The Work of Gregor MendelChapter 11-1

Transmission of characteristics from _______________________is called ___________________.

The _________ that studies _____ thosecharacteristics are _________ from onegeneration to the next is called___________________

heredity

Genetics

parents to offspring

SCIENCE how

passed on

The __________________ is _________________,

a monk whose _________ of genetic traits was the beginning of our _________________ about _____________________.

Gregor MendelFather of Genetics

study

understandinghow genes work

Mendel designed ____________ using__________ in the monastery garden

_______ part of flower makes ___________ (sperm)

__________ part of flower makes _______ cells

Pea plants

Pollen

experiments

MALE

FEMALEegg

In pea plants, the pollen normally joins with an egg from the _______ plant (=_______________ ) so seeds have “_________________”

Self pollinatingsame

ONE parent

MENDEL’S PEA EXPERIMENTSMendel started his experiments with

peas that were _________________ = if allowed to _________________ they would produce ____________________ to themselves.

true breeding

self pollinate

offspring identical

MENDEL’S PEA EXPERIMENTSMendel ____________________making parts and ____________from _______ plant.

This allowed him to_____________ plantswith ______________ characteristics and ________ the resultsdifferent

removed pollenadded pollen

another

cross-breed

study

A _____________________ is called a ____________

Mendel ______________ in peas.

specific characteristictrait

studied 7 traits

MENDEL’S EXPERIMENTS

____ generation (_________)

____ generation(______= offspring)___ generation

P1

F1

F2

parental

filial

Go to Section:

P Generation F1 Generation F2 Generation

Tall Short Tall TallTall Tall Tall Short

Section 11-1

Principles of Dominance

Go to Section:

P Generation F1 Generation F2 Generation

Tall Short Tall TallTall Tall Tall Short

Section 11-1

Principles of Dominance

Go to Section:

P Generation F1 Generation F2 Generation

Tall Short Tall TallTall Tall Tall Short

Section 11-1

Principles of Dominance

When Mendel ______________ PLANTS with 2 ______________ traits:(EX: Tall crossed with short)

He always found same pattern: 1. ONLY ______ trait ____________

in the ____ generation BUT . . .

2. ___________ trait ____________ in the ____ generation

in a _________ ratio

ONE showedF1

F2

3:1

crossed PURE contrasting

Missing returned

PATTERNS ARE THE KEY

Who is the “father” of genetics?

A. Robert HookeB. Charles DarwinC. Gregor Mendel

D. Anton Van Leeuwenhoek

What is it called when the pollen of a plant fertilizes an egg of the same plant?

Mendel decided that there must be a __________________ that ________each trait and that

__________ must be able to _______ the other.

pair of FACTORS

one factorcontrol

HIDE

We now know that Mendel’s ________________ carried onthe pair of________________

_________________

factors are geneshomologouschromosomes

________ gene _______ for atrait are called ___________.ALLELES

DIFFERENT

CHOICES

What are the “factors” that Mendel thought were

responsible for controlling traits?

A. Homologous chromosomesB. MeiosisC. MitosisD. Genes

Different gene choices for a trait are called

____________.

_______________ = An allele that ________ the presence of another allele. Dominant alleles represented with CAPITAL letters.

_________________ = An allelethat __________________ the

presence of another allele. Recessive alleles represented with lowercase letters.

DOMINANT

RECESSIVE

HIDES

is hidden by

Why did the recessive trait disappear in the F1 generation and reappear in the F2?

The pattern corresponds to the ____________ of ______________ during____________________MEIOSIS

movementchromosomes

WHAT DOES MEIOSIS HAVE TO DO WITH IT?

REMEMBER

_____________ chromosomes________________during ANAPHASE I= _________________SEGREGATION

HOMOLOGOUS

SEPARATE

____ offspring __________ an allele for tallness from their _______ parent and an allele for shortness from their ________ parent.

The F1 plants ALL ___________ but are ___________ an

allele for _____________

TALLSHORT

LOOK TALL

F1 received

carrying shortness

alleles are separated when the F1 plants ______________

When these gametes recombined to make the F2 generation, the _____________ trait _______________ in ¼ of the offspring

EXPLAINING the F1 CROSS

LAW OF ___________________SEGREGATION

recessive

made gametes

reappears

PROBABILITY & PUNNETT SQUARES

11-2

O T T F F S S E __

What comes next?

O T T F F S S E __

It’s EASY if you know the PATTERN!(Just like Punnett Squares)

NE

WO

1 2 3 4 5 6 7 8

HREE

OUR

IVE

IX

EVEN

IGHT

9NINE

It can be written as a:Fraction ____

Percent ____Ratio ____

____________________is the __________ that a

particular _________________

PROBABILITY

1/425%

1:3

likelihoodevent will occur

COIN FLIPThere are 2 possible

outcomes:HEADS TAILS

The chance the coin will land on either one is:____ ____ ____

Alleles segregate randomly just like a coin flip. . . So can use probability to predict outcomes of genetic crosses.

1/2 50% 1:1

PROBABILITIES_____ outcomes ______ affect _________ones

_____________works ______ in ___________ a ________ number of events.

If last coin flip was heads… there is still a 50/50 chance the next flip will be heads too.

The more flips. . . The closer results will be to the expected 50:50 average.

PAST DON’T FUTURE

Probability best predictinglarge

DOMINANT/RECESSIVE_____________ allele is represented by a

____________ letter.(usually the first letter of the trait)

____________ allele is represented by the SAME_________________ letter.

EX: Tall = ______

Short =______

capital

lower-case

Tt NOT S for short

Dominant

Recessive

HOMOZYGOUSHETEROZYGOUS

When both alleles in the pair are the _______, the organism is _______________ or __________

EX: ____ or ___When both alleles in the pair are

_____________, the organism is_________________ or _____________

Ex: ____HETEROZYGOUS HYBRID

HOMOZYGOUS PURESAME

TT tt

DIFFERENT

Tt

Using the alphabet letter D

text a homozygous genotype.

Using the alphabet letterG

text a heterozygous genotype.

PHENOTYPE/GENOTYPEThe ________________ of an organism

is its _____________

The ____________of an organism isits _____________

GENOTYPE

PHENOTYPE

genetic makeup

appearance

MAKING A CROSS for only a __________ trait =____________________

A Punnett square for a MONOHYBRID CROSS looks like this:

MONOHYBRID CROSSONE GENE

PUNNETT SQUARESare used to show possible offspring

from a cross between 2 parents

_______________ go at top and on left side

Boxes show _______________________________

T T

T

tpossible offspring combinations

Parent alleles

1. ___________ what _________________ are2. ________correct__________ square __________3. ______ possible_______________________4. ______ boxes with _____________________5. Determine ____________of_____________& ____________

STEPS FOR MAKING CROSSES

Figure out parent allelesChoose Punnett sizePut in parent gametesFill in offspring combinations probabilities phenotypes

genotypes

IN PEA PLANTSTall is dominant over short TALL = ____

SHORT = ____T

tLET’S MAKE A CROSS!

PURE TALL PURE SHORTX

PURE TALL parentWhat are the parent alleles?

T T _________

T T

HOMOZYGOUS

What gametes can it make?

PURE SHORT parent What are the parent alleles?

t t _________

t t

HOMOZYGOUS

What gametes can it make?

GENOTYPE _____ PHENOTYPE _______

_____ of the offspring

____ % ___/4 will be

T T

t

t

T t T t

T t T tTt TALL

ALL

1004

HYBRID TALL parent What are the parent alleles?

T t _________

T t

HETEROZYGOUS

What gametes can it make?

GENOTYPES¼ = _____½ = _____¼ = _____

T t

T

t

T T T t

T t t t

PHENOTYPES ____ or ____% _________ ____ or ____% _________

TT

75

Tttt

3/41/4 SHORT

TALL25

PRACTICE MAKING GAMETES for a MONOHYBRID CROSS

Tall = ____ Round seeds = ___ Short = ____ Wrinkled seeds = ___

Tt

Rr

Homozygous Tall parent =

What gametes can it produce?

What are the possible gametes?

T T

T T

PURE wrinkled parent =

What gametes can it produce?

What are the possible gametes?

rr

r r

Heterozygous Round parent =

What gametes can it produce?

What are the possible gametes?

R r

R r

Hybrid Tall parent =

What gametes can it produce?

What are the possible gametes?

Tt

T t