Calendar
Contact Teacher
Labs:
   nothing
   nothing
   nothing
Links
Notes:
   Animal Body
   Arthropods
   Biochem
   Cell Cycle
   Cell Interactions
   Cell Structure
   Circulation Respiration
   Communities
   Digestion
   DNA
   Ecosystems
   Energy
   Evolution Evidence
   Future of Biosphere
   Genetic Engineering
   Gene Function
   Genetics
   Hormones
   Human Evolution
   Immunity
   Species Interaction
   Kidneys
   Locomotion
   Membranes
   Mollusks
   Mutation
   Nervous
   Non-Coelmic
   Photosynthesis
   Plant Physiology
   Population Genetics
   Population Dynamics
   Cellular Respiration
   Sensory
   Speciation
   Taxonomy
   Vertebrates
   Vertebrate Org
Vocabulary:
   1,2,3,4,5,6,7,8,9,10,
   11,12,13,14,15,
   16,17,18,19,20,
   21,22,23,24,25,
   26,27,28,29,30,
   31,32,33,34,35,
   36,37,38,39,40,
   41,42,43,44,45,
   46,47,48,49,50,
   51,52,53,54

Genetics

I. Early Ideas
   A. Blending
   B. Any trait you had, your child would have (Darwin thought)
   C. Sex between species (horse & human)
   D. Josef Koelreuter
      1. First to successfully hybridize plants
      2. Important discovery
         a) Traits were capable of being masked in one generation and reappear in the next
   E. T.   A. Knight
      1. Crossed true-breeding peas, purple & white
      2. F₁ had purple
      3. F₂ had both
      4. Purple dominant
   F. Genotype – actual genes
   G. Phenotype – physical appearance
   H. Alleles – two potential genes
I. Homozygous – same ~> PURE
   J. Heterozygous – different ~> HYBRID
   K. Locus – site on chromosome where gene is located
   L. Dominant
   M. Recessive
   N. P₁ – Parent Generation
   O. F₁ – First Filia
II. Mendel
   A. Def: Study of Patterns of Inheritance
   B. Background
      1. Studied peas (grow fast, “complete dominance”)
      2. Each parent contributes half of the trait
      3. “Material” which determines traits
      4. Proposed 3 Laws of Inheritance
   C. 3 Laws
      1. Law of Dominance
         a) When two organisms are pure for traits are crossed, the offspring will be 100% of the dominant trait.
         b) Ex. Pure Red x Pure White

	R	R	R = Red	r = white
r	Rr	Rr
r	Rr	Rr	G	P
			100% Hybrid	100% Red

      2. Law of Segragation
         a) When two F1 progeny are crossed, the recessive trait will reappear
         b) Ex. Hybrid x Hybrid

			R = Red	r = white
	R	r
R	RR	Rr	G	P
r	Rr	rr	25% homozygous (dom)	75% Red
			50% hybrid	25% White
			25% homozygous (rec)	(3:1)

      3. Independent Assortment
         a) Traits are inherited independent of each other. There is no linkage
         b) To Prove:
            (1) Cross two pure plants for two traits

R – Purple		RRGG x rrgg
r - White
G - Round		RrGg <~100% dihybrid
g - Wrinkled

F₁

	RR	Rr	Rr	rr
GG	RRGG	RrGG	RrGG	rrGG	9 – Purple & Round
Gg	RRGg	RrGg	RrGg	rrGg	3 – Purple & Wrinkled
Gg	RRGg	RrGg	RrGg	rrGg	3 – White & Round
gg	RRgg	Rrgg	Rrgg	rrgg	1 - White & Wrinkled

         c) All genes on different chromosomes are assorted independently
         d) Genes on same chromosome can be linked in function (expressio         n) & inheritance
III. Genotype to Phenotype
   A. Complex Genetic Patterns
      1. Multiple alleles: more than two alleles
      2. Gene Interaction
      3. Epistasis
      4. Continuous variation
      5. Pleiotropy
      6. Incomplete Dominance
      7. Environmental effects
   B. Modified Mendelian Ratios
      1. Difficult to determine phenotype
      2. Example corn seed
IV. Chromosomes
   A. Sutton
   B. Morgan – Fruit flies (8 chromosomes; reproduce rapidly)
      1. Proof of Chromosomal Theory of Inheritance
         a) Discovery of mutant
         b) Crossed w/ wild type, red-eyed C
         c) All red eyes
         d) F₁
            (1) 3:1 ratio red to white
            (2) All recessive white were males
         e) Test Cross F₁
            (1) 1:1:1:1 ratio
      2. Eye Color Gene located on Sex Chromosome
         a) X and Y
         b) XX female XY male
         c) Eye color on X
         d) \ sex linked on X
V. Crossing Over
   A. When homologous chromosomes exchange genetic information
   B. Genetic Map
      1. A measure of the distance between genes
      2. You arrive at it by measuring the frequency which crossing over occurs
      3. Lower frequency ~> closer together
      4. Higher frequency ~> farther apart
      5. So close, called “linked”
   C. Centimorgan
      1. Unit of measure or map unit
      2. Distance within which crossing over event is expected to occur in any 1% of gametes
      3. Formula: % of crossing over / 2
      4. In order to monitor crossing over percentages, you must look at 3 or more genes (synthetic)
   D. “+” is a wild type ~> most common allele
   E. First 22 are autosomal
   F. 23 is sex chromosome
   G. Male is XY
   H. Female is XX
I. Y is more condensed; highly ~> “unique maleness”
   J. One X in female is dormant; Barr Body (inactivated X)
   K. Individual cells decide which to turn off
   L. Nondistjunction – chromosomes don’t pull apart
   M. Trisomic – extra
   N. Monosomic – one less
   O. Down Syndrome – extra 21
   P. Nondistjunction of Sex Chromsomes       1. XX w/ X ~> female, 1 normal 2 Barr Bodies & sterile
      2. XX w/ Y ~> male w/ female parts, sterile, retarded (Kleinfelters: 1 in 500)
      3. Y w/ O ~> DIES!
      4. X w/ O ~> female, that is sterile, short, weeped neck, immature sex organs, low mental ability (Turners: 1 in 5,000)
VI. Multiple Alleles
   A. Most genes possess for than 2 possibilities
   B. ABO Blood Group
      1. 3 alleles ~> A, B, none
      2. 4 phenotypes (A, B, AB, O)
         a) A ~> AA or AO <~ 3%
         b) B ~> BB or BO <~ 3%
         c) AB ~> AB <~ 1%
         d) O ~> OO <~ 94%

Type	Receive From	Donate to
A	A, O	A, AB
B	B, O	B, AB
AB	AB, A, B, O	AB	<~ Universal Recipient
O	O	AB, A, B, O	<~ Universal Donor

      3. Rh factor (Rhesus)
         a) 7 different factors on surface of blood cell
         b) Any one of them you are +
         c) None of the seven, you are –
         d) If you are a mother that is – w/ child that is +, she develops + antigens; second child is +, then the mother’s immune system fights it off!!

Genetics

Layout by J.T. Poirier © 2001