Drill #15Quote: Along with success comes a reputation for wisdom.

Euripides

Agenda:

Exceptions to Mendelian Genetics

Review Session

Warm-up:

Name 2 of your favorite Thanksgiving foods and the corresponding macromolecule category.

Mendelian Exceptions

Chapter 11

Section 3

Mendel’s Principles Revisited

Inheritance of biological _____________ is determined by individual units known as ______.

During sexual reproduction, genes are passed from parents to _________.

Two or more forms of the gene for a single _____ exist, some forms of the gene may be _________ and others may be recessive.

characteristics

offspring

genes

traitdominant

Mendel’s Principles Revisited

Organisms typically have ____copies of each gene, (one from each _______)

An organism’s _____ 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)

independently

parenttwo

gametes

genes

pair

Independent Assortment in Peas

__ Round yellow__ Round green__ Wrinkled yellow__ Wrinkled green

9331

Incomplete Dominance

In incomplete dominance, neither allele is __________ so there is a blending of ______ when two different alleles for the same trait occur together.

Colors blend together (______________

individuals = 3rd phenotype)

dominanttraits

heterozygous

red whitepink

Incomplete Dominance

In Four O’ Clocks, if you cross a red _____(which is always pure) with a white _____ (that is also always pure) , you get apink _____ (whichis always hybrid /heterozygous

RRWW

RW

RWRW

RW RW

Incomplete Dominance

In another flower, if red ____ and blue ____ flowers are crossed, they produce a 3rd purple ____ flower

What would be the genotype ratio and phenotype ratio if you crossed two purple flowers?

RRBB

RB

Incomplete Dominance Cross of two purple flowers

____ X ____ What are gamete possibilities? genotype ratio

1RR : 2RB : 1BB phenotype ratio

1red : 2 purple : 1 blue Can you have a

heterozygous red orhybrid blue flower? ___

B

R

R B

BBRB

RR RBred purple

purple blue

RB RB

no

Codominance Both _______ 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 _____.

alleles

redwhite

roan

Codominance

These 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…

W

W

R W

WWRW

RW WW

phenotype

roan

roan

white

white

Codominance Andalusian chickens also show this

pattern of inheritance. If you cross a black (BB) chicken With a white (WW) chicken You get black+white speckled (BW) chicken

Multiple Alleles

In 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.

two

twotwo

trait

Multiple Alleles

Blood 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

four

three

Phenotype Genotype

A AA or AO

B BB or BO

AB AB only

O OO only

Multiple Alleles Examples of Blood type crosses

Phenotype(Blood Type

Multiple Alleles

Genotype

Blood Groups

Antigen on Red Blood Cell

Safe Transfusions

To From

Multiple Alleles

The example of _______ hair color, which has at least four different alleles, (on text pg 273) is seen in these different Rex rabbits.

rabbit

Polygenic Traits

Traits controlled by two or more genes Show a wide range of phenotypes The phenotype

is produced by the interaction of more than ________ of genes.

1 pair

Polygenic Traits These are called ___________ traits,

which means “having _______ genes”. In humans, _____ color, _____ color,

polygenicmany

skineye

Polygenic Traits These are called ___________ traits,

which means “having _______ genes”. In humans, _____ color, _____ color, and _____ color

polygenicmany

skineye

hair

Polygenic Traits These are called ___________ traits,

which means “having _______ genes”. In humans, _____ color, _____ color, and _____ color are just a few of

the many traits __________ by many genes.

polygenicmany

skin

controlled

eye

hair