1. 2- Science Starter: Vocabulary Words (Two)
Agenda AR
Book
Tuesday, Sept Day 2
1. Please have these
Items on your desk.
Science Starters
Sheet
Venn
Diagram
2- Science Starter: Vocabulary Words (Two)

2. Vocabulary Words:
Genotype: An organisms genetic make-up, allele combinations.
Phenotype: An organism’s physical appearance, or visible traits.
Baker 2003/2004

3. Whose got Genes? Genes, Heredity, & DNA www.sciencequeen.net
Baker 2003/2004

4. What are genes?
Genes are a segment of DNA on a chromosome that controls a particular trait.
Genes are located on the chromosomes in the nuclei. Each organims has a fixed number of chromosomes.
Humans have 23 pairs (46) chromosomes.
Genetics is the study of how traits are passed on from one generation to another
                                  
Baker 2003/2004

5. What is GENETICS?
The study of how traits are inherited through the interactions of genes.
Baker 2003/2004

6. Define TRAIT Ways of looking, thinking, or being
Traits that are genetic are passed down through the genes from parents to offspring
Baker 2003/2004

7. Describe RECESSIVE
A trait that is covered over, or dominated, by another form of that trait and seems to disappear
Hidden when the other copy of the gene contains the dominant allele.
A recessive allele shows up only when there is no dominant allele present
Shown with a lower-case letter
Baker 2003/2004

8. Describe DOMINANT
A trait that covers over, or dominates, another form of that trait
Trait that always shows up, even when only one of the two alleles is in the dominant form
Shown by a capital letter
Baker 2003/2004

9. Define GENOTYPE
An organism's genetic makeup
Baker 2003/2004

10. Outward physical appearance and behavior of an organism
Define PHENOTYPE
Outward physical appearance and behavior of an organism
Baker 2003/2004

11. What is a PUNNETT SQUARE?
Used to determine the likely hood that the offspring receives a certain trait.
An uppercase letter stands for a dominant allele
Lowercase letters stand for recessive alleles
Baker 2003/2004

12. Punnett Squares
Sample Problem 1.   In roses, red flowers are dominant over white flowers. What are the possible offspring when a homozygous red rose is crossed with a homozygous white rose.
Baker 2003/2004

13. Generation 1 (I Do) R R Red rose = RR white rose = rr R r R r r
Genotype
4 Rr
Phenotype
100% Red Rose R r r R r
Baker 2003/2004

14. Generation 2 (We do) R r r r R r r Red rose = Rr white rose = rr R r r
Genotype
2 Rr 2 rr
Phenotype
50% Red 50% White R r r r r
Baker 2003/2004

15. Generation 3 (You do) R r Red rose = Rr R r R R R Genotype
Phenotype
75% Red 25% White R r r r r
Baker 2003/2004

16. Whose got Genes? Part 2
Genes, Heredity, & DNA
Baker 2003/2004

17. Who was Gregor Mendel?
Austrian monk who studied mathematics and science
As a boy he could predict the possible types of flowers and fruits that would result from crossbreeding two plants in his father’s garden
Picture taken from biography.com
Baker 2003/2004

18. Who was Gregor Mendel?
Curiosity about the connection between the color of a pea flower and the type of seed that same plant produced inspired him to begin experimenting with garden peas in 1856.
Made careful use of scientific methods, which resulted in the first recorded study of how traits pass from one generation to the next.
Baker 2003/2004

19. The passing of traits from parent to offspring
Define HEREDITY
The passing of traits from parent to offspring
Baker 2003/2004

20. Define ALLELE The different forms of a trait that a gene may have
One form of a gene
Baker 2003/2004

21. What is HOMOZYGOUS? Both alleles [forms of the gene] are the same
When offspring inherit two dominant genes, (one dominant gene from each parent) they are said to be homozygous dominant
When offspring inherit two recessive genes, (one recessive gene from each parent) they are said to be homozygous recessive AA aa
Baker 2003/2004

22. What is HETEROZYGOUS? When alleles occur in different formsAa
What is HETEROZYGOUS?
When alleles occur in different forms
When offspring inherit one dominant gene and one recessive gene, they are said to be heterozygous
Since the dominant gene will be expressed, they are said to be heterozygous dominant
Baker 2003/2004

23. Generation 1 B Brown Eyes are Dominant to b Blue Eyes B b Heterozygous
Homozygous recessive b b B b b
Genotype
2 Bb 2bb
Phenotype
50% Brown
50% Blue B b b b b
Baker 2003/2004

24. Generation 2 B Brown Eyes are Dominant to b Blue Eyes B B
Homozygous Dominant
Homozygous Recessive B b B b b
Genotype
4 Bb
Phenotype
100% Brown Eyes b B b B b
Baker 2003/2004

25. Generation 3 B Brown Eyes are Dominant to b Blue Eyes B B
Homozygous Dominant
Heterozygous B B B B B
Genotype
2 BB 2 Bb
Phenotype
100% Brown Eyes B b b B b
Baker 2003/2004

26. References
Slideshow adapted from
Baker 2003/2004