The Work of Gregor Mendel Chapter 11-1

Transmission of characteristics from _______________________is called ___________________. The _________ that studies _____ those characteristics are _________ from one generation 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 Mendel Father of Genetics study understanding how genes work

Mendel designed ____________ using __________ in the monastery garden _______ part of flower makes ___________ (sperm) __________ part of flower makes _______ cells Pea plants Pollen experiments MALE FEMALE egg

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

MENDEL’S PEA EXPERIMENTS Mendel started his experiments with peas that were _________________ = if allowed to _________________ they would produce ____________________ to themselves. true breeding self pollinate offspring identical

MENDEL’S PEA EXPERIMENTS Mendel ____________________ making parts and ____________ from _______ plant. This allowed him to _____________ plants with ______________ characteristics and ________ the results different removed pollen added pollen another cross-breed study

A _____________________ is called a ____________ Mendel ______________ in peas. specific characteristic trait studied 7 traits

MENDEL’S EXPERIMENTS ____ generation (_________) ____ generation (______= offspring) ___ generation P1P1 F1F1 F2F2 parental filial

Go to Section: P Generation F 1 Generation F 2 Generation TallShortTall Short Section 11-1 Principles of Dominance

Go to Section: P Generation F 1 Generation F 2 Generation TallShortTall Short Section 11-1 Principles of Dominance

Go to Section: P Generation F 1 Generation F 2 Generation TallShortTall 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 ___________ trait ____________ in the ____ generation in a _________ ratio ONE showed F1F1 F2F2 3:1 crossed PURE contrasting Missing returned

PATTERNS ARE THE KEY

Who is the “father” of genetics? A. Robert Hooke B. Charles Darwin C. 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 factor control HIDE

We now know that Mendel’s ________________ carried on the pair of________________ _________________ factors are genes homologous chromosomes

________ gene _______ for a trait are called ___________. ALLELES DIFFERENT CHOICES

What are the “factors” that Mendel thought were responsible for controlling traits? A. Homologous chromosomes B. Meiosis C. Mitosis D. Genes

Different gene choices for a trait are called ____________.

_______________ = An allele that ________ the presence of another allele. Dominant alleles represented with CAPITAL letters. _________________ = An allele that __________________ 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 F 1 generation and reappear in the F 2 ? The pattern corresponds to the ____________ of ______________ during ____________________ MEIOSIS movement chromosomes

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 F 1 plants ALL ___________ but are ___________ an allele for _____________ TALL SHORT LOOK TALL F 1 received carrying shortness

alleles are separated when the F 1 plants ______________ When these gametes recombined to make the F 2 generation, the _____________ trait _______________ in ¼ of the offspring EXPLAINING the F 1 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) NENE WOWO HREEHREE OUR OUR IVEIVE IXIX EVENEVEN IGHTIGHT 9 NINENINE

It can be written as a: Fraction ____ Percent ____ Ratio ____ ____________________ is the __________ that a particular _________________ PROBABILITY 1/4 25% 1:3 likelihood event will occur

COIN FLIP There 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. 1/250%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. PASTDON’T FUTURE Probability best predicting large

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 T t NOT S for short Dominant Recessive

HOMOZYGOUS HETEROZYGOUS 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 PURE SAME TT tt DIFFERENT Tt

Using the alphabet letter D text a homozygous genotype.

Using the alphabet letter G text a heterozygous genotype.

PHENOTYPE/GENOTYPE The ________________ of an organism is its _____________ The ____________of an organism is its _____________ GENOTYPE PHENOTYPE genetic makeup appearance

MAKING A CROSS for only a __________ trait = ____________________ A Punnett square for a MONOHYBRID CROSS looks like this: MONOHYBRID CROSS ONE GENE

PUNNETT SQUARES are used to show possible offspring from a cross between 2 parents _______________ go at top and on left side Boxes show ____________ ___________________ T TtTt possible offspring combinations Parent alleles

1. ___________ what _________________ are 2. ________correct__________ square __________ 3. ______ possible_______________________ 4. ______ boxes with _____________________ 5. Determine ____________of_____________& ____________ STEPS FOR MAKING CROSSES Figure out parent alleles Choose Punnett size Put in parent gametes Fill in offspring combinations probabilities phenotypes genotypes

IN PEA PLANTS Tall is dominant over short TALL = ____ SHORT = ____ T t LET’S MAKE A CROSS! PURE TALL PURE SHORT X

PURE TALL parent What 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 TT t t T tT tT t T tT t T tT t TALL ALL 100 4

HYBRID TALL parent What are the parent alleles? T t _________   T t HETEROZYGOUS What gametes can it make?

GENOTYPES ¼ = _____ ½ = _____ ¼ = _____ Tt T t T TT T T t T tT t t tt t PHENOTYPES ____ or ____% _________ ____ or ____% _________ TT 75 Tt tt 3/4 1/4 SHORT TALL 25

PRACTICE MAKING GAMETES for a MONOHYBRID CROSS Tall = ____ Round seeds = ___ Short = ____ Wrinkled seeds = ___ T t R r

Homozygous Tall parent = What gametes can it produce? What are the possible gametes?   T TT

PURE wrinkled parent = What gametes can it produce? What are the possible gametes?   rr rr

Heterozygous Round parent = What gametes can it produce? What are the possible gametes?   R r Rr

Hybrid Tall parent = What gametes can it produce? What are the possible gametes?   Tt T t