Chapter 9 Lab Bio Chapter 12 Honors Bio

 Brainstorm : - define genetics - define heredity  Anticipatory Set:  How important is it to be able to find your own answers to questions you may face?  Does education and learning end with your high school or college years?  How do you plan to develop the skills to become a life long learner?

 The study of how characteristics are transmitted from parent to offspring

 The transmission of characteristics from parent to offspring

 Chromosome: structure within nucleus, made of DNA  Gene: unit of heredity found in DNA molecule (words)  Allele: symbols (letter) used to represent genes ex: T=tall, t=short  Dominant: trait/characteristic that are expressed – represented with capital letter  Recessive: trait/characteristic that may not be expressed (always lower case) ex: t=short

 Homozygous/pure: both alleles are alike ex: TT or tt  Heterozygous/hybrid: alleles differ ex: Tt  Genotype: genetic make up ex: (pure homozygous) tall, hybrid (hetero.) tall  Phenotype: what you see (physical appearance) ex: tall, short  Cross: symbolic of reproduction ____ X _____  P: parent generation  F1: first generation

 A GENE is the segment of DNA on a chromosome that controls a particular trait.  Chromosomes are in pairs i.e.  Genes occur in pairs (each of several alternative forms of a gene is called an ALLELE  MENDEL’S FACTORS ARE NOW KNOW AS ALLELES!!!!!!

 CAPITAL = Dominant alleles  Lower case = recessive alleles  Example: P = purple color (dom.)  p = white color (rec.)  When gametes combine in fertilization offspring receive ONE ALLELE for a given trait from EACH PARENT!

 Helps us predict the likely outcome of offspring!!  1. genotype: genetic make-up, consists of alleles  Ex: P=purple, p=white  Pp = purple  PP = purple  White = pp

 2. Phenotype = appearance of an offspring (what you see)  Ex: purple flowers, white flowers, hair color

 3. Homozygous = when both alleles of a pair are alike  Ex: tt, TT, PP, pp  Homozygouse recessive = pp  Homozygouse dominant = PP

 4. Heterozygous = two alleles in a pair are different  Ex: Pp or Tt

 Do you think that we could make as many discoveries in science if we didn’t use animals? Explain…..

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 Austrian Monk  Studied garden pea plants (Pisum sativum)  1842 he entered the monastery in Austria  1851 enetered Univ. of Vienna to study science and mathematics (statistics)

 Observed 7 characteristics each in 2 contrasting traits:  Long  short stems  Axial  terminal (flower position)  Green  yellow (pod color)  Inflated  constricted (pod appearance)  Smooth  wrinkled (seed texture)  Yellow  green (seed color)  Purple  white (flower color)

 He controlled how pea plants were POLLINATED!!!  SELF POLLINATION=pollen is transferred from anthers (male) of a flower to stigma (female) of same flower or flower on the same plant  CROSS POLLINATION=involves flowers of 2 separate plants

 1. remove anthers from a flower  2. manually transfer the anther of a flower on one plant to stigma of a flower on another plant

 P 1 (cross) pure Purple x pure White  Law of Dominance  F 1 ALL came out PURPLE  F 1 (cross) Purple x Purple  Law of Segregation  F 2 ¾ PURPLE, ¼ WHITE

 Mendel hypothesized that the trait appearing in the F 1 generation was controlled by a DOMINANT FACTOR (allele) because it masked, or dominated, the other factor for a specific characteristic.  RECESSIVE is the trait that did not appear in the F 1 generation but reappeared in the F 2 generation.

 A pair of factors (alleles) is segregated (or separated) during the formation of gametes  Each reproductive cell (gamete) receives only one factor (allele) of each pair.  Crossed two heterozygous purple plants!

 Is the purple plant homozygous or heterozygous ?  Perform a test cross!  Always! Cross the unknown with a homozygous recessive Test Cross

g g GG GG gg gg P F1F1 Key: G=green g= yellow Key: G=green g= yellow Phenotype: 100% green Genotype: 100% heterozygous ? x gg

P F1F1 Key: G=green g= yellow Key: G=green g= yellow Phenotype: 50% green 50% yellow Genotype:

 Neither allele is dominant  In some cases, an intermediate phenotype is shown

 In snapdragons, flower color can be red, pink, or white. The heterozygous condition results in pink flowers rrRr RR

Key: R= Red r= White Key: R= Red r= White F1 Phenotype: 100% pink F1 Genotype: 100% heterozygous Rr F1 Phenotype: 100% pink F1 Genotype: 100% heterozygous Rr

Key: R= Red r= White Key: R= Red r= White Phenotype: 1:2:1 25% Red 25% White 50% Pink Genotype: 1:2:1 25% homozygous RR 25% homozygous rr 50% heterozygous Rr Phenotype: 1:2:1 25% Red 25% White 50% Pink Genotype: 1:2:1 25% homozygous RR 25% homozygous rr 50% heterozygous Rr

 Both alleles are expressed equally  Neither allele is more dominant than the other Erminette chickens Roan Cows

 P generation  Black chicken X White chicken  F1 generation = erminette (checkered patterned) Key: B =Black B 1 = White Key: B =Black B 1 = White BB B1B1 B1B1 B BB BB1B1 B1B1 B1B1 B1B1 Phenotype: 4:0 or 1:0 100% erminette Genotype: 4:0 or 1:0 100% heterozygous Phenotype: 4:0 or 1:0 100% erminette Genotype: 4:0 or 1:0 100% heterozygous

B B B W B BWBW BBB B BWBW BWBW BWBW BWBW Key: B= Black W= White Key: B= Black W= White Key: B B =Black B W = White Key: B B =Black B W = White B1B1 B1B1 B2B2 B2B2 B1B1 B1B1 B1B1 B1B1 B2B2 B2B2 B2B2 B2B2 Key: B 1 =Black B 2 = White Key: B 1 =Black B 2 = White

 1. What does recombination mean?  2. Do you know of any traits that seems to be inherited together?  Ex: red hair and fair skin……

 Does anyone here look “nothing” like their parents?  If not do you know someone who looks nothing like their family members?  Can we explain this genetically?

 Traits are inherited independently of each other unless they are linked.  Random Assortment  Genetically Unique

 Independent Assortment is the random assortment of chromosomes during the production of gametes, the result are genetically unique individual gametes.

 He also crossed plants with 2 different characteristics  Ex: flower color & seed color  FACTORS FOR DIFFERENT CHARACTERISTICS ARE DISTRIBUTED TO GAMETES INDEPENDENTLY.  Ex: Pure tall yellow x pure short green  TTYY x ttyy

Xy = XX= female male Female karyotype Male karyotype

 Nondisjunction: failure of chromosomes to separate during meiosis 1 or 2  Results in an extra chromosome or a missing chromosome  hill.com/olcweb/cgi/pluginpop.cgi?it=swf::550::400::/sites/dl/ free/ /383925/Chapter11_NGS_VisualizingNondisju nction_10_10_06.swf::Visualizing%20Nondisjunction hill.com/olcweb/cgi/pluginpop.cgi?it=swf::550::400::/sites/dl/ free/ /383925/Chapter11_NGS_VisualizingNondisju nction_10_10_06.swf::Visualizing%20Nondisjunction  XO- Turner Syndrome  XXX- Trisomy X  XXY- Klinefelter Syndrome  XYY- Jacob Syndrome  Very often, symptoms are slight due to X-inactivation and the small amount of genes found on the Y chromosome

SEX LINKED TRAITS

X-LINKED GENES: Genes carried on the X chromosome Hemophilia Color blindness Baldness Muscular Dystrophy

Mother Without hemophilia = X X With hemophilia = X X Father Without hemophilia = X y With hemophilia = X y H H h h CARRIER H h

How common is your blood type? 46.1% 38.8% 11.1% 3.9%

 Human blood type is determined by co-dominant alleles  Antigens-proteins-exist on the surface of all of your red blood cells. Blood types For simplicity IAIA A IBIB B iO

 Found in the plasma  Specific to a single kind of antigen  Attack and kill that specific kind of antigen

There are 3 alleles for blood type: A, B, O Since we have 2 genes: 6 possible combinations Blood Types AA or AO = Type A BB or BO = Type B OO = Type O AB = Type AB

RBC= Red Blood Cell = antibody RBC= Red Blood Cell = antibody Antibody B- protects the body by attacking foreign B antigen blood

Blood Transfusions Blood transfusions – used to replace blood lost during surgery or a serious injury or if the body can't make blood properly because of an illness. Who can give you blood? TYPE O -Universal Donors can give blood to any blood type No antigens present on RBC TYPE AB- Universal Recipients can receive any blood type No antibodies present in plasma Universal Donor Universal Recipient

 Rhesus monkeys –contain certain similarities with humans  A blood protein was discovered and present in the blood of some people  The presence of the protein, or lack of it, is referred to as the Rh (for Rhesus) factor.  Rh positive (Rh+) - contain the protein  Rh negative (Rh-)- NOT contain the protein A+ A- B+ B- AB+ AB- O+ O- Rh factorPossible genotypes Rh + Rh + /Rh + Rh + /Rh - Rh - Rh - /Rh -

Have you ever seen a family tree… do you have one?? Graphic representation of family inheritance. Pedigree of Queen Victoria

 Shows a pattern of inheritance in a family for a specific trait (phenotype)  Genotypes can usually be determined

 Track the occurrence of diseases such as:  Huntington’s – simple dominant – lethal allele – causes breakdown of the brain  Cystic fibrosis – 1/2500 – mucus accumulates (white North Amer.)  Tay-Sachs disease – lipids accumulate in CNS (Jewish)  Phenylketonuria – missing enzyme causes problems in CNS (Nordic/Swedish)

generations are numbered with Roman Numerals oldest offspring are on the left

 Autosomal dominant: –Examples: Polydactyly –Huntington’s disease The disease is passed from the father (II-3) to the son (III-5), this never happens with X-linked traits. The disease occurs in three consecutive generations, this is rare with recessive traits. Males and females are affected, with roughly the same probability.

 Autosomal recessive –Cystic fibrosis –Tay-Sach’s disease Males and females are equally likely to be affected. The trait is characteristically found in siblings, not parents of affected or the offspring of affected. Parents of affected children may be related. The rarer the trait in the general population, the more likely a consanguineous mating is involved.

 Sex-linked recessive conditions –Examples: –Color-blindness –Duchenne Muscular Dystrophy The disease is never passed from father to son. Males are much more likely to be affected than females. All affected males in a family are related through their mothers. Trait or disease is typically passed from an affected grandfather, through his carrier daughters, to half of his grandsons.

X-linked recessive Autosomal dominant Autosomal recessive X-linked recessive Autosomal dominant Autosomal recessive

X-linked recessive Autosomal dominant Autosomal recessive X-linked recessive Autosomal dominant Autosomal recessive

X-linked recessive Autosomal dominant Autosomal recessive X-linked recessive Autosomal dominant Autosomal recessive

 Law of Dominance  Law of Segregation  Test Cross  MENDEL’S RULES DO NOT APPLY TO :  Incomplete dominance  Multiple alleles  Codominmanmce  Polygenic inheritance  Pleiotyropy  Environmental influence

 Law of dominance  Law of segregation  Test cross  Incomplete dominance  Codominance  Independent assortment  Sex determination  Sex linkage  Multiple alleles