1. Earn 5 extra points on last Friday’s test.
Warm Up
Earn 5 extra points on last Friday’s test.
Write the balanced chemical reaction for photosynthesis and cellular respiration.
Include where each reaction takes place and label each molecule.

2. What Do They Have In Common?

3. Genes and Heredity
McDougall Littel

4. Parents and Offspring Are Similar
You are an individual who has a unique combination of characteristics.
These characteristics are also known as traits.
Many of your traits may resemble those your parents like your hair color, eye color, and blood type.
These characteristics are called inherited traits.

5. Parents and Offspring Are Similar.
Some traits are acquired, not inherited.
An acquired trait develops during your life.
Learned behaviors are one type of acquired
trait.
Reading
Writing
Riding a bike
Acquired traits cannot be transmitted genetically.

7. Genes Are On Chromosome Pairs.
A gene is a unit of heredity that occupies a specific location on a chromosome and codes
for a particular characteristic or trait.
Heredity is the passing of genes from parents
to offspring.

8. Genes are on Chromosome Pairs
Cells contain pairs of chromosomes, one from each parent.
The chromosomes in a pair are called homologs.
They have the same size and shape, and carrying genetic information for particular traits.
The genes code for the expression of traits.

9. Genes Are On Chromosome Pairs
Chromosomes come in pairs.
The various forms of the same gene are called alleles (uh-LEELZ).
Examples: height, eye color, hair color, tongue roll.
Alleles AA Bb Cc DD ee
Each member in a pair is called a homolog.

11. Each Species has a Certain Number of Chromosomes.
Chimpanzees have 24 pairs of chromosomes.
Fruit flies have 4 pairs of chromosomes.
Humans have 23 pairs.
Human chromosomes are numbered 1-22.
The 23rd pair are the sex chromosomes.
For a total of 48 chromosomes.
8 in all.
46 total
XX - chromosomes for Females.
XY - for chromosomes Males.

14. Gregor Mendel Gregor Mendel is the father of genetics.
He investigated the inheritance of traits among pea plants.

16. Alleles Interact to Produce Traits.
Genotype is the name for the genes an organism has.
Your genotype is not always obvious from your phenotype.
Sometimes your genes contain information that is not expressed in your phenotype.
It’s what we can’t see.

17. Alleles Interact to Produce Traits.
An organism’s phenotype describes the actual characteristics that can be observed.
It’s what you can see.
-height
-size of your feet
-baldness
Observable traits and are part of your phenotype.

18. Dominant and Recessive Alleles
A dominant allele is one that is expressed in the phenotype.
-B = Brown eyes
-b= Blue eyes
-The BB and Bb genotype would produce an offspring with brown eyes because brown eyes are dominant.

19. Dominant and Recessive Alleles
A recessive allele is one that is expressed in the phenotype only when two copies of it are present on the homologs.
-b (blue) is recessive
-bb = blue eyes
Two brown haired parents produce a blonde child.

20. Dominant and Recessive Alleles
If both alleles are the same, the organism is homozygous, or purebred, for that trait
AA, BB, aa, bb
If the two alleles are different, the organism is heterozygous, or hybrid, for that trait.
Aa, Bb, Cc, Dd, Ee, Ff

21. Dominant and Recessive Alleles
Dominant alleles are always written with a capital letter.
TT, AA, GG, CC, UU
Recessive alleles are always written with a lowercase letter.
tt, aa, gg, cc, uu

22. What Do They Have In Common?

23. They Share the Same Gene Pool