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10.3 Variations in Inheritance, Its MOOOOOving!!!Mendels Principles Revisited Organisms typically have ____copies of each gene, (one from each _______)An organisms _____ of genes (2 alleles) are segregated from each other when ________ are formed.Alleles for different ______ usually segregate _____________ of one another. (through meiosis)(Law of Independent Assortment)independentlyparenttwogametesgenespair2Independent Assortment in Peas

__ Round yellow__ Round green__ Wrinkled yellow__ Wrinkled green

93313Chapter 10.3 - There are many variations of inheritance patterns

Intermediate Inheritance - Inheritance in which heterozygotes have phenotypes between the phenotypes of 2 homozygotes. Example - Red & White = Pink(also called Inbetween or Incomplete Dominance)

Intermediate Inheritance = Incomplete DominanceCross of two purple flowers____ X ____What are gamete possibilities?genotype ratio 1RR : 2RB : 1BBphenotype ratio 1red : 2 purple : 1 blueCan you have a heterozygous red or blue flower? ___BRRBBBRBRRRBredpurplepurpleblueRBRBno5http://www.gwu.edu/~darwin/BiSc150/One/rose.GIFIntermediate Inheritance

ChickensC = Trait-ColorCB = BlackCW = White

What do we get if we cross - Black xWhite CBCBCWCW

CBCBCWCBCWCBCW

CWCBCW

CBCW

CBCW

Remember, the 1st generation of babies are called the F1 generation.

Neither black nor white are dominant. No capital or lower case letters are usedParent Phenotypes can reappear in the F2 generation Now, well cross 2 of the babies CBCW X CBCWCBCWCBCBCBCBCWCWCBCWCWCW25% - CBCB BLACK

50% - CB CW BLUE

25 % - CWCW WHITE

CodominanceBoth _______ contribute to the phenotype of the organism by showing up simultaneously (at the same time) in heterozygous

individuals. In cattle and horses, if you cross a pure ____ (RR) with a pure ______ (WW), you get (RW) which produces the color _____.

allelesredwhiteroan9

RRWWRWAnother Example of codominance Cow color

CodominanceThese cattle or horses actually have both red and white hairs intermixed, or are spotted. Roan is a third ___________.If you cross a roan with a white

WWRWWWRWRWWW

phenotyperoanroanwhitewhite11http://www.ccs.k12.in.us/chsteachers/Amayhew/Biology%20Notes/beyond%20dominance%20notes_files/image004.jpgMultiple AllelesIn this pattern of inheritance, the genes have more than _____ alleles controlling them and are therefore said to have multiple alleles. No individual has more than _____ alleles, but there are more than _____ possible alleles in a population, so a ______ will be expressed in more than two forms. twotwotwotrait12Multiple AllelesBlood type in humans is an example of this inheritance pattern. The ______ different blood groups: A, B, O, and AB Are produced by ______ different alleles: A, B, and O

fourthreePhenotypeGenotypeAAA or AOBBB or BOABAB onlyOOO only

13What is the universal donor?OWhat is the universal receiver? AB

14Multiple AllelesThe example of _______ hair color, which has at least four different alleles, is seen in these different Rex rabbits.rabbit

15Polygenic TraitsTraits controlled by two or more genesShow a wide range of phenotypesThe phenotype is produced by the interaction of more than ________ of genes.

1 pair16http://anthro.palomar.edu/adapt/images/skin_color_range.jpghttp://www.sciam.com/media/inline/0002E7CA-F27B-13A1-AFAA83414B7FFE9F_1.gif

Polygenic Inheritance - Combined effect of 2 or more genes on a single characteristic. (not either-ors)Example -Skin Color (Yes simplified)A, B, C contributes on unit of colorThe recessive a, b, c do not contribute any unit of colorHuman examples: skin, eye and hair color

When multiple genes affect a character the variation in phenotype is great.

Meaning - The more genes there are, the more possible combinations.

Think about it like this - the more $$$$ you have, the more possible ways there are to spend it!Potential combinations of alleles for a character increase with the number of genes that affect one character.

Importance of environment

Sometimes, phenotypes can depend on the environment.

Example #1 - Trees & leavesYear to year, the leaves change size, color and shape. What affects this?Temperature & Sunlight!

Others.. MUWAHAHASiamese cats and Himalayan rabbits Himalayan rabbits normally are white as melanin is not produced at temperatures above 35 C.If one shaves hair from back and places ice pack on the shaven skin, black hair is produced. The ears, tail, and feet are normally black because they have less hair and are cooler.