2nd year

1. Genotype and Phenotype
What is the difference?

2. Review Words
 Characteristics – are the category of a trait –
 Example – eye color, height, likes/dislikes
 Traits – the physical, social, and emotional qualities of an
organism
 Example – blue eyes, tall, hates carrots
 Dominant Trait – when a majority of an organism shows the
trait.
 Example – most pea plants show as tall
 Recessive Trait – when a minority of an organism shows the
trait.
 Example – few pea plants show as short
 Alleles – all the possible choices for a characteristic
 Example – eye color – blue, brown, gray, green

3. Genotype
 How the genes code for a specific trait.
 If the trait is dominant it uses a capital letter
 Example – Tall (T)
 Ifthe trait is recessive it uses the same letter
but lower case
 Example – short (t)
 Genotypes always have two letters – one for
dad and one for mom

4. Types of genotype
 Purebred (homozygous) dominant – the genes
only have the dominant trait in its code.
 Example – Dominant Tall -- TT
 Purebred (homozygous) recessive – the genes
only have the recessive trait in its code.
 Example – Recessive short – tt
 Hybrid(heterozygous) – the genes are mixed
code for that trait.
 Example – hybrid Tall -- Tt

5. Phenotype
The outward appearance of the
trait.
How an organism looks
How an organism acts
How an organism feels

6. Tricks to remembering the difference
between Genotype and Phenotype
Genotype – deals with
GENE CODE.
Phenotype – deals with
looks you can take a
PHOTO with.