1 / 87

Genetic Mutations: Types, Effects, and Causes

This chapter explores the various types of genetic mutations, their effects on organisms, and the causes behind these mutations. It also discusses the repair mechanisms in DNA and the use of pedigrees to study inheritance patterns.

jbanks
Download Presentation

Genetic Mutations: Types, Effects, and Causes

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 12 Advanced Genetics

  2. 11.3 Section Summary 6.3 – pages 296 - 301 Mutations • Mutation: a change in __. • May involve : • an entire __ • a specific __ • may take place in __ cell • When a mutation takes place the DNA is changed which affects the production of __. This may affect metabolism, development, or result in a new phenotype.

  3. 11.3 Section Summary 6.3 – pages 296 - 301 Mutations in reproductive cells • Germ cell mutation - occurs in the __ cells. • This does not affect that organism but may be passed on to the __. • If this cell takes part in __, the altered gene would become part of the genetic makeup of the offspring.

  4. 11.3 Section Summary 6.3 – pages 296 - 301 Mutations in reproductive cells result in: • A __ mutation - the embryo does not survive. • A __ that does not work correctly. • In some rare cases it may have a __ effect.

  5. 11.3 Section Summary 6.3 – pages 296 - 301 Mutations in body cells • __ mutations - mutations in body cells • Ex) • This mutation would __ be passed on to offspring.

  6. 11.3 Section Summary 6.3 – pages 296 - 301 Mutations in body cells result in: • Impairing the __ of the cell. • When that cell divides, the new cells also will have the same mutation. • Affecting genes that control __. • Cells may grow and divide rapidly, producing __

  7. 11.3 Section Summary 6.3 – pages 296 - 301 Types of Mutations • A) __: a change in a single base pair in DNA. • A single nitrogen base is __ by another • This may have __ noticeable affect or it can change the entire structure of a __ because a change in a single amino acid can affect the shape of the protein.

  8. 11.3 Section Summary 6.3 – pages 296 - 301 The effects of point mutations mRNA Normal Stop Protein ReplaceGwithA mRNA Point mutation Stop Protein

  9. 11.3 Section Summary 6.3 – pages 296 - 301 • B) __: mutation in which a single base is added or deleted from DNA. • Results in every __ after either the added or deleted base to be different. • This mutation would cause nearly every __ in the protein after the __ to be changed.

  10. 11.3 Section Summary 6.3 – pages 296 - 301 Frameshift mutations Deletion of U Frameshift mutation mRNA Protein

  11. 11.3 Section Summary 6.3 – pages 296 - 301 • C) __: Structural changes in chromosomes. • Occur during __ • can be either changes in the __ of a chromosome or a __ of an entire chromosome. • Are more __ types of mutations. • __ are passed on to the next generation because the zygote usually dies. • In cases where the zygote lives and develops, the mature organism is often __.

  12. 11.3 Section Summary 6.3 – pages 296 - 301 Types of Chromosomal Alterations • 1) Deletion- __. • It breaks off and all that information is now lost. A B C E F G H ABCDEFGH Deletion

  13. 11.3 Section Summary 6.3 – pages 296 - 301 Chromosomal Alterations • 2) Duplication (__)- When part of a chromatid breaks off and attaches to its sister chromatid. • The result is a duplication of genes on the __ chromosome. A B C D E F G H A B C B C D E F G H Insertion

  14. 11.3 Section Summary 6.3 – pages 296 - 301 Chromosomal Alterations • 3) Inversion- When part of a chromosome breaks off and __. A B C D E F G H A D C B E F G H Inversion

  15. 11.3 Section Summary 6.3 – pages 296 - 301 Chromosomal Alterations • 4) Translocation- When part of one chromosome breaks off and is added to __. G A B C D E F H W X A B C D E F G H Z W X Y Y Z Translocation

  16. 11.3 Section Summary 6.3 – pages 296 - 301 Causes of Mutations • 1) __ mutations: mutations that just seem to happen • How? • Errors in __ (mistake in base pairing) • Errors in __

  17. 11.3 Section Summary 6.3 – pages 296 - 301 Causes of Mutations • 2) __: Any agent that can cause a change in the __ (mutation) • These are environmental factors such as: • a) __: such as X rays cosmic rays, ultraviolet light, and nuclear radiation. • The energy they contain can damage or break apart __.

  18. 11.3 Section Summary 6.3 – pages 296 - 301 Causes of Mutations • b) __ mutagens: include dioxins, asbestos, benzene, and formaldehyde. • Usually cause substitution mutations • c) __ *__- Procedure used to identify mutagenic substances.

  19. 11.3 Section Summary 6.3 – pages 296 - 301 Repairing DNA • __ proofread the DNA and replace incorrect nucleotides with correct nucleotides. • However, the __ the exposure to a mutagen such as UV light, the __ likely is the chance that a mistake will not be corrected.

  20. Section 12.1 Summary – pages 309 - 314 Pedigrees illustrate inheritance • Pedigree: a graphic representation of __ inheritance. • Like a __. • It is a diagram made up of a set of __ that identifies individuals affected by the trait being studied, and family relationships.

  21. Section 12.1 Summary – pages 309 - 314 Male Parents Female Siblings Pedigreesillustrateinheritance Affected male Affected female Known heterozygotes for recessive allele Mating Death

  22. Section 12.1 Summary – pages 309 - 314 Pedigrees illustrate inheritance Female Male I 1 2 II 2 1 4 5 3 • In a pedigree, a __ represents a female; a __ represents a male. III 1 4 2 3 ? IV 5 3 4 2 1

  23. Section 12.1 Summary – pages 309 - 314 Pedigrees illustrate inheritance I 1 2 II 3 2 1 4 5 • Highlighted circles and squares represent individuals showing the trait being studied. III 1 4 2 3 ? IV 2 3 5 1 4

  24. Section 12.1 Summary – pages 309 - 314 Pedigrees illustrate inheritance I 1 2 II 1 2 4 3 5 • Circles and squares that are not highlighted designate individuals that do not show the trait. III 2 4 1 3 ? IV 3 4 5 1 2

  25. Section 12.1 Summary – pages 309 - 314 Pedigrees illustrate inheritance • A half-shaded circle or square represents a __: a heterozygous individual.

  26. Section 12.1 Summary – pages 309 - 314 Pedigrees illustrate inheritance • A horizontal line connecting a circle and a square indicates that the individuals are parents (__ line), and a vertical line connects parents with their offspring (__ line). I 1 2 II 4 2 3 1 5 III 1 4 2 3 ? IV 2 3 5 1 4

  27. Section 12.1 Summary – pages 309 - 314 Pedigrees illustrate inheritance • Each horizontal row of circles and squares in a pedigree designates a __, with the most recent generation shown at the bottom. I 1 2 II 3 1 2 4 5 III 1 2 4 3 ? IV 3 5 1 2 4

  28. Section 12.1 Summary – pages 309 - 314 Pedigrees illustrate inheritance • The generations are identified in sequence by __, and each individual is given an Arabic number. I 1 2 II 3 1 2 4 5 III 1 2 4 3 ? IV 3 5 1 2 4

  29. 11.3 Section Summary 6.3 – pages 296 - 301 Detecting Genetic Disorders • 1) __: an examination of a persons genetic makeup. • This may involve: • A) Blood test - looks for the presence or absence of certain __

  30. Detecting Genetic Disorders 11.3 Section Summary 6.3 – pages 296 - 301 • B) Karyotype- __. • Procedure: remove __ from a cell • stain and photograph chromosomes • cut out each chromosome • match it with its __

  31. 11.3 Section Summary 6.3 – pages 296 - 301 Detecting Genetic Disorders: In a fetus • 1) __- uses high-frequency sound waves to produce an image of a fetus on a moniter • image is called a __ • 2) Amniocentesis- __. • Use a needle and syringe to remove some amniotic fluid. • Make a __ and analyze.

  32. 11.3 Section Summary 6.3 – pages 296 - 301 Detecting Genetic Disorders: In a fetus • 3) Chorion villi sampling- analyze a sample of the chorion villi (tissue that grows between the __.) • villi has the same __as the fetus. • 4) __- a visual procedure for observing disorders in the fetus. • Uses an instrument called an __ • can: observe fetus’ development, take skin and blood samples for analysis, do blood transfusions, and remove excess fluid from the brian.

  33. Section 12.1 Summary – pages 309 - 314 Simple Recessive Heredity • Most genetic disorders are caused by __ alleles. 1) Cystic fibrosis • Due to a defective __ in the cell membrane. • Results in the formation and accumulation of thick __ in the lungs and digestive tract. • Common among __. (1 in 28 carries the allele, 1 in 2500 inherits the disorder) • Average lifespan: __ yrs.

  34. Section 12.1 Summary – pages 309 - 314 2) Tay-Sachs disease • Tay-Sachs (tay saks): a recessive disorder of the __. • Results in the absence of an __ that normally breaks down a __ produced and stored in tissues of the central nervous system. • Therefore, lipids accumulate in the cells.

  35. Section 12.1 Summary – pages 309 - 314 I 1 2 Typical Pedigree for II 1 2 4 3 Tay-Sachs III 3 1 2 IV 1

  36. Section 12.1 Summary – pages 309 - 314 3) Phenylketonuria • Phenylketonuria (fen ul kee tun YOO ree uh): (PKU) the absence of an __ that converts one amino acid, phenylalanine, to a different amino acid, tyrosine. • Phenylalanine and its by-products accumulate in the body resulting in severe damage to the __. • A PKU test is normally performed on all __ a few days after birth. • Infants affected by PKU are given a diet that is low in __ until their __ are fully developed.

  37. Section 12.1 Summary – pages 309 - 314 Phenylketonuria • New Problem: If a female who is homozygous recessive for PKU becomes __, the high phenylalanine levels in her blood can damage her __ - the developing baby. • This problem occurs even if the fetus is __ and would be phenotypically normal.

  38. Section 12.1 Summary – pages 309 - 314 Phenylketonuria Phenylketonurics: Contains Phenylalanine

  39. Section 12.1 Summary – pages 309 - 314 Simple Dominant Heredity • A single dominant allele inherited from __ parent is all that is needed for a person to show the dominant trait.

  40. Section 12.1 Summary – pages 309 - 314 Simple dominant traits: • 1) __ • 2) widow’s __ • 3) hitchhiker’s thumb • 4) almond shaped __ • 5) thick lips • 6) presence of __ on the middle section of you fingers

  41. Section 12.1 Summary – pages 309 - 314 Huntington’s disease • A __ genetic disorder • Caused by a rare __ allele. • Results in a breakdown of certain areas of the __. • Symptoms: __ and irritability, eventually lose of __ control, uncontrollable physical __, severe mental illness, and eventually __.

  42. Section 12.1 Summary – pages 309 - 314 Huntington’s disease • Usually occurs between the ages of __ • An individual may already have had children before knowing whether he or she is affected. • __: a short section of __ that indicates the presence of an allele that codes for a trait. • __of people with this marker have a chance of developing HD • can test before they have __.

  43. Section 12.1 Summary – pages 309 - 314 Typical Pedigree of Huntington’s Disease I 2 1 II 1 2 3 4 5 III 1 2 3 4 5

  44. Section 1 Check Question 1 What does this pedigree tell you about those who show the recessive phenotype for the disease? I 1 2 II 1 2 4 3 III 3 1 2 IV 1

  45. Section 1 Check I The pedigree indicates that showing the recessive phenotype for the disease is __. 1 2 II 1 2 4 3 III 3 1 2 IV 1

  46. Section 12.2 Summary – pages 315 - 322 Genetic Patterns • Thomas Hunt __ (early 1900’s) • Began a series of breeding experiments with Drosophila melanogaster (__) Why use fruit flies? • Easy to maintain in a laboratory • have a generation time of only __ days • produce __ of offspring from each mating • have easily distinguishable __ characteristics • have only __ chromosomes

  47. Section 12.2 Summary – pages 315 - 322 Genetic Patterns • He discovered that __ pair of chromosomes were different in males and females. • In females: all pairs were __ • In males: the __ pair was different • He called the large chromosome in the 4th pair the “__” chromosome and he called the short hooked one the “__” chromosome. • The same applies to __. • Other organisms differ

  48. Section 12.2 Summary – pages 315 - 322 Sex determination • In humans the __ number of chromosomes is 46, or 23 pairs. • __ chromosomes: Chromosomes that determine an individual’s sex. They are the __ pair in humans and they differ in males and females. • __: A chromosome that is not a sex chromosome. There are __ pairs of homologous autosomes in humans. They all look alike.

  49. Section 12.2 Summary – pages 315 - 322 Sex determination • If you are __, your 23rd pair of chromosomes are homologous, __. X X Female • If you are __, your 23rd pair of chromosomes __, look different. X Y Male

  50. Section 12.2 Summary – pages 315 - 322 Sex determination • Males: Produce two kinds of __, X and Y. • Females: Produce only __ gametes. • It is the __ gamete that determines the sex of the offspring.

More Related