Unit 6 Vocabulary1. genetics- the scientific study of

heredity2. Gregor Mendel- monk and scientist who discovered the basic principles of genetics through pea experiments; the father of genetics

Unit 6 Vocabulary3. principle of dominance- some alleles are

dominant and others are recessive

4. principle of segregation- during gamete formation, alleles separate (segregate) away from each other so that each gamete only receives a single copy of each gene

5. principle of independent assortment- genes for different traits can separate without effect on each other during the formation of gametes

Unit 6 Vocabulary6. chromosome- a single strand of tightly coiled DNA

7. gene- the factors that are passed from parent to offspring

Unit 6 Vocabulary8. trait- a specific characteristic, such as height, of an individual

9. allele- one of a number of different forms of a gene

Unit 6 Vocabulary10. dominant- an allele that is expressed and masks recessive alleles

11. recessive- an allele that is only expressed when no dominant alleles are present

Unit 6 Vocabulary12. genotype- genetic makeup

13. phenotype- physical traits

Unit 6 Vocabulary14. polygenic trait- a trait controlled by two or more genes; Ex: eye color

Unit 6 Vocabulary

15. self-pollination- when sperm fertilize eggs within the same flower

16. cross-pollination- when sperm from one flower fertilize the eggs of another

Unit 6 Vocabulary

17. P- parental generation

18. F1- the offspring from the P generation; first filial generation

19. F2- the offspring from the F1 generation; second filial generation

Example:

Unit 6 Vocabulary20. true-breeding/pure breeding- offspring produced always have the same phenotype as the parents

Purebred: Not Purebred:

Unit 6 Vocabulary22. sex chromosomes- chromosomes involved in sex determination; X or Y

Autosomes: Sex Chromosomes:

21. autosome- a body chromosome; any chromosome not involved in sex determination

Unit 6 Vocabulary23. homozygous- organisms that have two identical alleles for a particular gene;

Ex- TT or tt

23a. homozygous dominant- when the two identical alleles for a particular gene are both dominant; Ex- TT

23b. homozygous recessive- when the two identical alleles for a particular gene are both recessive; Ex- tt

24. Heterozygous- when the two alleles for a particular gene are different; Ex- Tt

PP

Pppp

Unit 6 Vocabulary25. fertilization- the joining of

male and female gametes26. gamete- a haploid reproductive cell; egg or sperm

Unit 6 Vocabulary

27. XX- female genotype

28. XY- male genotype

Unit 6 Vocabulary29. Punnett Square- a simple diagram that is used to predict the genotype and

phenotype combinations in a genetic cross

30. monohybrid cross- the cross between parents with different alleles for a single gene

Unit 6 Vocabulary31. co-dominance- the

phenotypes produced by both alleles are clearly expressed; no ‘blending’

32. incomplete dominance- when one allele is not completely dominant over another; phenotypes appear to ‘blend’

Unit 6 Vocabulary33. probability- the likelihood that a

particular event will occur; Ex- the probability of tails when flipping a coin

34. hybrid- the offspring of crosses between parents with different traits

Unit 6 Vocabulary

35. dihybrid cross- a cross between individuals with different alleles for two genes

Unit 6 Vocabulary36. multiple alleles- a gene with more than two alleles

Unit 6 Vocabulary37. agglutination- the act of clumping together38. type A blood genotypes- IAIA, IAi39. type B blood genotypes- IBIB, Ibi40. type AB blood genotype- IAIB

41. type O blood genotype- ii

Unit 6 Vocabulary42. pedigree- a diagram showing the lineage of a family for a particular

characteristic

43. carrier- an organism that has a recessive gene that is defective

Unit 6 Vocabulary44. linked genes- genes that are located close together on the same chromosome and often inherited together

45. sex-linked trait- trait whose genes are located on a sex chromosome

46. colorblindness- a sex-linked inherited condition where there is an inability to distinguish some colors

Unit 6 Vocabulary47. mutation- a change in gene

Example: Mutation due to UV Light