2 How does a mutation affect the life of an organism? ESSENTIAL QUESTION:How does a mutation affect the life of an organism?What are some options that scientists have to predict the possibility of genetic diseases in infants?Do all mutations cause a change in the physical appearance of an organism?
3 REVIEW Changes in the gene code _______________ that is made A change in the genetic code =________________change the proteinmutation
4 Many genetic ___________ result from changes in the DNA code so _________________ proteins are produced.DISORDERSNON-FUNCTIONING
5 CHROMOSOMAL MUTATIONS KINDS OF MUTATIONSMutations that produce changes in a single gene =_________________Mutations that produce changes in whole chromosomes = _____________________GENE MUTATIONSCHROMOSOMAL MUTATIONS
6 ____________________________: Change in the ______________ or ____________ of chromosomesCHROMOSOMAL MUTATIONSstructurenumberEx:Inversion of chromosome 12
7 Do you recognize this family? *Hint: They are from a TV show 7
8 facial features, hair color etc. They are the Roloff family from TLC’s show Little People Big World How are the members of this family the same? How are they different?SameDifferentfacial features, hair color etc.heightSome family members (including the parents) exhibit the characteristic short stature of Achondroplasia, a dominant genetic disorder that results in a form of dwarfism.8
9 EXPLORATION ACTIVTIY: How is it possible for Matt and Amy (the parents) to have a child like Zach with Achondroplasia, dominant genetic disorder, and three children who do not have the disease?
10 DID YOU QUICKLY THINK, Since some of the Roloff children do not exhibit dwarfism, what do we know about Matt and Amy’s genes for Achondroplasia?THAT’S RIGHT!!!Matt and Amy both have an Aa genotype. This would allow them to have children who exhibit dwarfism as well as children of normal height.Dwarfism: Aa or AANormal height: aa10
11 DID YOU KNOW?1. As the occurrence of infectious and nutritional diseases decreases in developed countries, genetic diseases have come to the forefront.2. At least one-third of the children in pediatric hospitals are there because of hereditary disorders.3. Chromosomal mutations account for about half of all first-trimester miscarriages.4. A total of about 7% of the population suffers from some type of genetic disorder.
12 GENETIC DISEASES: inherited disorders reflecting gene mutations or abnormalities in chromosome structure or number, which result in a functional or anatomical change.Examples: -changes that cause deformities (cleft lip) -metabolic change (phenylketonuria “pku”) -structural changes (albinisim)
13 How are genetic disorders transmitted or inherited? Genetic diseases can be inherited in a manner similar to that of normal traits. These diseases include single-gene disorders that are autosomal or sex-linked.AutosomalSex-linkedmeans that the gene is present in a chromosome pair other than the sex chromosomesmeans that the gene is located on a sex chromosome
14 Types of Genetic Diseases Sex-linkedAutosomal recessiveAutosomal dominance
15 Sex-Linked GenesPattern of inheritance is located on the X- chromosome or the Y- chromosomeY is much smallerTherefore, there are more X-linked disorders/traits
16 What numbers do you See? Ex. Colorblindness X-linked disorder Most common in ?Males (1/10)Females (1/100)
17 AUTOSOMAL RECESSIVE DISORDER A mutation that causes a protein to be NON-FUNCTIONAL would appear _________ to the normal working allele.RecessiveEXAMPLES:Phenylketonuria (PKU)Tay-Sachs DiseaseCystic Fibrosis
18 Ex: Phenylketonuria (PKU) The following is simply an example to assist with your understanding:Ex: Phenylketonuria (PKU)CAUSE: Mutation in gene for an ___________ that __________ an ___________ called phenylalanineBuild up causes ________________________ENZYMEbreaks downamino acidXXMENTAL RETARDATION
19 Phenylketonuria (PKU) ALLtested____ babies are ________for PKU before theyleave the hospital.Treatment: Need a diet _____________________ to extend life and ______________ mental retardationIf phenylalanine is an _____________,what type of foods should PKU patients avoid? __________________LOW in phenylalaninePREVENTamino acidPROTEINS !
20 Autosomal Dominant Disorders A mutation that codes for a new protein whose action masks the normal allele appears as a _____________ mutation. HENCE,_________________________ GENETIC DISORDERS:Examples:Huntington’s DiseaseAchondroplasia (Roloff family )dominantDOMINANT
21 What can you tell by this karyotype? Analyzing Karyotypes
22 Karyotype Organized profile of a human’s chromosomes Chromosomes are paired bycentromere locationbanding patternSize
23 REVIEW Humans have two sex chromosomes and _____ autosomes Chromosomes that determine the sex of an organism = _________________All other chromosomes = _________________Sex chromosomesautosomesHumans have two sex chromosomesand _____ autosomesXY44
25 What can you tell by analyzing this karyotype? Analyzing Karyotypes
26 Karyotype Analysis: Chromosomal Disorders Nondisjunction- occurs when either homologous chromosome fails to separate during meiosisResults abnormal # of chromosomes in gametesTrisomy = 1 extra homologous chromosome (3)Polysomy = more than 1 extraMonosomy = only 1 chromosomeExamples: Down syndrome, Klinefelter syndrome, Turner Syndrome
27 Find the chromosome that results from nondisjunction below That’s right, the sex chromosome has an extra Y. Trisomy, polysomy, or monosomy?
28 ELABORATION ACTIVITYPredict the genetic disorder by constructing a karyotype.