do now question

Do now question

What is genetics and why do scientists study genetics?

Intro to GeneticsMs. Bush

Genetics Unit

What are genes?

Why study genetics?

Gregor Mendel “Father of genetics”

• Born in 1822• Studied science and math

at Univ. of Vienna• Austrian Monk who

studied inheritance• Teacher and gardener• Worked with pea plants

and cross pollination

• Mendel did originally started his studies with mice not peas.

• The other monks did not approve of him breeding mice…plus they smelled bad!

Mendel and Pea Plant

“Pisum sativum”Garden pea

Mendel’s Experiments

Mendel’s Experiments

Mendel’s Laws

1. Law of Dominance – some traits are stronger than others and thus will appear more frequently in the offspring

2. Law of Segregation – alleles of same trait separate from each other during the formation of gametes (sex cells)

3. Law of Independent Assortment- genes for different traits can segregate independently during formation of gametes

Traits – Dominant and Recessive

Practice

Circle the following letters that represent dominant (stronger) traits?

T b M V c Y r w Q P L i

Circle the following letters that represent recessive (weaker) traits?

K U y E O c q A X m z R

Genotype and Phenotype

Genes are sorted in to the gametes (sex cells of an organism) and due to independent assortment, we can think of traits as sorting separate. Genotype-

Phenotype-

PracticeAssume Y means dominant yellow and y means recessive green. (Pure-breeding means YY or yy)•What is the phenotype and genotype of F1?•What is the phenotype(s) and genotype(s) of F2?

Homozygous and Heterozygous

Practice

Circle the homozygous recessive pairs:rr TT Tt Gg HH bb Nn WW yy Pp CC qq

Circle the heterozygous pairs:Oo ii LL Gg Jj DD ww VV bb zz Hh Ee SS kk

Circle the homozygous dominant pairs:Tt UU Rr Qq XX mm Dd Ff YY Oo BB Aa

Homework

Genetics Problem Set #1 due Wednesday, April 25.