence of DNA that codes for an amino acid sequence.
- 28. A drastic reduction in population size leading to reduced genetic diversity within a population.
- 29. A therapeutic technique in which a faulty allele is replaced with a functional allele in order to treat or prevent disease.
- 30. A statistical test used to determine whether a pattern of inheritance is statistically significant.
- 33. A form of gene mutation in which one or more nucleotide bases are removed from a DNA sequence. This may lead to a frameshift mutation, changing every successive codon.
- 35. A type of selection that favours one extreme phenotype and selects against all other phenotypes.
- 36. The development of the computer tools and software required to organise and analyse unprocessed biological data.
Down
- 1. An organism that has had its genome altered.
- 3. The determination of a trait by the inheritance of two genes.
- 4. The use of computational techniques to analyse large amounts of biodata and build theoretical models of biological systems.
- 5. A type of variation that can be categorised e.g. blood group. A characteristic can only appear in discrete values. One or two genes influence discontinuous variation.
- 9. A change to at least one nucleotide base in DNA or the arrangement of bases. Gene mutations can occur spontaneously during DNA replication and may be beneficial, damaging, or neutral.
- 10. The complete genetic material of an organism.
- 12. A type of chromatography that separates nucleic acid fragments or proteins by size using electric current.
- 13. The modification of the genome of an organism by the insertion of a desired gene from another organism. This enables the formation of organisms with beneficial characteristics.
- 14. A type of genetic drift in which a few individuals of a species break off from the population and form a new colony. This results in smaller gene pools and an increased frequency of rare alleles.
- 16. Random variations in allele frequencies in small populations, due to mutations.
- 19. Describes an allele that is always expressed. Represented by a capital letter.
- 21. Programmed cell death. This is important for pruning surplus cells and tissues in development.
- 23. Determining the entire DNA nucleotide base sequence of an organism.
- 24. A form of speciation that occurs when two populations become geographically isolated due to a physical barrier.
- 31. When both alleles for a gene in a heterozygous organism equally contribute to the phenotype.
- 32. A short sequence of DNA that is used to identify a species. DNA barcodes are common to all species but vary between species.
- 34. A condition in which plant leaf cells produce insufficient chlorophyll, resulting in pale or yellow coloured leaves. This may be due to mineral deficiencies, lack of light, or viral infections.