1. Cleft Chin
Widow’s Peak
Hitchhikers
Thumb
Tongue Rolling

2. Genetics

3. Genetics
Study of how traits are inherited through the interaction of genes

4. Heredity The passing on of traits from parent to offspring
EX: blue eyes, brown hair, or a hitchers thumb

5. Trait Characteristics that are inherited
EX: A characteristic, is tallness or shortness, blue eyes or brown eyes

6. Alleles Different forms of a trait that a gene may have
Each sex cell (sperm or egg) has 1 allele for each trait
EX: 1 allele for Tallness
EX: 1 allele for Shortness

7. Dominant Trait
Dominant- a trait that is expressed and covers up the recessive form
It is always written as an Uppercase letter
EX: for the allele of Tallness, you will use the letter T
You only need 1 dominant allele for a trait to show

8. Since tallness is dominant, she will be tall either way
EX: Tallness
TT or Tt
Since tallness is dominant, she will be tall either way
Only Need
1 Dominant
Trait

9. Recessive Trait Trait that can be masked by the dominant trait
ALWAYS use a lowercase letter and it goes second
EX: For shortness you would use a lowercase t
Tt or tt

10. Recessive
You NEED 2 alleles for a recessive trait to show
EX: tt

11. trait masks the recessive
The dominant
trait masks the recessive
LOWERCASE because
it’s RECESSIVE Tt tt

12. Genotype The genetic makeup The allele combination of an organism
EX: Tt, TT, or tt

13. Phenotype The way an organism looks and behaves
EX: tall, short, blue eyes, brown eyes
You can’t always tell what a genotype is by looking at someone’s phenotype

14. Phenotype

15. Heterozygous or Hybrid
Offspring has different forms of trait
EX) Dd, Tt, or Bb

16. Homozygous
Same forms of a trait
EX: DD, TT,tt, bb, BB

17. Cleft Chin
Widow’s Peak
Hitchhikers
Thumb
Tongue Rolling

18. Gregor Mendel He was the “father of genetics” He studied Pea Plants
He was the first person to successfully predict outcomes of specific traits
He came up with the 3 Laws of heredity

19. Mendel’s Laws of Heredity
1) Rule of Unit Factors
2) The Law of Segregation
3) The Law of Independent Assortment

20. The Rule of Unit Factors:
An organism has 2 alleles for a trait
The 2 alleles are on different copies of chromosomes, one from the female parent & one from the male parent
EX: Tt, TT, or tt

21. B and b come from MALE
B and b come
from
Female

22. The Law of Segregation
Each gamete (sex cell) receives 1 allele for a trait from each parent
During fertilization, the gametes randomly pair

23. The Law of Segregation What is happening to the A and a from the dad?
What is happening to the A and a from the mom

24. The Law of Independent Assortment
Genes of different traits are inherited INDEPENDENTLY and RANDOMLY of each other
EX: The height of a plant and color of the seed are inherited independently of each other

25. color and shape of the seed
Pea Plants
Their traits are
color and shape of the seed

26. Mistakes in Meiosis

27. Non-Disjunction
a type of mistake in meiosis that happens to the CHROMOSOME
It is the failure of homologous chromosomes to separate properly

28. 2 things can happen
a) Have extra chromosomes
b) Missing chromosomes

29. Extra Chromosomes EX: Down Syndrome
When chromosome # 21 does not fully separate, and there is an additional chromosome
A person with down syndrome has 3 chromosomes instead of 2, which is called Trisomy 21
Instead of having 46 chromosomes, they have 47

31. Extra Chromosome EX: Polyploidy
Polyploidy is when there is a total LACK of separation of homologous chromosomes
The gamete (sperm/egg) inherits an entire EXTRA set of chromosomes

32. Polyploidy
Polyploidy is rare in animals, but if it occurs it will result in death of a zygote
BUT, it is frequent in PLANTS
Plants that have polyploidy are larger, healthier, and are of greater commercial value

33. Polyploidy

34. Missing Chromosomes
If a chromosome is missing, the organism will most likely not survive
It is referred to as “monosomy”
EX: Turner syndrome

35. Human females have only 1 single X chromosome instead of 2 X’s
Turner Syndrome

36. How to detect Genetic Disorders
Cells are extracted from a person
The Cells are stained to reveal a banding patterns
Chromosomes are identified, and arranged in homologous pairs
This chart is called a Karyotype, and is used to detect chromosomal abnormalities

38. Chromosomes # 1-22 are called Autosomes

39. Sex Determination: Chromosomes # 23

40. ADD THIS PLEASE SPERM determines the sex of a child
The sperm is either X or Y
The egg is ALWAYS a X
XX is female
XY is male