1. Chapter 11 – Genetics Vocabulary Overview
Mr. Davis
Biology

2. Genetic Vocabulary
Allele: one of two or more different versions of the same gene.
Dominant Allele: allele that masks the presence of another allele for the same gene when they occur together in a heterozygote.
Genetics: the science of heredity..
Genotype: alleles an individual inherits at a particular genetic locus
Heterozygote: organism that inherits two different alleles for a given gene.
Homozygote: organism that inherits two alleles of the same type for a given gene.
Hybrid: offspring that results from a cross between two different types of parents .
Biology

3. Genetic Vocabulary
Law of Independent Assortment: Mendel’s second law stating that factors controlling different characteristics are inherited independently of each other.
Law of Segregation: Mendel’s first law stating that the two factors controlling a characteristics separate and go to different gametes.
Locus: position of a gene on a chromosome.
Phenotype: characteristics of an organism that depend on how the organism’s genotype is expressed.
Pollen: tiny grains that bear the male gametes of seed plants and transfer sperm to female reproductive structures.
Pollination: fertilization in plants in which pollen is transferred to female gametes in an ovary.
Recessive Allele: allele that is masked by the presence of another allele for the same gene when they occur together in a heterozygote.
Biology

4. Genetic Vocabulary
Codominance: relationship between two alleles for the same gene in which both alleles are expressed equally in the phenotype of the heterozygote.
Incomplete Dominance: relationship between the alleles for a gene in which one allele is only partly dominant to the other allele so an intermediate phenotype results.
Polygenic Characteristic: characteristic, or trait, controlled by more than one gene, each of which may have two or more alleles.
Probability: the likelihood, or chance, than a certain event will occur.
Punnett Square: chart for determining the expected percentages of different genotypes in the off spring of two parents.
Biology

5. Biology

6. Meiosis

7. Mr. Davis
Genetic Mutations
Biology

8. Mutations
Mutations are mistakes that occur in copying their own DNA. Mutations are changes in the genetic material.
Gene mutations result from changes in a single gene. Genetic mutations affect the amino acid sequences of the proteins for which they code.
Biology

9. Biology

10. Mutation
A mutation is a permanent change in the DNA sequence of a gene. Sometimes mutations can be useful but mostly they are harmful as changes in DNA can change the way a cell behaves. As genes are a set of hereditary materials that contain instructions necessary for a cell to work so if some of these instructions go wrong the cell may not know how to function.
Biology

11. Biology

12. Kinds of Mutations 2 Gene Mutations Point Mutation Frameshift Mutation
4 Chromosomal Mutations
Deletion
Duplication
Inversion
Translocation
Biology

13. Point Mutation
Gene mutations involving changes in one or a few nucleotides because they occur at a single point in the DNA sequence.
Biology

14. Sickle Cell Anemia
Sickle cell anemia is the result of a point mutation in codon 6 of the -globin gene resulting in the substitution of amino acid Glutamic acid by Valine.
Biology

15. Sickle Cell Anemia
Under conditions of low oxygen atmospheres containing a low oxygen level, the following changes occur:
(1) The hemoglobin agglutinates to form insoluble rod-shaped polymers;
(2)Red blood cells become distorted and sickle-shaped
(3) The sickle-shaped cells rupture easily causing hemolytic anemia;
(4)The sickle shaped cells tend to block capillaries interfering with the blood flow to various organs.
Biology

16. Sickle Cell Anemia
Biology

17. Frameshift Mutation
A frameshift mutation is a genetic mutation caused by a deletion or insertion in a DNA sequence that shifts the way the sequence is read. A DNA sequence is a chain of many smaller molecules called nucleotides.
Biology

18. Frameshift Mutation
Biology

19. Frameshift Mutations
Frameshift mutations can alter a protein so much that it is unable to perform its normal functions.
Biology

20. Biology

21. Chromosomal Mutations
Chromosomal Mutations involve changes in the number or structure of chromosomes.
Chromosomal mutations change the number of copies of genes.
Biology

22. 4 Types of Chromosomal Mutations
Deletions
Duplication
Inversions
Translocations
Biology

23. 1. Chromosomal Mutation - Deletion
Original Chromosome: ABCDEF   Deletion: ACDEF: deletions involve the loss of all or part of a chromosome.
Biology

24. 2. Chromosomal Mutation - Duplication
Duplication: ABBCDEF: duplications produce extra copies of parts of a chromosome.
Biology

25. Biology

26. 3. Chromosomal Mutation - Inversion
Original Chromosome: ABCDEF   Inversion: AEDCBF: inversions reverse the direction of parts of a chromosome.
Biology

27. Inversion
Biology

28. 4. Chromosomal Mutation - Translation
Translocation: ABCJKL: translations occur when part of one chromosome breaks off GHIDEF and attaches to another
Biology

29. 4 Types of Chromosomal Mutations
Biology

30. Genetic Mutagens
Mutagens are substances or conditions that cause mutations. Mutations are changes in the genetic code.
Biology

31. Mutagen Examples Radiation (UV-light) Extreme High Temp. Chemicals
Tar & Nicotine
Biology

32. Examples of Mutagens
Biology

33. Genetic Mutagens
Biology

34. Chemical Mutagens
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35. Biology