HA

Chapter 12 - Vocabulary

  1.  Genetics- scientific study of heredity

  2.  Fertilization- process in sexual reproduction in which male and female reproductive cells join to form a new cell

  3.  Trait- scientific characteristic of an individual

  4.  Hybrid- offspring of crosses between parents with different traits

  5.  Gene- sequence of DNA that codes  for a protein and thus determines a trait; factor that is passed from parents to offspring

  6.  Allele- one number of different forms of a gene

  7.  Principle of dominance Mendel's second conclusion, which states that some allele are dominant and others are recessive

  8.  Segregation- separation of alleles during gamete formation

  9.  Gamete- sex cell

  10. Probability-likelihood that a particular event will occur

  11. Homozygous- having two identical alleles for a particular gene

  12. Heterozygous- having two different alleles for a particular gene

  13. Phenotype- physical characteristics of an organism

  14. Genotype- genetic makeup of an organism

  15. Punnett square- diagram that can be used to predict the genotype and phenotype combinations of a genetic cross

  16. Independent assortment- one of Mendel’s principles that states that genes for different traits can segregate independently during the formation of gametes

  17. Incomplete dominance- situation in which one allele is not completely dominant over another allele

  18. Codominance- situation in which the phenotypes produced by both alleles are completely expressed

  19. Multiple alleles- a gene that has more than two alleles

  20. Polygenic trait- trait controlled by two or more genes

  21. Homologous- term used to refer to chromosomes in which one set comes from the male parent and one set comes from the female parent

  22. Diploid- term used to refer to a cell that contains two sets of homologous chromosomes

  23. Haploid- term used to refer to a cell that contains only a single set of genes

  24. Meiosis- process in which the number of chromosomes per cell is cut in half through the separation of homologous chromosomes in a diploid cell

  25. Tetrad- structure containing four chromatids that forms during meiosis

  26. Crossing-over- process in which homologous chromosomes exchange portions of their chromatids during meiosis