Extra Review Practice Biology Test Genetics - Key

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1 Mendel fill in he blanks: Exra Review Pracice Biology es Geneics - Key Mendel was an Ausrian monk who sudied geneics primarily using _pea plans. He sared wih plans ha produced offspring wih only one from of a rai; hese were called rue or _pure breeding plans. hrough breeding wo pure plans wih differen phenoypes, like all and shor, he discovered how rais could skip _generaions and how recessive alleles could ge masked. One of he hings Mendel discovered was he Law of Segregaion. his law saes ha alleles of a gene separae from each oher during _meiosis so only one allele for a paricular gene is in each gamee cell. Anoher hing Mendel noiced is ha when he crossed peas wih wo conrasing forms of he rai, for example all vs. shor and round vs. wrinkled, he inheriance of one rai didn influence he inheriance of he oher. So he oher law ha Mendel discovered was he Law of _Independen Assormen_. his law saes ha he inheriance of one rai does no have o deermine he rai of anoher, for example his all pea plans didn always have o have round seeds also. Generaions Pea Recessive Pure Segregaion Meiosis Gamee Independen Assormen Monohybrid Crosses and Basics Fill in he blanks below: Every person has _46 chromosomes ha conain many genes. _alleles are differen versions of a gene and based on which ones you inheri cerain rais will be expressed. he _genoype of an organism represens is geneic composiion (he alleles you acually inheri), he phenoype of an organism reflecs all he rais ha are acually expressed (wha you physically see). You have wo alleles for each rai, if you have wo dominan alleles you are _homozygous dominan, if you have wo recessive alleles you are homozygous recessive, if you have wo differen alleles you are heerozygous. In simple geneic problems someone who is heerozygous will show he dominan rai because i masks he recessive allele. When sudying he inheriance of alleles a monohybrid cross involves one rai or gene, while a _dihybrid cross involves sudying wo genes or rais a he same ime. Homozygous Dominan Alleles Phenoype Heerozygous Dihybrid Homozygous Recessive Genoype Dominan Monohybrid 46

2 Creae monohybrid crosses ha sudy heigh in pea plans. all pea plans () are dominan o shor () pea plans. 1. Se up a cross beween wo heerozygous parens. Show he Punne square below hen answer he following quesions: a. Wha is he genoypic raio: 1 : 2 : 1 b. Wha is he phenoypic raio: 3 all: 1 shor c. Wha percen chance will he offspring be all? 75% d. Wha percen chance would he offspring be homozygous dominan? 25% e. Wha percen change would he offspring be heerozygous? 50% 2. Se up a cross beween a heerozygous paren and a homozygous recessive paren. Show he Punne square below hen answer he following quesions: a. Wha is he genoypic raio: 2 : 2 OR 1:1 b. Wha is he phenoypic raio: 2 all: 2 Shor OR 1:1 c. Wha percen chance will he offspring be all? 50% d. Wha percen chance would he offspring be homozygous dominan? 0% e. How many differen phenoypes are possible beween hese parens? wo, all and shor f. How many differen genoypes are possible beween hese parens? wo, and

3 3. If wo parens are carriers for a disorder, wha does ha mean abou heir genoype? Wha does i mean abou he disorder? Wha is he likelihood ha even hough hey don express he disorder heir child would? If hey are carriers hey mus be heerozygous so if we were using s. If hey are carriers ha means he disorder mus be recessive, because if i was dominan hen hey would jus express he disorder carriers don express he disorder, jus carrier he recessive allele for i so hey could poenially pass i on o heir offspring. A Punne square beween he parens would look like his So ha would mean heir child would have a 25% chance of having i. Dihybrid Crosses and Excepions o Mendel 1. When creaing a dihybrid cross you are acually sudying wo rais a once, however offspring will only inheri one allele from each paren. If a paren has he following genoype, wha are he differen combinaions of ha could be passed on o heir offspring: DdGg Combinaions include: DG, Dg, dg, dg 2. If all is dominan () over shor () and Yellow (Y) is dominan over green (y), examine he following cross: Parenal Generaion: Male - Yy x Female Yy Y Y y Y y y Y y A B

4 a. Wha do he parens look like? hey are boh all and yellow b. Wha is he phenoypic raio of he offspring? 9:3:3:1 c. Wha is he genoype of he box wih an A in i? Yy d. Wha is he genoype of he box wih a B in i? YY 3. Mach he following using he word bank below: a. When organisms who are heerozygous show a blended phenoype he rai is - Incomplee Dominan b. When organisms who are heerozygous show boh forms of a rai Co-dominan c. Conrolled by muliple alleles in humans - Blood ype d. Color blindness and hemophilia are caused by genes on he X chromosome, so hey are Sex-linked e. Sex linked rais are more likely o be found in wha gender - Males f. Carriers are people who have his genoype - Heerozygous g. If someone is a carrier for a disease, he disease mus be - Recessive h. When more han one gene conrols a rai i is - Polygeneic Co-dominan Blood ype Sex linked Polygeneic Heerozygous Recessive Male Incomplee Dominan Muaions 1. Mark he following as rue or false: a. Muaions can be inheried, environmenally caused or happen during replicaion rue b. Everyone has los of hidden recessive muaions ha are no always expressed or harmful rue c. Cells have efficien sysems for correcing errors o preven muaions (hink G1 and G2 check poins in miosis) rue d. Hemophilia, cysic fibrosis and sickle cell anemia are all caused by genes ha code for defecive proeins rue Pedigrees 1. If a rai shows up equally in males and females on a pedigree ha means i is mos likely wha ype of rai? Auosomal 2. If a rai shows up more ofen in males han in females on a pedigree ha means i is mos likely wha ype of rai? Sex-linked

5 3. If everyone who shows a rai on a pedigree has a paren who also shows i, i is mos likely wha ype of rai? Dominan 4. If a child has a rai on a pedigree bu heir parens don or are only half shaded in, i mus be wha ype of rai? Recessive 5. In a pedigree where a circle of square is half shaded on ha person is a _ Carrier/heerozygous, and if i is fully shaded in ha person acually _has he disorder or rai. 6. Don forge o pracice using he pedigree on he review shee! Vocabulary Geneics Herediy Gene Muaion Meiosis his is he sudy of herediy, aka he uni we are sudying his is he passing of rais from parens o offspring his is a segmen of DNA ha carries he insrucions for a specific gene/proein A change in a gene due o damage or being copied incorrecly his is he process of creaing sex cells, i is also when alleles separae o be passed on o offspring