TOPIC 3.4 - INHERITANCE

3.4 – A – Inheritance & Alleles

IB BIO – 3.4 Gregor Mendel was an Austrian monk who is known as the father of genetics. He noted that pea plants in his garden had characteristics that were sometime passed on to offspring. 3 Understandings U1: Mendel discovered the principles of inheritance with experiments in which large numbers of pea plants were crossed. Key Terms Gregor Mendel http://res.cloudinary.com/dk-find-out/image/upload/q_80,w_1440/A-Alamy-DG0PF5_bnhdua.jpg

IB BIO – 3.4 To study how pea plants pass on traits, he bred plants for that were pure for seven traits. Those traits included: 4 Understandings U1: Mendel discovered the principles of inheritance with experiments in which large numbers of pea plants were crossed. Key Terms Gregor Mendel http://archive.cnx.org/resources/fa6f545cec588d620656d63cefaa1ad4c528df03/Figure_08_01_03.jpg

IB BIO – 3.4 Then, he crossed large numbers of plants with different characteristics to determine which traits would appear in offspring. His observations allowed him to discover the principles of inheritance which are discussed in this topic. *See the video at the end of this Topic for further explanation 5 Understandings U1: Mendel discovered the principles of inheritance with experiments in which large numbers of pea plants were crossed. Key Terms Gregor Mendel http://www.grossmont.edu/people/bonnie-yoshida-levine/images/images/Genetics/MendelPeas.jpg

IB BIO – 3.4 As discussed in Topic 3.3, meiosis results in haploid gametes, which only contain half the chromsomes and one allele of each gene. 6 Understandings U2: Gametes are haploid so contain only one allele of each gene. U3: The two alleles of each gene separate into different haploid daughter nuclei during meiosis. A zygote results when two gametes fuse together. It is able to grow and develop into an adult organism. Key Terms Haploid / Diploid http://www.mun.ca/biology/desmid/brian/BIOL2060/BIOL2060-20/20_14.jpg

IB BIO – 3.4 During gamete production, the two alleles for a gene segregate into different daugher nuclei. The overall combination of alleles in the resulting cells is random, promoting variation. 7 Understandings U2: Gametes are haploid so contain only one allele of each gene. U3: The two alleles of each gene separate into different haploid daughter nuclei during meiosis. Key Terms http://www.mun.ca/biology/desmid/brian/BIOL2060/BIOL2060-20/20_14.jpg

IB BIO – 3.4 When gametes fuse, the resulting diploid zygote has two alleles for every gene. These alleles may be the same or different. Heterozygous – the two alleles for a gene are different Homozygous – the two alleles for a gene are the same 8 Understandings U4: Fusion of gametes results in diploid zygotes with two alleles of each gene that may be the same allele or different alleles. Key Terms https://www.genome.gov/dmd/previews/85182_large.jpg

IB BIO – 3.4 Practice 9 Understandings U4: Fusion of gametes results in diploid zygotes with two alleles of each gene that may be the same allele or different alleles. Determine whether the following are Heterozygous or Homozygous Key Terms http://ysalazar.weebly.com/uploads/4/2/0/8/42086445/beginning_genotype_phenotypes.png

IB BIO – 3.4 When discussing inherited traits, two important terms are used: Genotype – the combination of alleles an organism has, typically shown using pairs of letters. Phenotype – the observable physical characteristics 10 Understandings U5: Dominant alleles mask the effects of recessive alleles but co-dominant alleles have joint effects. Key Terms Genotype Phenotype http://2.bp.blogspot.com/--L23zo3HS1Q/UDe7eJfgGBI/AAAAAAAAAL4/4iPO3ncnC8Y/s1600/25_environmental_variation.gif

IB BIO – 3.4 Some alleles are able to mask the effects of others when they are present. These are called dominant alleles and are represented using upper case letters (A = purple). Recessive alleles are those that are masked by dominant alleles. They are represented using lower case letters (a = white). 11 Understandings U5: Dominant alleles mask the effects of recessive alleles but co-dominant alleles have joint effects. Key Terms Dominant Allele Recessive Allele http://www.cubocube.com/files/images/opengenetics/chapter3/image3.png

Determine the phenotype in the following examples IB BIO – 3.4 Practice 12 Understandings U5: Dominant alleles mask the effects of recessive alleles but co-dominant alleles have joint effects. Determine the phenotype in the following examples Key Terms http://ysalazar.weebly.com/uploads/4/2/0/8/42086445/beginning_genotype_phenotypes.png

IB BIO – 3.4 Co-dominance occurs when co-dominant alleles are present. These have joint effects and so are both seen in the phenotype. In the example here, red and white alleles mix to form a pink flower. 13 Understandings U5: Dominant alleles mask the effects of recessive alleles but co-dominant alleles have joint effects. Key Terms Co-dominant Allele http://www.cubocube.com/files/images/opengenetics/chapter3/image3.png

VIDEOS TedEd – How Mendel’s Pea Plants Helped Us Understand Genetics IB BIO – 3.4 TedEd – How Mendel’s Pea Plants Helped Us Understand Genetics CrashCourse - Heredity 14 VIDEOS

IB BIO – 3.4 Outline Mendel’s use of peas in discovering principles of genetics. Describe the segregation of alleles during meiosis. Define the following: - Genotype - Phenotype - Heterozygous - Homozygous Compare the effects of dominant and recessive alleles. Describe co-dominance using an example. 15 REVIEW

3.4 – B – Monohybrid Crosses

IB BIO – 3.4 Punnett grids are a tool that can be used to predict the outcomes of monohybrid crosses. These are crosses that involve the study of a single trait. 17 Skills S1: Construction of Punnett grids for predicting the outcomes of monohybrid genetic crosses. Key Terms Punnett Grid Monohybrid Cross http://1.bp.blogspot.com/-vX7FvvV9e6o/VkbmOhmc8tI/AAAAAAAAAus/-PivO6ldyF8/s1600/monohybrid-cross-punnett-square.png

IB BIO – 3.4 Using Punnett Grids 18 Skills S1: Construction of Punnett grids for predicting the outcomes of monohybrid genetic crosses. Determine the genotype of the parents and write them as a cross (i.e. Rr x Rr). _______ X _________ Write the genotypes of the parents on the top and left side of the Punnett grid. There should be one allele per box on each side. Key Terms Punnett Grid Monohybrid Cross https://www.biologycorner.com/resources/punnett_1_answers.gif

IB BIO – 3.4 Using Punnett Grids 19 Skills S1: Construction of Punnett grids for predicting the outcomes of monohybrid genetic crosses. Use the genotypes on the outside of the grid to fill in the squares with completed genotypes. Determine the number of each type of genotype and phenotype. This can be used to predict ratios of offspring. Key Terms Punnett Grid Monohybrid Cross https://www.biologycorner.com/resources/punnett_1_answers.gif

https://d2gne97vdumgn3.cloudfront.net/api/file/iOA8caDKSK2Th0aVHRNg IB BIO – 3.4 Punnett Grid Example 1 20 Skills S1: Construction of Punnett grids for predicting the outcomes of monohybrid genetic crosses. A heterozygous yellow pea plant is crossed with a homozygous green pea plant. What percentage of offspring will be yellow? Y = yellow (dominant) y = green (recessive) Yy x yy Genotype: - 50% yy - 50% Yy Phenotype: - 50% green - 50% yellow Key Terms Punnett Grid Monohybrid Cross https://d2gne97vdumgn3.cloudfront.net/api/file/iOA8caDKSK2Th0aVHRNg

BB x Bb IB BIO – 3.4 Punnett Grid Example 2 21 Skills S1: Construction of Punnett grids for predicting the outcomes of monohybrid genetic crosses. A heterozygous brown-eyed man reproduces with a homozygous brown-eyed woman. What portion of offspring will be blue-eyed? B = brown (dominant) b = blue (recessive) BB x Bb Genotype: - 50% Bb - 50% BB Phenotype: - 100% brown - 0% blue Key Terms Punnett Grid Monohybrid Cross https://upload.wikimedia.org/wikipedia/commons/thumb/8/89/Punnett_homobrown_x_hetero.svg

IB BIO – 3.4 Human blood types are determined by the presence of proteins on the surface of red blood cells. The blood types of parents’ offspring can be predicted using monohybrid Punnett squares. 22 Applications A1: Inheritance of ABO blood groups. Key Terms Blood Type https://upload.wikimedia.org/wikipedia/commons/thumb/3/32/ABO_blood_type.svg/2000px-ABO_blood_type.svg.png

IB BIO – 3.4 Blood Type Genotypes 23 There are four blood types in humans: A, B, AB and O. The genotype for each is shown in the table below. Each allele is represented as an I with a superscript or i (absence of protein). Applications A1: Inheritance of ABO blood groups. Key Terms Blood Type http://yellowbicyclestudio.com/Table%207-2.jpg

Determining Blood Type – Example 1 IB BIO – 3.4 Determining Blood Type – Example 1 24 Punnett grids for blood types are used the same way as other monohybrid crosses. For example, this grid shows the results of crossing two AB individuals: IAIB x IAIB Applications A1: Inheritance of ABO blood groups. IA IB Key Terms Blood Type

Determining Blood Type – Example 1 IB BIO – 3.4 Determining Blood Type – Example 1 25 Punnett grids for blood types are used the same way as other monohybrid crosses. For example, this grid shows the results of crossing two AB individuals: IAIB x IAIB Genotypes: - 50% IAIB - 25% IAIA - 25% IBIB Phenotypes: - 50% AB - 25% A - 25% B Applications A1: Inheritance of ABO blood groups. IA IB IAIA IAIB IBIB Key Terms Blood Type

Determining Blood Type – Example 2 IB BIO – 3.4 Determining Blood Type – Example 2 26 If a heterozygous Type A male mates with a heterozygous Type B female, what percentage of the offspring will have Type O blood? IAi x IBi Applications A1: Inheritance of ABO blood groups. IB i IA Key Terms Blood Type

Determining Blood Type – Example 2 IB BIO – 3.4 Determining Blood Type – Example 2 27 If a heterozygous Type A male mates with a heterozygous Type B female, what percentage of the offspring will have Type O blood? IAi x IBi Genotypes: - 25% IAIB - 25% IAi - 25% IBi - 25% ii Phenotypes: - 25% AB - 25% A - 25% B - 25% O Applications A1: Inheritance of ABO blood groups. IB i IA IAIB IAi IBi ii Key Terms Blood Type

VIDEOS Learn Biology: How to Set Up a Punnett Square IB BIO – 3.4 Learn Biology: How to Set Up a Punnett Square SciShow: What are Blood Types TedEd: Why Do Blood Types Matter 28 VIDEOS

IB BIO – 3.4 Outline the use of Punnett Squares in predicting the outcomes of monohybrid crosses. If wrinkled pea plant (Ww) is crossed with a smooth pea plant (ww), what percentage of the offspring would be smooth. If a Type O woman mated with a Type AB male, what percentage of their offspring would have: - Type O Blood? - Type AB Blood? - Type A Blood? 29 REVIEW

3.4 – C –Diseases & Sex-Linkage

IB BIO – 3.4 Genetic diseases are disorders that are caused by errors in the genome. Most result from recessive alleles on the autosomal chromosomes (1-22), though some are the result of dominance. Many diseases have been found in humans, but most are very rare. Improving genetic techniques are allowing scientistics to identify and study more. 31 Understandings U6: Many genetic diseases in humans are due to recessive alleles of autosomal genes, although some diseases are due to dominant or co-dominant alleles. U8: Many genetic diseases have been identified in humans but most are very rare. http://www.institut-biotherapies.fr/wp-content/uploads/2013/01/Exp_transmission_ang.jpg

IB BIO – 3.4 Cystic fibrosis is a genetic diseases that results from recessive allele on chromosome #7. The allele produces Cl- ion channels that increases chloride levels in sweat and decreases levels in mucus. This interferes with osmosis, which causes a buildup of thick mucus outside of the cell membranes. 32 Applications A3: Inheritance of cystic fibrosis and Huntington’s disease. Key Terms Cystic Fibrosis http://learn.genetics.utah.edu/content/disorders/singlegene/cf/images/cf-channel.jpg

IB BIO – 3.4 Sticky mucus builds up in the lungs, which causes: Frequent infections Trouble Breathing The pancreatic duct is also blocked, which causes: Trouble digesting food Abnormal pancreas activity/function 33 Applications A3: Inheritance of cystic fibrosis and Huntington’s disease. Key Terms Cystic Fibrosis http://learn.genetics.utah.edu/content/disorders/singlegene/cf/images/cf-channel.jpg

IB BIO – 3.4 34 Applications A3: Inheritance of cystic fibrosis and Huntington’s disease. Key Terms Cystic Fibrosis http://i0.wp.com/beatingpancreatitis.com/wp-content/uploads/2015/08/cystic-fibrosis-chronic-pancreas-inflammation.jpg

IB BIO – 3.4 Since cystic fibrosis is an autosomal recessive disease, Punnett grids can be used to determine how the trait will pass from parent to offspring. Chances of inheriting the disease are not related to sex. 35 Applications A3: Inheritance of cystic fibrosis and Huntington’s disease. Key Terms Cystic Fibrosis https://upload.wikimedia.org/wikipedia/commons/thumb/3/3e/Autorecessive.svg

IB BIO – 3.4 Huntington’s disease (HD) is a genetic disease caused by a dominant allele on chromosome #4. Because the allele is dominant, any individual who has even one copy of it will be affected. 36 Applications A3: Inheritance of cystic fibrosis and Huntington’s disease. Key Terms Huntington’s Disease http://hdsa.org/wp-content/themes/hdsa/images/img_HD2.png

IB BIO – 3.4 The HD allele causes degenerative changes in the brain, which typically starts between ages 30-50. Eventually, affected individuals require nursing care and succumb to infectious diseases. 37 Applications A3: Inheritance of cystic fibrosis and Huntington’s disease. Key Terms Huntington’s Disease http://healthlifemedia.com/healthy/wp-content/uploads/2016/09/HD-n-Normal-Brain.jpg

IB BIO – 3.4 Punnett grids like the one here can be used to predict the likelihood of parents passing on Huntington’s disease. Like cystic fibrosis, inheritance of the condition is independent of sex. 38 Applications A3: Inheritance of cystic fibrosis and Huntington’s disease. Key Terms Huntington’s Disease http://www.passmyexams.co.uk/GCSE/biology/images/inheritance-chart-huntingtons.jpg

IB BIO – 3.4 Other genetic diseases can be linked to sex, which means the associated alleles are located on the sex chromosomes (23). As a result, the sex of offspring can determine the likelihood of inheriting these disease. Two common examples include: Red-Green Color Blindness Hemophilia 39 Understandings U7: Some genetic diseases are sex-linked. The pattern of inheritance is different with sex-linked genes due to their location on sex chromosomes. Key Terms Sex-linked https://amasianv.files.wordpress.com/2012/08/sex-chromosomes1.jpg

IB BIO – 3.4 Punnett grids can be used to determine the inheritance of sex- linked traits. The sex chromosomes of the parents are used instead of autosomal alleles (male = XX, female = XY). The general setup is shown here: 40 Understandings U7: Some genetic diseases are sex-linked. The pattern of inheritance is different with sex-linked genes due to their location on sex chromosomes. X XX Y XY Key Terms Sex-linked https://amasianv.files.wordpress.com/2012/08/sex-chromosomes1.jpg

Red-Green Colour Blindness IB BIO – 3.4 Red-green color blindness is a sex-linked condition caused by a recessive allele on the X chromosome. Since males have only one X, they are more likely to be affected than women, who have two alleles for each X-linked gene. 41 Applications A2: Red-green colour blindness and hemophilia as examples of sex-linked inheritance. Key Terms Red-Green Colour Blindness https://upload.wikimedia.org/wikipedia/commons/thumb/c/c7/X-linked_recessive.svg/

Red-Green Colour Blindness IB BIO – 3.4 Those with the disease have mutated genes for red or green color receptors in the retina. As a result, they are unable to properly distinguish the two colors. 42 Applications A2: Red-green colour blindness and hemophilia as examples of sex-linked inheritance. Key Terms Red-Green Colour Blindness https://upload.wikimedia.org/wikipedia/commons/thumb/c/c7/X-linked_recessive.svg/

XBXb XBY XbXb XbY Xb Y XB XBXb x XbY IB BIO – 3.4 Sex-Linked Inheritance Example 1 43 If a male with color blindness mates with a carrier female, what percentation of their sons will have the trait? B = normal b = color blind XBXb x XbY Sons: - 50% XBY (normal) - 50% XbY (color blind) Daughters: - 50% XBXb (carrier) - 50% XbXb (color blind) Applications A2: Red-green colour blindness and hemophilia as examples of sex-linked inheritance. Xb Y XB XBXb XBY XbXb XbY Key Terms Red-Green Colour Blindness https://upload.wikimedia.org/wikipedia/commons/thumb/c/c7/X-linked_recessive.svg/

IB BIO – 3.4 Hemophilia is another genetic disease caused by a recessive allele on the X-chromosome. The disease prevents the ability to form Factor VIII, which is vital for blood clotting. It is life-threatening. 44 Applications A2: Red-green colour blindness and hemophilia as examples of sex-linked inheritance. Key Terms Hemophilia https://ghr.nlm.nih.gov/art/large/impaired-blood-clotting-in-hemophilia.jpeg

IB BIO – 3.4 Individuals with this disorder typically have a life expectancy of about 10 years if left untreated. Treatment involves infusing Factor VIII isolated from donor blood sources. 45 Applications A2: Red-green colour blindness and hemophilia as examples of sex-linked inheritance. Key Terms Hemophilia http://www.koate-dviusa.com/filebin/images/patient/replacement-therapy.jpg

Sex-Linked Inheritance Example 2 IB BIO – 3.4 Sex-Linked Inheritance Example 2 46 If a female with a hemophilia mates with a normal male, what percentage of their daughters will have the trait? H = normal h = hemophilia XhXh x XHY Sons: - 100% XhY (hemophiliac) Daughters: - 100% XHXh (carrier) - 0% XhXh (hemophiliac) Applications A2: Red-green colour blindness and hemophilia as examples of sex-linked inheritance. XH Y Xh XHXh XhY Key Terms Hemophilia https://upload.wikimedia.org/wikipedia/commons/thumb/c/c7/X-linked_recessive.svg/

Sex-Linked Inheritance Example 3 IB BIO – 3.4 Sex-Linked Inheritance Example 3 47 If a famale carrier for hemophilia mates with an affected male, what percentage of their daughters will have the trait? H = normal h = hemophilia XHXh x XhY Sons: - 50% XHY (normal) - 50% XhY (hemophiliac) Daughters: - 50% XHXh (carrier) - 50% XhXh (hemophiliac) Applications A2: Red-green colour blindness and hemophilia as examples of sex-linked inheritance. Xh Y XH XHXh XHY XhXh XhY Key Terms Hemophilia https://upload.wikimedia.org/wikipedia/commons/thumb/c/c7/X-linked_recessive.svg/

REVIEW Define genetic disease. IB BIO – 3.4 Define genetic disease. Outline the inheritance of Huntington’s disease and cystic fibrosis. Define sex-linked disease. Compare autosomal and sex-linked traits. Outline the inheritance of hemophilia and red-green colorblindness. 48 REVIEW

3.4 – D – Pedigrees

IB BIO – 3.4 Pedigrees are charts that show the passing of traits through a family. The typical conventions for constructing them are: 50 Skills S3: Analysis of pedigree charts to deduce the pattern of inheritance of genetic diseases. = male = affected male I, II, III = generation = female = affected female = mating Key Terms Pedigree https://www.mun.ca/biology/scarr/PTC_tasting_2.gif

IB BIO – 3.4 Patterns observed in pedigrees can be used to determine the type of disease/trait that is being studied. The typical possibilities are: - Autosomal recessive - Autosomal dominant - X-linked recessive - X-linked dominant 51 Skills S3: Analysis of pedigree charts to deduce the pattern of inheritance of genetic diseases. Autosomal Recessive Traits can skip generations and appear later Males and females are affected equally Key Terms Pedigree https://www.mun.ca/biology/scarr/PTC_tasting_2.gif

IB BIO – 3.4 Autosomal Recessive 52 Determine the genotypes of as many members in this pedigree as possible. The genotypes of some members cannot be determined. Skills S3: Analysis of pedigree charts to deduce the pattern of inheritance of genetic diseases. aa Aa or AA Aa Key Terms Pedigree https://sites.google.com/site/pedigreesforpredictingtraits/_/rsrc/1353457584042/volunteer-information/Recessive_Pedigree_Cyc_Fib_Blank.PNG

IB BIO – 3.4 Autosomal Dominant 53 Skills S3: Analysis of pedigree charts to deduce the pattern of inheritance of genetic diseases. Traits do not normally skip generations Unaffected members are homozygous recessive Traits affect males and females equally Aa aa Key Terms Pedigree http://moodle2.rockyview.ab.ca/pluginfile.php/64202/mod_book/chapter/25853/biology_30/images/m6/b30_m6_042_l.jpg

IB BIO – 3.4 XbXb XBY XbY XBXb X-linked Recessive 54 Skills S3: Analysis of pedigree charts to deduce the pattern of inheritance of genetic diseases. Traits tend to affect males more than females Unaffected males have the normal X allele XbXb XBY XbY XBXb Key Terms Pedigree https://migrc.org/library/X-linkedRecessive.gif

IB BIO – 3.4 XBXb XbY XBY XbXb XbY X-linked Dominant 55 Skills S3: Analysis of pedigree charts to deduce the pattern of inheritance of genetic diseases. Traits affect all individuals that have the dominant allele Homozygous affected females pass trait on to all offpsring XBXb XbY XBY XbXb XbY Key Terms Pedigree https://migrc.org/Library/X-linkedDominant.gif

IB BIO – 3.4 Determine the type of characteristic and the genotypes in the following pedigree: 56 REVIEW Autosomal Dominant https://migrc.org/Library/AutosomalDominant.gif

IB BIO – 3.4 Determine the type of characteristic and the genotypes in the following pedigree: 57 REVIEW X-linked Dominant http://www.cubocube.com/files/images/opengenetics/chapter5/image5.png

3.4 – E – Genetic Mutations

IB BIO – 3.4 As discussed in Topic 3.1, mutations are changes in DNA that can result in new alleles. The rate of mutation can be affected by two types of factors: radiation & mutagenic chemicals. 59 Understandings U9: Radiation and mutagenic chemicals increase the mutation rate and can cause genetic diseases and cancer. Key Terms http://www.yourgenome.org/sites/default/files/illustrations/diagram/dna_mutations_point_mutation_yourgenome.png

IB BIO – 3.4 Radiation increases the rate of mutation by adding enough energy to cause chemical changes in DNA molecules. This includes ultraviolet radiation, X-rays and radioactive materials. 60 Understandings U9: Radiation and mutagenic chemicals increase the mutation rate and can cause genetic diseases and cancer. Key Terms Radiation https://upload.wikimedia.org/wikipedia/commons/thumb/f/fd/DNA_UV_mutation.svg

IB BIO – 3.4 Mutagenic chemicals are those that cause chemical changes to the DNA sequence. Where as radiation is energy, mutagenic chemicals are made of matter. Such chemicales include those found in: Tobacco Mustard gas Nitrous Acid 61 Understandings U9: Radiation and mutagenic chemicals increase the mutation rate and can cause genetic diseases and cancer. Key Terms Mutagenic Chemicals https://upload.wikimedia.org/wikipedia/commons/thumb/f/fd/DNA_UV_mutation.svg

IB BIO – 3.4 Mutations that occur in adult cells can causes diseases such as cancer, but are not passed on to offspring. However, mutations in cells that develop into gametes can be inherited by offspring. So, mutations in gametes are the origin of genetic diseases. 62 Understandings U9: Radiation and mutagenic chemicals increase the mutation rate and can cause genetic diseases and cancer. Key Terms http://biology-forums.com/gallery/33_25_06_11_10_06_06.jpeg

IB BIO – 3.4 Hiroshima was one of two Japanese cities hit with a number bomb during World War II. The explosion released radioactive isotopes into the environment which the people were then exposed to. 63 Applications A4: Consequences of radiation after nuclear bombing of Hiroshima and accident at Chernobyl. Key Terms Hiroshima http://cbsnews1.cbsistatic.com/hub/i/2016/05/25/b4c5ee68-36a2-493b-8da9-949cce03d7a2/rtsf5h2cr.jpg

IB BIO – 3.4 Most who survived the blast died within a few months due to the radiation exposure. The health of survivors were tracked for over 50 years. They showed a higher occurrence of tumors compared to control populations In the following years, there was also an increase in mutations, causing: Stillbirths Malformations Deaths 64 Applications A4: Consequences of radiation after nuclear bombing of Hiroshima and accident at Chernobyl. Key Terms Hiroshima http://hiroshima.australiandoctor.com.au/wp-content/uploads/2015/07/1950s-3318250_Getty.jpg

IB BIO – 3.4 In 1986, a nuclear power plant in Chernobyl, Ukraine released radioactive isotopes after an explosion in its nuclear core. 65 Applications A4: Consequences of radiation after nuclear bombing of Hiroshima and accident at Chernobyl. Key Terms Chernobyl https://cdn.theatlantic.com/assets/media/img/photo/2011/03/the-chernobyl-disaster-25-years-ago/c02_05010183/main_1200.jpg

IB BIO – 3.4 Over 6 tonnes of radioactive material was released in the atmosphere, which had widespread and severe effects: 66 Applications A4: Consequences of radiation after nuclear bombing of Hiroshima and accident at Chernobyl. 4 km2 of downwind forest browned and died Local cattle died from damaged thyroids After humans left the area, local wildlife thrived nearby Bioaccumulation of radioactive materials was seen across Europe More than 6,000 cases of thyroid cancer were reported Key Terms Chernobyl https://upload.wikimedia.org/wikipedia/commons/thumb/2/23/Chernobyl_radiation_map_1996.svg

IB BIO – 3.4 PBS News: Health Effects of Hiroshima and Nagasaki Atomic Bombings Still Carefully Tracked Veritasium: A Walk Around Chernobyl Euronews: Chernobyl – 30 Years on, Health Issues Remain NYT: The Animals of Chernobyl 67 VIDEOS

IB BIO – 3.4 List two examples of the following: - Mutation-causing radiation - Mutagenic chemicals Outline consequences of the following events: - Nuclear bombing of Hiroshima - Chernobyl Power Plant Accident 68 REVIEW