1. Genetic Traits
TEKS 7.14A: The student will define heredity as the passage of genetic instructions from one generation to the next generation.
What is a trait?
A trait is a behavioral characteristic or physical attributes of an organism that are expressed by genes and/or influenced by the environment.

2. Bill Nye Science Guy - Genes
How Stuff Works? – The Future of Genetic Modification
Neil deGasse Tyson – NOVA, Explains why twins are not identical

3. Bill Nye the science guy - genes

4. Pbs/NOVA - cracking your genetic code
Neil degrasse tyson – nova, personal dna testing using saliva to find diseases

5. What is a trait?

6. Genetic Traits (post-homework)
Where did these traits come from?
From your biological parents. One set of chromosomes from your mom (23) and one set of chromosomes from your dad (23). Which make a total of 46 chromosomes (23 pairs).
Prokaryote vs. Eukaryote cells? Remember?
Prokaryotic (Archaebacteria, Bacteria, and some protists) do not have genetic material contained in a nucleus, but the genetic material is still present. Eukaryotic (other Protists, Fungi, Plants, and Animals) have genetic material contained in the nucleus.

7. What is a Gene?
A gene is a segment of DNA located on each chromosome.
Each gene has a particular form.
The genetic material is made of an organic compound called deoxyribonucleic acid (DNA).

8. What elements does an organic compound contain?
CARBON, and hydrogen, oxygen, nitrogen, phosphorus, and sulfur. SPONCH

9. An allele can either be dominant or recessive.
Within the nucleus, genes occur in pairs.
An allele is a form of a gene.
An allele can either be dominant or recessive.
If a dominant allele of a gene is present, the dominant trait will appear (show the phenotype) in an organism. A capital letter is used to represent a dominant allele. (Rr, RR)

10. In order for a recessive trait to appear (show the phenotype), both alleles of a gene must be recessive. A lower case letter is used to represent a recessive allele. (rr)

11. Complete handout: “How do genes determine traits?” And / or
Complete “Penny genetics” lab.

12. Scientists use a model called a Punnett Square to predict the outcome of a particular combination of parent traits. They predict the potential genotypes of the offspring of two parents with known genotypes.

13. The genotype is the possible combinations of alleles in a gene.
The expression of a gene is called a phenotype. (photo – what you see)
The genotype is the possible combinations of alleles in a gene.