AP Biology 2006-2007 Beyond Mendel’s Laws of Inheritance.

Slides:



Advertisements
Similar presentations
Genetics & The Work of Mendel
Advertisements

Chapter 15: Chromosomal Basis of Inheritance
AP Biology Beyond Mendel’s Laws of Inheritance.
AP Biology Beyond Mendel’s Laws of Inheritance.
AP Biology Beyond Mendel’s Laws of Inheritance.
EXCEPTIONS TO THE RULES NON MENDELIAN INHERITANCE.
Chapter 15~ The Chromosomal Basis of Inheritance
AP Biology Chromosomal Basis of Inheritance Chapter 15.
Beyond Mendel’s Laws of Inheritance
Goal 3.03 Interpret and predict patterns of inheritance.
Bi 3a Bi 2g By Kim Foglia Beyond Mendel’s Laws of Inheritance.
Chapter 14 Draw 13 boxes on your paper Probability & genetics Calculating probability of making a specific gamete is just like calculating the probability.
Beyond Mendel’s Laws of Inheritance Extending Mendelian genetics  Mendel worked with a simple system  peas are genetically simple  most.
CHAPTER 22 Genetics & The Work of Mendel
AP Biology Beyond Mendel’s Laws of Inheritance.
AP Biology Genetics & The Work of Mendel.
Mendel, Genes, and Inheritance Chapter 12. Gregor Mendel Austrian Monk with a strong background in plant breeding and mathematics Using pea plants, found.
AP Biology Beyond Mendel’s Laws of Inheritance.
Beyond Mendel’s Laws of Inheritance
Incomplete dominance Heterozygotes show an intermediate phenotype
Beyond Mendel’s Laws of Inheritance. Extending Mendelian genetics  Mendel worked with a simple system  peas are genetically simple  most.
AP Biology Lecture #27 Exceptions to Mendelian Genetics.
Incomplete Dominance, Codominance, Multiple Alleles, and Sex-Linked Traits.
Beyond Mendel’s Laws of Inheritance
AP Biology Modified from: Kim Foglia, Explore Biology Chapter 14. Beyond Mendel’s Laws of Inheritance.
Gregor Mendel’s Discoveries Pre-Mendel  Blending Theory of Heredity –Hereditary material from each parent mixes in the offspring 2 problems Individuals.
EXCEPTIONS TO THE RULES NON MENDELIAN INHERITANCE.
AP Biology Beyond Mendel’s Laws of Inheritance.
Genetics & The Work of Mendel Modern genetics began in the mid-1800s in an abbey garden, where a monk named Gregor Mendel documented inheritance in peas.
Genetics Do Now Hand in your Karyotyping Lab if you haven’t already! Take out the Video – What are genes question sheet? Read over the questions so you.
AP Biology Beyond Mendel’s Laws of Inheritance.
Beyond Mendel’s Laws of Inheritance Extending Mendelian genetics  Mendel worked with a simple system  peas are ____________________________ simple.
Genetics & Inheritance Genetics & Inheritance The Chromosome Theory of Inheritance.
MCC BP Based on work by K. Foglia Chapter 14. Beyond Mendel’s Laws of Inheritance.
Beyond Mendel’s Laws of Inheritance
Lesson 17: Patterns of Inheritance blackwellpublishing.com
Genetics Notes #3 Beyond Mendel’s Laws Human Genetics
After Mendel Ch. 8 – 3 (con’t) Beyond Dominant And Recessive Alleles Dominant/recessive inheritance is the simplest type of gene interaction What causes.
AP Biology Beyond Mendel’s Laws of Inheritance AP Biology Extending Mendelian genetics  Mendel worked with a simple system  peas are genetically simple.
Law of Segregation alleles separate monohybrid cross Law of Independent assortment allele pairs inherited independently dihybrid cross.
AP Biology Beyond Mendel’s Laws of Inheritance.
AP Biology Beyond Mendel’s Laws of Inheritance.
CHAPTER 22 Genetics & The Work of Mendel
Complex Patterns of Inheritance Exceptions to Mendel’s rules: not simple dominant/recessive inheritance.
AP Biology Beyond Mendel’s Laws of Inheritance.
AP Biology Thanks as always to Kim Foglia Beyond Mendel’s Laws of Inheritance.
AP Biology Beyond Mendel’s Laws of Inheritance.
Beyond Mendelian Genetics Extending Mendelian genetics Mendel worked with a simple system – most traits are controlled by a single gene – each.
Non – Mendelian Genetics *Not all traits follow Mendel’s rules!
AP Biology Beyond Mendel’s Laws of Inheritance (14 continued) and 15.
AP Biology Beyond Mendel’s Laws of Inheritance.
Genetics & The Work of Mendel Gregor Mendel Modern genetics began in the mid- 1800s in an abbey garden, where a monk named Gregor Mendel documented inheritance.
What to know… Content: Difference between a chromosome, gene, allele, and locus Genotype vs phenotype Dominant vs recessive alleles Homozygous vs heterozygous.
AP Biology Beyond Mendel’s Laws of Inheritance Chapter 11.
Chapter 12.2 – 12.3 Beyond Mendel’s Laws of Inheritance.
AP Biology Beyond Mendel’s Laws of Inheritance.
Regents Biology Genetics & The Work of Mendel.
AP Biology Beyond Mendel’s Laws of Inheritance.
AP Biology Beyond Mendel’s Laws of Inheritance Extending Mendelian genetics  Mendel worked with a simple system  peas are genetically simple  most.
AP Biology Beyond Mendel’s Laws of Inheritance.
Beyond Mendel’s Laws of Inheritance
Beyond Mendel’s Laws of Inheritance
Beyond Mendel’s Laws of Inheritance
Chapter 14. Mendel & Genetics
Pedigree analysis Pedigree analysis reveals Mendelian patterns in human inheritance data mapped on a family tree = male = female = male w/ trait = female.
Complex Patterns of Inheritance
Beyond Mendel’s Laws of Inheritance
Beyond Mendel’s Laws of Inheritance
Beyond Mendel’s Laws of Inheritance
Presentation transcript:

AP Biology Beyond Mendel’s Laws of Inheritance

AP Biology Extending Mendelian genetics  Mendel worked with a simple system  peas are genetically simple  most traits are controlled by a single gene  each gene has only 2 alleles, 1 of which is completely dominant to the other  The relationship between genotype & phenotype is rarely that simple

AP Biology Incomplete dominance  Heterozygote shows an intermediate, blended phenotype  example:  RR = red flowers  WW = white flowers  RW = pink flowers  make 50% less color RR RW WW

AP Biology Incomplete dominance true-breeding red flowers true-breeding white flowers X P 100% 100% pink flowers F 1 generation (hybrids) self-pollinate 25% white F 2 generation 25% red 1:2:1 50% pink

AP Biology Incomplete dominance CRCR CWCW male / sperm CRCR CWCW female / eggs _____ ____ 1:2:1 ____ 1:2:1 % genotype % phenotype CRCRCRCR CRCWCRCW CRCWCRCW CWCWCWCW ____ C R C W x C R C W _____

AP Biology Co-dominance  2 alleles affect the phenotype equally & separately  example: ABO blood groups  3 alleles  I A, I B, i  I A & I B alleles are co-dominant to each other  both antigens are produced  both I A & I B are dominant to i allele  produces glycoprotein(carbohydrate) antigen markers on the surface of red blood cells

AP Biology Genetics of Blood type pheno- type genotype antigen on RBC antibodies in blood donation status AI A I A or I A i type A antigens on surface of RBC anti-B antibodies __ BI B I B or I B i type B antigens on surface of RBC anti-A antibodies __ ABI A I B both type A & type B antigens on surface of RBC no antibodies universal recipient Oi ii i no antigens on surface of RBC anti-A & anti-B antibodies universal donor

AP Biology Blood compatibility  Matching compatible blood groups  critical for blood transfusions  A person produces antibodies against antigens in foreign blood  wrong blood type  donor’s blood has A or B antigen that is foreign to recipient  antibodies in recipient’s blood bind to foreign molecules  cause donated blood cells to clump together  can kill the recipient Karl Landsteiner ( ) 1901 | 1930

AP Biology Blood donation clotting

AP Biology Pleiotropy  Most genes are pleiotropic  one gene affects more than one phenotypic character  wide-ranging effects due to a single gene  dwarfism (achondroplasia)  gigantism (acromegaly)

AP Biology Acromegaly: André the Giant

AP Biology Aa x aa Inheritance pattern of Achondroplasia aa A a Aa A a Aa x Aa ____ 50% dwarf:50% normal or 1:1 ____ 67% dwarf:33% normal or 2:1 ____

AP Biology Epistasis  One gene alters the expression of another gene  coat color in mice = 2 separate genes  C,c: locus determines color to be deposited pigment (C) or no pigment (c)  B,b: more pigment (black=B) or less (brown=b)  cc = albino, no matter B allele  9:3:3:1 becomes 9:3:4

AP Biology Epistasis in Labrador retrievers  2 genes: (E,e) & (B,b)  pigment (E) or no pigment (e)  pigment concentration: black (B) to brown (b) E–B–E–bbeeB–eebb

AP Biology Polygenic inheritance  Some phenotypes determined by additive effects of 2 or more genes on a single character  phenotypes on a continuum  human traits  skin color  height  weight  eye color  intelligence  behaviors

AP Biology Nature vs. nurture  Phenotype is controlled by both environment & genes Color of Hydrangea flowers is influenced by soil pH Human skin color is influenced by both genetics & environmental conditions Coat color in arctic fox influenced by heat sensitive alleles

AP Biology enzyme Skin color: Albinism Johnny & Edgar Winter albino Africans  However albinism can be inherited as a single gene trait melanin = universal brown color tyrosine melanin albinism

AP Biology OCA1 albinoBianca Knowlton

AP Biology Sex linked traits  Genes are on sex chromosomes  as opposed to autosomal chromosomes  first discovered by T.H. Morgan at Columbia U.  Drosophila breeding  good genetic subject  prolific  2 week generations  4 pairs of chromosomes  XX=female, XY=male 1910 | 1933

AP Biology autosomal chromosomes sex chromosomes Classes of chromosomes

AP Biology F 2 generation 100% red-eye female 50% red-eye male 50% white eye male Discovery of sex linkage P X F 1 generation (hybrids) 100% red eye offspring true-breeding white-eye male true-breeding red-eye female

AP Biology RRrr What’s up with Morgan’s flies? x rr R R Rr 100% red eyes Rr x Rr R r RR Rrrr Rr 3 red : 1 white Doesn’t work this way!

AP Biology  In humans & other mammals, there are 2 sex chromosomes: X & Y  2 X chromosomes  develop as a female: XX  gene redundancy, like autosomal chromosomes  an X & Y chromosome  develop as a male: XY  no redundancy Genetics of Sex 50% female : 50% male

AP Biology _____ What’s up with Morgan’s flies? x ____ 100% red eyes ____ _____ x ____ _____ 100% red females 50% red males; 50% white males

AP Biology Genes on sex chromosomes  Y chromosome  few genes other than SRY  sex-determining region  master regulator for maleness  turns on genes for production of male hormones  many effects = pleiotropy!  X chromosome  other traits beyond sex determination  mutations:  hemophilia  Duchenne muscular dystrophy  color-blindness

AP Biology  Sex-linked  usually means “X-linked”  more than 60 diseases traced to genes on X chromosome Human X chromosome

AP Biology Map of Human Y chromosome? < 30 genes on Y chromosome Sex-determining Region Y ( SRY ) Channeling Flipping ( FLP ) Catching & Throwing ( BLZ-1) Self confidence ( BLZ-2) note: not linked to ability gene Devotion to sports ( BUD-E) Addiction to death & destruction movies ( SAW-2) Scratching ( ITCH-E) Spitting ( P2E) linked Inability to express affection over phone ( ME-2) Selective hearing loss ( HUH) Total lack of recall for dates ( OOPS) Air guitar ( RIF)

AP Biology Sex-linked traits summary  X-linked  follow the X chromosomes  males get their X from their mother  trait is never passed from father to son  Y-linked  very few genes / traits  trait is only passed from father to son  females cannot inherit trait

AP Biology

Hemophilia Hh x HH sex-linked recessive ___ male / sperm ___ female / eggs carrierdisease

AP Biology X-inactivation  Female mammals inherit 2 X chromosomes  one X becomes inactivated during embryonic development  condenses into compact object = Barr body  which X becomes Barr body is random  patchwork trait = “mosaic” XHXhXHXh XHXHXhXh

AP Biology X-inactivation & tortoise shell cat  2 different cell lines in cat

AP Biology Male pattern baldness  Sex influenced trait  autosomal trait influenced by sex hormones  age effect as well = onset after 30 years old  dominant in males & recessive in females  B_ = bald in males; bb = bald in females

AP Biology Epistasis in grain color 9/16 purple 7/16 white F 1 generation All purple (AaBb) X Eggs White (aaBB) White (AAbb) F 2 generation A = enzyme 1 + B = enzyme 2  purple color (anthocyanin) AB AbaBab Ab aB ab AABB AABb AaBB AaBb AABb AAbb AaBb Aabb AaBB AaBb aaBB aaBb AaBb Aabb aaBb aabb Sperm 9:7 9:3:3:1