CHAPTER 10.1CHAPTER 10.1

GENETICS DEVELOPED GENETICS DEVELOPED FROM CURIOSITY ABOUT FROM CURIOSITY ABOUT

INHERITANCEINHERITANCE

THE BLENDING THE BLENDING HYPOTHESIS OF HYPOTHESIS OF INHERITANCEINHERITANCE

Trait-Trait- a variation of a particular gene a variation of a particular gene

TONGUE ROLLINGTONGUE ROLLING

HITCHHIKERS THUMBHITCHHIKERS THUMB

BENT PINKYBENT PINKY

EARLOBESEARLOBES

WIDOWWIDOW’’S PEAKS PEAK

DIMPLESDIMPLES

MID-DIGIT HAIRMID-DIGIT HAIR

THE BLENDING THE BLENDING HYPOTHESIS OF HYPOTHESIS OF INHERITANCEINHERITANCE

Blending Hypothesis-Blending Hypothesis- early 1800 early 1800’’s, s, offspring would appear as a blending offspring would appear as a blending of parental traitsof parental traits

Example: Purple flower X White Example: Purple flower X White Flower = Pink FlowerFlower = Pink Flower

ACTUALITY: Purple flowerACTUALITY: Purple flower DISPROVEDDISPROVED

MENDELMENDEL’’S PLANT S PLANT BREEDING EXPERIMENTSBREEDING EXPERIMENTS

Gregor Mendel-Gregor Mendel- Austrian monk, gave Austrian monk, gave rise to genetics, studied pea plantsrise to genetics, studied pea plants

GREGOR MENDELGREGOR MENDEL

PEA PLANT PEA PLANT CHARACTERISTICSCHARACTERISTICS

MENDELMENDEL’’S PLANT S PLANT BREEDING EXPERIMENTSBREEDING EXPERIMENTS

Genetics-Genetics- the study of heredity the study of heredity True Breed-True Breed- when a plant is crossed when a plant is crossed

with itself, it ALWAYS produces with itself, it ALWAYS produces identical offspringidentical offspring

Cross-fertilization-Cross-fertilization- sperm from the sperm from the pollen of one flower fertilizes the pollen of one flower fertilizes the eggs in the flower of a different eggs in the flower of a different plantplant

Class WorkClass Work

1.1. Explain how Mendel's particulate Explain how Mendel's particulate hypothesis is different from the hypothesis is different from the blending hypothesis of inheritance.blending hypothesis of inheritance.2.2. What is the difference between self- What is the difference between self-fertilization and cross-fertilization?fertilization and cross-fertilization?3.3. Describe a pattern of inheritance Describe a pattern of inheritance that the blending hypothesis fails to that the blending hypothesis fails to explain.explain.

CHAPTER 10.2CHAPTER 10.2

MENDEL DISCOVERED MENDEL DISCOVERED THAT INHERITANCE THAT INHERITANCE FOLLOWS RULES OF FOLLOWS RULES OF

CHANCECHANCE

MENDELMENDEL’’S PRINCIPLE S PRINCIPLE OF SEGREGATIONOF SEGREGATION Hybrid-Hybrid- an individual with two different an individual with two different

allelesalleles HhHh

Pure Breed (true breed)-Pure Breed (true breed)- an individual an individual with two of the same alleleswith two of the same alleles hh or HHhh or HH

Allele- alternate forms of a gene (letters)Allele- alternate forms of a gene (letters)

MENDELMENDEL’’S PRINCIPLE OF S PRINCIPLE OF SEGREGATIONSEGREGATION

Homozygous-Homozygous- when two alleles are the when two alleles are the samesame HH or hhHH or hh

Heterozygous-Heterozygous- when two alleles are when two alleles are differentdifferent HhHh

Dominant-Dominant- apparent, capital letter (H) apparent, capital letter (H) Recessive-Recessive- masked, lower case letter (h) masked, lower case letter (h)

MENDELMENDEL’’S PRINCIPLE OF S PRINCIPLE OF SEGREGATIONSEGREGATION

Principle of Segregation-Principle of Segregation- when two when two alleles separate during the formation alleles separate during the formation of gametesof gametes

Punnett Square-Punnett Square- a tool to predict the a tool to predict the possible outcomespossible outcomes

MENDELMENDEL’’S PRINCIPLE OF S PRINCIPLE OF SEGREGATIONSEGREGATION

Test Cross-Test Cross- breed breed a homozygous a homozygous recessive recessive individual with a individual with a dominant dominant phenotypephenotype

MENDELMENDEL’’S PRINCIPLE OF S PRINCIPLE OF SEGREGATIONSEGREGATION

Phenotype-Phenotype- an observable trait an observable trait Genotype-Genotype- genetic makeup, genetic makeup,

combination of allelescombination of alleles

MENDELMENDEL’’S PRINCIPLE OF S PRINCIPLE OF INDEPENDENT INDEPENDENT ASSORTMENTASSORTMENT

Dihybrid Cross-Dihybrid Cross- cross organisms cross organisms differing in two characteristics, differing in two characteristics, proves independent assortmentproves independent assortment

Predict the colors of the Predict the colors of the offspring of 2 true-breeding offspring of 2 true-breeding Mirabalis plants, one white, Mirabalis plants, one white, and one red.and one red.

MENDELMENDEL’’S PRINCIPLE OF S PRINCIPLE OF INDEPENDENT INDEPENDENT ASSORTMENTASSORTMENT

Principle of Independent Principle of Independent Assortment-Assortment- alleles for genes are alleles for genes are sorted independently of one anothersorted independently of one another

Class WorkClass Work 1.1. What are the two possible gametes produced What are the two possible gametes produced

by a plant that has the genotype by a plant that has the genotype AaAa? Give the ? Give the probability of each type of gamete.probability of each type of gamete.2.2. Use a Punnett square to predict the genotypes Use a Punnett square to predict the genotypes produced if the plant in Question 1 is self-produced if the plant in Question 1 is self-fertilized. Calculate the probability of each fertilized. Calculate the probability of each outcome.outcome.3.3. List all the possible genotypes of a pea plant List all the possible genotypes of a pea plant with purple flowers and round seeds.with purple flowers and round seeds.4.4. List the four possible allele combinations in the List the four possible allele combinations in the gametes of a plant with genotype gametes of a plant with genotype PpWw.PpWw.

CHAPTER CHAPTER 10.3/10.4/10.510.3/10.4/10.5

THERE ARE MANY VARIATIONS OF THERE ARE MANY VARIATIONS OF INHERITANCE PATTERNS/MEIOSIS INHERITANCE PATTERNS/MEIOSIS

EXPLAINS MENDELEXPLAINS MENDEL’’S PRINCIPLE/SEX-S PRINCIPLE/SEX-LINKED TRAITS HAVE UNIQUE LINKED TRAITS HAVE UNIQUE

INHERITANCE PATTERNSINHERITANCE PATTERNS

INTERMEDIATE INTERMEDIATE INHERITANCEINHERITANCE

Intermediate Inheritance-Intermediate Inheritance- when a when a heterozygote has a phenotype heterozygote has a phenotype between both homozygous parentsbetween both homozygous parents

Also known as incompelte Also known as incompelte dominancedominance

MULTIPLE ALLELESMULTIPLE ALLELES

When several alleles exist in a When several alleles exist in a populationpopulation

Example: BloodExample: Blood

MULTIPLE ALLELESMULTIPLE ALLELES

Codominance-Codominance- when a heterozygote when a heterozygote expresses both traitsexpresses both traits IIaaIIbb

How is this different than How is this different than intermediate inheritance?intermediate inheritance?

POLYGENIC POLYGENIC INHERITANCEINHERITANCE

When two or more genes affect a When two or more genes affect a single charactersingle character

IMPORTANCE OF IMPORTANCE OF ENVIRONMENTENVIRONMENT

Leaves vary in size, shape, and greenness Leaves vary in size, shape, and greenness from year to year depending on exposure from year to year depending on exposure to wind and sunlightto wind and sunlight

Nutrition/Exercise influence on height, Nutrition/Exercise influence on height, body build, and skin colorbody build, and skin color

Temperature and furTemperature and fur Siamese CatsSiamese Cats

CHROMOSOME THEORY CHROMOSOME THEORY OF INHERITANCEOF INHERITANCE

Chromosome Theory of Inheritance-Chromosome Theory of Inheritance- genes are located on chromosomes, genes are located on chromosomes, inheritance patterns are based on inheritance patterns are based on fertilization and meiosisfertilization and meiosis

CHROMOSOME THEORY CHROMOSOME THEORY OF INHERITANCEOF INHERITANCE

Gene Locus-Gene Locus- the location of a trait on the location of a trait on a chromosomea chromosome

GENETIC LINKAGE AND GENETIC LINKAGE AND CROSSING OVERCROSSING OVER

Genetic Linkage-Genetic Linkage- the tendency for the tendency for alleles to be inherited togetheralleles to be inherited together

SEX-LINKED GENESSEX-LINKED GENES

Sex-linked gene-Sex-linked gene- genes located on a genes located on a sex chromosomesex chromosome

In humans sex linked genes are on In humans sex linked genes are on the X chromosome (most of the time)the X chromosome (most of the time)

Why do you think?Why do you think? Men: XYMen: XY Women: XXWomen: XX

Sex-Sex-linked linked

InheritaInheritancence

Why are some diseases more common in men than women?

Ex. Color blind 8 % of males,8 % of males, but only 0.5% femalesbut only 0.5% females

Sex-Linked Traits Sex-Linked Traits Male and Female Male and Female

Sex-Linked Traits in Sex-Linked Traits in HumanHuman

Red/Green Red/Green ColorblindnessColorblindness

Hemophilia Hemophilia

HemophiliaHemophilia

Hemophilia Hemophilia Queen

Victoria of England was a carrier

1819-19011819-1901

XBXB Normal Female XBXb Carrier Female (normal) XbXb Disorder female

( you need two copies of the gene in females to express)

XBY Normal male XbY Disorder male

Why do you think sex linked traits effect men more than women?

Exit TicketExit Ticket

Would this person Would this person XXHH X Xhh have hemophilia? Is this have hemophilia? Is this male of female?male of female?

Would person Would person XXHHYY have have hemophilia? Is this male or hemophilia? Is this male or female?female?

Sex- Linked Cross Sex- Linked Cross

If a mother who is a carrier for Hemophilia has a child with a father who has normal blood? What percent of the children will have Hemophilia? What percent of the boys?

Sex-Linked CrossSex-Linked Cross

Cross a female that has normal vision with a male that is colorblind. What percent of their children will be colorblind?

PedigreePedigree

Offspring: Offspring: Shade in the trait Shade in the trait

expressed expressed

Problems with Chromosome Problems with Chromosome NumberNumber

5.5. Monosomy – only one of a particular Monosomy – only one of a particular type of chromosome (2n -1)type of chromosome (2n -1)

6.6. Trisomy – having three of a particular Trisomy – having three of a particular type of chromosome (2n + 1)type of chromosome (2n + 1)

7.7. Polyploidy – having more than two sets Polyploidy – having more than two sets of chromosomes; triploids (3n = 3 of of chromosomes; triploids (3n = 3 of each type of chromosome), tetraploids each type of chromosome), tetraploids (4n = 4 of each type of chromosome). (4n = 4 of each type of chromosome).