Your “Do Now” 1/30

1. Your “Do Now” 1/30 • Complete the weekly Pre-Quiz (up front) • Write our next 2 learning targets: • I can describe and explain the differences between dominant and recessive traits • I can explain Mendel’s laws of segregation and independent assortment

2. Agenda 1/30 • Exploring different types of traits • Ch 11 Notes #3 • Traits activity (online)

3. Exploring different types of traits • Work with a partner • We’ll discuss results in 7 minutes

4. Exploration Discussion • What was the baby left handed? • When was the baby right handed? • Can two right-handed people have a left-handed baby?

5. CH 11 Notes #3 1/30Traits & Inheritance

6. Starting on the back of Notes #3

7. Dominant Trait • Description: An allele that hides another allele for the trait • Example in Humans: Being right-handed • Symbol: Capitol letters (R, B, T) Right-handed Left-handed Baby is Right-handed

8. Recessive Trait • Description: An allele that gets hidden when it’s paired with another allele for the trait • Examples in humans: being left-handed • Symbol: lowercase letters (r, b, t) Right-handed Left-handed Baby is Right-handed

9. Dominant or Recessive? Blue-eyed allele + Brown-eyed allele = Brown-eyed person • Blue-eyed is ___________________ • Brown-eyed is __________________

10. Front Side of Notes #3

11. Describing an organism • GENOTYPE: The letters coding for a trait (“Bb”)The genes present in the DNA of an organism • Example: bb, Rr, Tt • Represented by 2 letters for a gene: “bb” for blue eyes Blue eyes Blue eyes

12. Describing an organism • PHENOTYPE: The appearance of a trait • Example: Having blue eyes

13. What’s the difference? • An organism can have a gene for a trait without showing it! • Allele for left-handed doesn’t mean person will be left-handed

14. So what? • This means we can’t always tell genotype by observing phenotype! • Example: A right-handed person can carry a gene for being left-handed

15. Describing genotypes • If an organism has two of the same allele for a trait it’s called HOMOZYGOUS • Example: Right-handed allele + Right-handed allele Right-handed Right-handed

16. 2 types of Homozygous • Homozygous dominant • Two dominant alleles. • Example: RR for right-handed • Homozygous recessive • Two recessive alleles • Example: rr for left-handed

17. Heterozygous • Rr

18. Describing genotypes • If an organism has two different alleles for a trait it’s called HETEROZYGOUS • Example: Left-handed allele + Right-handed allele • Genotype: Rr Right-handed Left-handed

19. What would it be?homozygous dom., homozygous rec., or heterozygous? • Brown eye allele + Brown eye allele • Brown eye allele + Blue eye allele • Left-handed allele + Right-handed allele • Right-handed allele + Right-handed allele

20. Gregor Mendel • An Austrian monk known as the father of genetics.

21. Gregor Mendel • Experimented with pea plants • Easy to care for • Simple traits to observe

22. Mendel’s Laws 1. LAW OF SEGREGATION: When gametes are formed, the two alleles responsible for the trait are separated from each other. Allele for Brown eyes Allele for Brown eyes

23. Allele for Brown eyes Allele for Brown eyes

24. Mendel’s Laws 2. LAW OF INDEPENDENT ASSORTMENT: As gametes form, alleles on different chromosomes sort independently from each other. Brown eyes Brown eyes <-OR-> Left-handed Left-handed

26. Mendel’s Laws 2. LAW OF INDEPENDENT ASSORTMENT: As gametes form, alleles on different chromosomes sort independently from each other. Brown eyes Brown eyes <-OR-> Left-handed Left-handed

27. Practice Time! • Work alone or with a partner • If it’s not done, it’s due tomorrow