Genetics Genetics

Introduction

GREGOR MENDALGREGOR MENDAL:: THE FATHER OF GENETICSTHE FATHER OF GENETICS

AT 21 YEARS OLD HE JOINED THE MONASTARY IN BRUNN, AUSTRIA

HIS JOB WAS TO TEND TO THE GARDEN

IN 1851, HE ENTERED THE UNIV. OF VIENNA TO STUDY SCIENCE & MATH.

IN MATH HE LEARNED THE SUBJECT OF STATISTICS

STATISTICS HELPED W/HIS DISCOVERY OF HEREDITY:– THE TRANSMISSION OF

CHARACTERISTICS FROM PARENTS TO OFFSPRING.

MENDAL LATER RETURNED TO THE MONASTERY AND TAUGHT HIGH SCHOOL AND KEPT HIS GARDEN GOING.

HE STUDIED MANY TYPES OF PLANTS BUT HE IS MOST FAMOUS FOR...

PISUM SATIVUM, AKA:– GARDEN PEAS!

OBSERVATION OF 7 CHARACT. OF PEAS:– EACH OCCURRED IN

2 CONTRASTING TRAITS)

USING STATISTICS STATISTICS MENDAL ANALYZED THE DIFFERENCES HE OBSERVED!

1920s.  This shows a close up of the garden area. It is precisely here that Mendel grew his

peas. 

1. PLANT HEIGHT--LONG/SHORT

2. FLOWER POSITION ALONG STEM--AXIAL OR TERMINAL

3. POD COLOR--GREEN/YELLOW

4. POD APPEARANCE--INFLATED/ CONSTRICTED

5. FLOWER COLOR--PURPLE/WHITE

6. SEED TEXTURE--SMOOTH/WRINKLED

7. SEED COLOR--GREEN/YELLOW

PLANT CHARACTERISTICS

HIS OBSERVATIONS: FLOWER COLOR :

– PURPLE-FLOWERS PURPLE FLOWER– PURPLE-FLOWER WHITE-FLOWERING

PLANT HEIGHT:– TALL PLANT SEEDS-->

TALL PLANTS– TALL PLANT SEEDS-->

SHORT PLANTS

WHYWHY DO YOU

THINK THIS HAPPENED?

ANTHER: MALE REPRODUCTIVE PARTSTIGMA: FEMALE REPRODUCTIVE PART

FLOWER ANATOMYFLOWER ANATOMY

MENDEL’S METHODSMENDEL’S METHODS

HE CONTROLLED THE EXPERIMENT BY CHOOSING HOW THE PLANTS WERE POLLINATED.

POLLINATION:– POLLEN GRAINS FROM

ANTHER TRANSFERRED TO STIGMA

P generation: Parents

F1 generation: Offspring

F2 generation: Offspring of the F1 generation

Alleles

Alleles

DOMINANT & RECESSIVEDOMINANT & RECESSIVE

Dominant trait: The trait seen or observed

Recessive trait: The masked or hidden trait

PUNNETT SQUAREPUNNETT SQUARETOOL USED TO PREDICT THE

PROBABILITY OF A GENETIC CROSS.CAPITAL LETTER “A” REPRESENTS

DOMINANT ALLELEAllele: Variation of a Gene

– Gene: Eye color Alleles: Brown, Blue, Hazel

LOWERCASE LETTER “a” REPRESENTS recessive ALLELE

ImportantImportant TermsTerms

Genotype: The genetic blueprint or what the letter (allele) represents. Letter combinations– Examples: TT, Tt, tt

Phenotype: How an allele looks; the physical appearance– Examples: Tall and short

Important TermsImportant Terms•Homozygous: An organism with two alike alleles.

•Homo. Dominant•2 Capital letters•Ex. ZZ, BB, FF

•Homozygous Recessive•2 lower case letters•Ex. tt, bb, gg

•Heterozygous: An organism with two different alleles for a trait.

•Heterozygous Dominant: One capital letter and one lower case

•Ex. Gg, Hh, Zz

Punnett Square Examples

PUNNETT SQUAREPUNNETT SQUARE EXAMPLES EXAMPLES