1. Golden Doodle Blending Theory - offspring are a straight mix
A Brief History
In the past, people did not understand how traits were inherited, but there were many guesses based on things that could be observed.
Two theories emerged….
Blending Theory - offspring are a straight mix
Particulate Theory - traits are inherited as "particles", offspring receive a "piece" from each parent, some pieces may hide the others
Golden Doodle

2. Who was Gregor Mendel? GENETICS – study of heredity
He was known as the “FATHER OF GENETICS”
He discovered how traits were inherited
GENETICS – study of heredity
HEREDITY – the passing of traits from parents to offspring

3. Mendel’s Peas Mendel did his study on pea plants
which have many traits
tall/short
purple /white flowers
round/wrinkled seed

4. Pea plants can be self-fertilized or cross-fertilized

5. True-Breeding Plants - always create plants that look like themselves
Hybrids – offspring of true- breeding plants
Tall x Short = Hybrid

6. Some traits are dominant over others.
Tall x Short = all tall offspring (hybrids)
*Tall is the dominant trait
* Short is recessive

7. Mendel discovered that each trait is controlled by two factors (alleles)
Genes – factors that determine your traits
Genes are located on chromosomes

8. Quick Check 1 - What do we know so far?
1. The “Father of Genetics” is ____________
2. Genetics is the study of _____________, which is how traits are passed from _________ to ____________
3. Mendel studied what organism? ____________
4. If one trait covers up another one, we say that it is ______________, the one that is covered up is ______
5. A “true-breeding” plant is one that can only produce plants like itself a) true b) false
6. If a tall and a short plant are crossed, it will create a
a) zygote b) gene c) hybrid

9. Explaining the Cross
When a parent makes sperm or eggs, their genes separate         (PRINCIPLE OF SEGREGATION)
The GAMETES (egg or sperm) contain either a T allele (tall) or a t allele (short)

10. Mendel’s Experiments
Draw the crosses

13. GENOTYPE  -  what genes, letters, the organism has (TT, Tt, tt)
PHENOTYPE   - what it looks like (tall or short)

14. 2. Who was the father of genetics? _________
Quick Check 2 - What do we know so far?
1.   The passing of traits from parents to offspring is known as  ____________________
2.  Who was the father of genetics?  _________
3.  Genes are located on _______________
4.  Every gene is made of two
a. genotypes b. alleles c. cells
5. The organism’s outward appearance, such as wrinkled seeds are referred to as the a) phenotype b) genotype

15. 6. The letters (ex. RR) that represent the traits are referred to as the a) phenotype b) genotype
7. An organism that has two different alleles, or letters, such as Rr is: a) homozygous b) heterozygous
8. 7. An organism that has two of the same alleles, or letters, such as RR is: a) homozygous b) heterozygous
9. Which of the following sets would represent Mendel’s Parent (P) generation?
a) RR x RR b) Rr x Rr c) RR x rr
10. When two different alleles occur together, such as R r, the one that is expressed is a) dominant b) recessive

16. What does this letter actually represent?
11. What is the diagram shown below called?
What does this letter actually represent?

20. Human Chromosomes
Karyotype = picture of chromosomes arranged in pairs & organized by size
Humans have 46 chromosomes
2 of these are sex chromosomes
             XX = female XY = male
The other 44 chromosomes are known as autosomes

22. NONDISJUNCTION
Failure of chromosomes to separate in meiosis – results in an egg (sperm) with too many or too few
Down Syndrome (extra #21)
Klinefelter Syndrome (XXY)
Turner Syndrome (XO)
Supermale (XYY)

23. Down Syndrome
- caused by an extra chromosome (trisomy 21)

24. Edward Syndrome
- caused by an extra chromosome (trisomy 18)
Median life expectancy is 4 days. However, about 5-10% survive beyond one year

25. Trisomy – 3 chromosomes Monosomy – 1 chromosome

28. Checking in 1:
1.  A picture of a person's chromosomes is called a _____.
2.  In this pictures, chromosomes are arranged in  
pairs according to their ___________.
3.  Humans have ______ pairs of chromosomes.
4.  The last set of chromosomes is the _____ chromosomes.
5.  Males have what sex chromosomes?  ______
6.  A person who has an extra chromosome #21 has what disorder? __________
7.  If a person has XXY for sex chromosomes, he has what disorder? _________________
8.  As a woman gets _______, her risk for having a child with down syndrome increases.
9.  A human has 2 sex chromosomes, the other 44 chromosomes are called ______________.
10. When chromosomes fail to separate during meiosis,  ___________ has occurred.

29. Human Traits To study inheritance, biologists use pedigree charts
Shows relationships within a family

31. Many traits are strongly influenced by environmental factors
Not all Human Traits can be traced back to a single gene
Many traits are strongly influenced by environmental factors
(ex: height, weight, personality)

32. Human Genome Our complete set of genetic info
Includes thousands of genes
Base sequences of many genes identified

33. BLOOD TYPES
Genes controlling blood types were 1st genes to be identified
ABO & Rh blood groups ( + and - )

34. ABO Blood Group Multiple Allele Trait
Controlled by 3 alleles:  A, B, O
A and B are codominant
O is recessive to both A and B
The blood type is the phenotype

35. (universal recipient)
Genotype
Blood Type
AA, AO
Type A
BB, BO
Type B
AB codominant
Type AB
(universal recipient)
OO recessive
Type O (universal donor)

36. Blood Types Practice
Mom has type A blood (genotype AO), dad has type AB blood. What blood types are possible among their children?
Mom has type B blood (genotype BO), dad has type O blood. What blood types are possible among their children?

37. Human Genetic Disorders
Phenylketonuria (PKU)
Tay – Sachs disease
Albinism                          * all recessive

38. Other animals can be albino too..

39. Sickle-Cell Disease codominant (AA, Aa, aa )
heterozygous is resistant to malaria

40. Achondroplasia (dwarfism)
Huntington’s disease
* Both dominant

41. Checking in 2: 1. Achondroplasia is another name for ____________
2.  What are the four possible blood types? _______
3.  Is albinism dominant or recessive? _________
4.  If two people are both heterozygous for sickle cell trait, what is the chance they they will have a child with sickle cell disease?
5.  If a person with type A blood is married to person with type O blood, what blood types are possible in their children?
6.  The human _______ describes all the genes found in humans.
7.  What type of chart is used to study a trait in a family? __

42. Genes located on sex chromosomes follow different patterns of heredity
Genes located on sex chromosomes follow different patterns of heredity.  Males are more likely to be affected by these genes. 

43. ALL GENES ARE LOCATED ON CHROMOSOMES
Some genes are located on the SEX CHROMOSOMES  ( X and Y)
Genes on the X chromosome may affect boys different from girls
These are called SEX-LINKED GENES

44. EXAMPLES: SEX LINKED GENES
Coat color in cats:  Black, Orange,  Calico
X B X B  = black, female
X O X O = orange, female
X B X O = calico, female
X B Y  = black, male
X O Y  = orange, male
REMEMBER:  THE Y IS WIMPY!  No letters (genes) are attached to it.

45. X B X B (black female) x X O Y (orange male)
CROSSES
X B X B  (black female)      x     X O Y  (orange  male) 
This explains why all calico cats are female!
ALSO:  in any given cell, one of the X's becomes inactive, which randomizes the pattern or orange and black

46. COLORBLINDNESS IS ALSO SEX LINKED
Look what happens when a woman who is a CARRIER (b) marries a normal man (B)
X B X b     x      X B Y
What happens when a colorblind man marries a normal woman?
X B X B     x      X b Y

47. COLORBLIND TEST

48. Young children are given pictures instead of numbers

49. HEMOPHILIA - "bleeder's disease"
Blood will not clot normally, small injuries can be life threatening
Females can be carriers:  

50. What happens if Mom is a carrier?

52. DUCHENNE MUSCULAR DYSTROPHY
- causes progressive weakening and loss of muscle tissue
Females can be carriers:                          X D X d 

53. Checking in 3:
1.  Sex-linked genetic traits are on the _______ chromosome.
2.  Are females or males more likely to be affected by a sex-linked traits? _______
3. _________ can be carriers of sex-linked traits.
4.  What are two examples of sex-linked traits?