Genetics Study of heredity Genetics Mendel and pea

Genetics

�Study of heredity Genetics �Mendel and pea plants �Fertilization- sperm and egg join

�Trait �Ex. eye color, height �Hybrids- crosses between parents are true-breeding types

�Gene- sequence of DNA that codes for a specific trait �Ex. Eye color �Allele- version of a gene �Ex. blue eye color �Diploid organisms have two alleles

Types of Alleles �Dominant �Recessive

v Mendel’s Principle of Segregation: Two members of a gene pair segregate (separate) from each other during the formation of gametes. Animation of Segregation

Mendel’s Principle of Independent Assortment: Alleles for different traits assort independently of one another. Genes on different chromosomes behave independently in gamete production.

�Diploid- 2 sets of chromosomes �Haploid- 1 set of chromosomes -Gametes

�Genotype �Ex. BB �Phenotype �Ex. Brown eyes

�Homozygous �Heterozygous

Monohybrid cross

Probability and Genetics �Probability- likelihood that an event will occur �Multiplication rule �“AND” �Ex. What are the chances that you will have a boy and a boy? �Addition rule �“OR” �Ex. What are the chances that you will have a boy or a girl?

2 Genes �Law of segregation �Alleles for the same gene must separate into different gametes (eggs and sperm) � Ex. Bb � Gamete 1: B � Gamete 2: b

Law of Independent Assortment �Genes for different traits can segregate independently during the formation of gametes

The laws and performing a dihybrid cross �Dihybrid cross= 2 traits � 16 -square Punnett problem Steps: 1. FOIL the possible gametes for both parents 2. Create a 16 -square Punnett box and place parent gametes 3. Double-check you are doing it right by making sure all offspring have 4 letters, 2 of each kind!

Dihybrid Cross

Alternative Method �Make a 4 -square Punnett box for each individual trait and multiply the two results together �Utilizing the multiplication rule!

Shape of Earlobe Recessive Dominant

Eye Color Dominant Recessive

Shape of Hairline Dominant Recessive

Tongue Roll Dominant Recessive

Tongue Fold Recessive Dominant

Shape of Little Finger Recessive Dominant

Hair on Middle Joint Recessive Dominant

Hair Color Recessive Dominant Red Hair – Any shade Any Other Color Hair

Hair Type Dominant Recessive

Eyelash Length Recessive Dominant

Number of Fingers Recessive Dominant

Cleft Chin Recessive Dominant

Dimples Dominant Recessive

Freckles Dominant Recessive

Hand Clasping Dominant Recessive 55% of People 45% of People