UNIT: Genetics How do monohybrid crosses show patterns of inheritance? For Review: Homozygous-when 2 alleles are the same (a.k.a.purebred) represented by: BB Heterozygous-when 2 alleles are different (hybrid) Ex. Bb Genotype-the genetic make up of an organism Ex. Bb (indicated by letters)  

UNIT: Genetics How do monohybrid crosses show patterns of inheritance? For Review: Phenotype-Physical appearance of the organism Ex. Brown eyes (indicated by the words/descriptions) Dominant- the allele that shows up (capital letter) Ex. Brown eyes are dominant over blue because B=brown and b=blue Recessive-allele is “hidden” by the dominant allele ex. Bb- b is the recessive allele.  

Monohybrid crosses Gregor Mendel wanted to cross or pollinate different pea plants with different traits. What is the model used to predict the chances of inheriting 1 trait? Punnett Square

How did Mendel use Punnett Squares to study why some pea plants’ flowers were purple and others were white? Monohybrid Cross Cross between individuals(plants) involving 1 trait ex. Pea plant color

Steps to a monohybrid cross 1. Determine which allele is dominant and which is recessive and Create a key for the dominant and recessive alleles ex. T= Tabby t=stripeless fur 2. Determine the genotypes of the parent cats. Ex. Tt x Tt Heterozygous(Hybrid) Tabby x Heterozygous(Hybrid) Tabby

Steps of monohybrid crosses 3. Figure out the sex cells produced by each parent during meiosis and label the Punnett square. Tt x Tt   T t T t sperm sperm egg egg

Steps of monohybrid crosses Bring letters down into each of the four boxes putting the capital letter first T t   T t

Steps of monohybrid crosses 4. While looking at the first generation of offspring, figure out what are the genotypes of the offspring? Genotype: What is the phenotype of the first generation (F1)? Phenotype: Steps of monohybrid crosses T t P1 TT   Tt   Tt  tt T t F1