Introduction to Genetics

Heredity….

Gregor Mendel

Austrian Monk--Discovered a “pattern”

while working in the garden

PEAS have “traits” or characteristics

--color of flower--color of seed--height of plant

Pea Plant Experiment

Purple x WhiteFlower Flower

All offspring PURPLE

(Parents) P1

( Kids)F1

Mendel’s Experiment

Some TRAITS, such as purple color of the flower, OVERTAKES the other color white.

A dominant trait, if present, will “overtake” the other trait and will be expressed.

Therefore, PURPLE IS DOMINANT to white.

Pea Plant Experiment…. Part 2

Purple X Purple flower flower

¾ were purple ¼ were white

Mendel’s Experiment, part 2

Some traits will “reappear” ….such as the white color of the pea plant flower.

RECESSIVE traits often will “hide” in one generation but then “appear” in another.

WHITE FLOWER is RECESSIVE to the PURPLE FLOWER

Mendel’s Experiment OVERVIEW

Purple Flower x White Flower

All purple flowers

Purple flower x Purple Flower

¾ Purple Flowers¼ White Flowers

Generation 1

Generation 2

REALIZATIONS from MENDEL’s experiment

*Some traits are “dominant” and others are recessive

*The kids must “get information” from the parents

-- Genes control a “trait” Alleles are different versions of a gene

“P” purple (we will use CAPITAL letters for dominant traits)

“p” white (we will use LOWER CASE letters for recessive traits)

Additional Vocabulary

Phenotype is the “physical trait description”Purple flower or white flower

Genotype is the combination of “alleles or genes”

PP or Pp this would represent purplepp this would represent white

Gather information from your parents….

You need to collect some information from your parents and siblings (as well as yourself).

Use the next part to help you collect your data….

Traits….

Traits…

Traits…

Huber’s FamilyTraits Jeff Terra Ty

Forelock (widow’s peak)

No forelock No forelock No forelock

Dimples (cleft chin) No Yes Yes

Thumb Straight Straight Straight

Pinky Straight Bent Bent

Mid-Digit hair Yes No No

2nd Toe Shorter Longer Longer

Tongue Rolling Can roll Can roll ??