1. Mr. Ernstes 7th Grade Milwood Magnet School
Genetics PowerPoint
Mr. Ernstes
7th Grade
Milwood Magnet School

2. Genetics Vocabulary Sex Chromosome Autosome Chromosomes
Determines the sex of an organism
XX in Females
XY in Males
Autosome Chromosomes
All the other chromosomes of an organism
Humans – pairs 1-22; 44 total.

5. Genetics Vocabulary Traits Allele
Inherited characteristics determined by your genes
Allele
Different types of genes
Example height of pea plants
T = tall pea plant
t = short pea plant

6. Genetics Vocabulary Homozygous Heterozygous
When both alleles are the same
Example: Pea Plant Height
TT or tt
Heterozygous
When the alleles are different
Tt or tT

7. Practice
In your groups answer whether the following genotypes are homozygous or heterozygous: Cc hh Tt
Xhy
XcbXN
HbsHbs

8. Genetics Vocabulary Dominant Written with capital letters
Whenever present the DOMINANT allele will be expressed
It “overpowers” the other recessive allele

9. Genetics Vocabulary Recessive Written with lower case letters
These are “dominated” by the dominant alleles
This means the trait is only expressed when there is NO dominant trait present
Example: Pea Plant Height
TT = Tall
Tt = Tall
tt = short

10. Genetics Vocabulary Genotype Phenotype Tells us what genes are present
CANNOT always tell this from the phenotype
This can then give us the phenotype
Phenotype
This is the physical appearance or characteristic of the genes
Can tell this from the genotype

11. Practice
What would be the genotype for a short pea plant when T=tall, t = short?
What would be the phenotype for someone with the following eye color genotype Bb (B = brown, b = blue)?
What would be the phenotype for someone with the following eye color genotype bb (B = brown, b = blue)?

12. Punnett Squares
Tool used in genetics to predict the probability of certain traits being passed from parents to offspring.