11-1 The Work of Gregor Mendel Pg. 263

A. Gregor Mendel’s Peas 1. Genetics is the scientific study of inheritance.

Listen to this story….. Once upon a time there were two cute white bunnies in the wild. The two bunnies fell in love and had many baby bunnies. …..but there was one thing that could not be explained….

Listen to this story….. …where did the gray bunny come from?

A. Gregor Mendel’s Peas 2. Mendel, an Austrian monk, studied genetics using pea plants.

A. Gregor Mendel’s Peas 3. Pea plants undergo fertilization (joining of male and female reproductive cells) when pollen (male reproductive cells) joins the female reproductive cells in the ovaries.

A. Gregor Mendel’s Peas 4. The pea plants at Mendels Monastery were true-breeding, allowed to self-pollinate, producing identical copies.

A. Gregor Mendel’s Peas Mendel wondered what would happen if he pollinated two different plants?

B. Genes and Dominance 1. Mendel studied 7 traits. 2. Traits are specific characteristics that vary from one individual to another. – Examples: Plant Color, Plant Height, Seed Texture

Activity Break! Identify which of the following 10 human traits you have by placing a check mark beside that trait. Compare the traits you have with other students in the classroom. FIRST, lets predict which traits are MOST common!

Tongue Roller Non-Tongue Roller Attached Earlobes Unattached earlobes Dimples No Dimples Right-handed Left-Handed Widow's Peak Straight Hairline Left Thumb on top when Hands Crossed Right Thumb on top when Hands Crossed Hair on mid-digit of hand No hair on mid-digit of hand Bent little finger Straight little finger Second toe longer than big toe Second toe not longer than big toe

B. Genes and Dominance 3. P= Parental Generation F= Filial Generation 4. Offspring from parents with different traits are called hybrids.

B. Genes and Dominance 5. The hybrids Mendel produced, surprisingly, only showed the traits of one of the parents.

B. Genes and Dominance 6. Mendel concluded that traits were passed on as units, called genes, that come in two forms, called alleles.

B. Genes and Dominance 7. The law of dominance states that some alleles are dominant and some alleles are recessive.

C. Segregation Do the recessive alleles disappear?!?!?! Mendel Tested that too!!!!

C. Law of Segregation 1. Mendel crossed Filial one (F 1 ) plants to each other to produce Filial two (F 2 ) plants.

C. Segregation 2. Mendel suggested that during gamete formation (MEIOSIS), the alleles separate into different cells.

C. Segregation 3. The law of segregation states that alleles segregate (separate) from each other so that each gamete only carries one copy of each gene.