1. Mendelian Genetics

2. Inheritance, or heredity passing traits to the next generation
Chapter 10
Sexual Reproduction and Genetics
10.2 Mendelian Genetics
How Genetics Began
Inheritance, or heredity passing traits to the next generation
Mendel performed cross-pollination in pea plants.
Mendel followed various traits in the pea plants he bred.

3. The parent generation is also known as the P generation.
Chapter 10
Sexual Reproduction and Genetics
10.2 Mendelian Genetics
The parent generation is also known as the P generation.

4. The second filial (F2) generation is the offspring from the F1 cross.
Chapter 10
Sexual Reproduction and Genetics
10.2 Mendelian Genetics
The offspring of this P cross are called the first filial (F1) generation.
The second filial (F2) generation is the offspring from the F1 cross.

5. Mendel studied seven different traits.
Chapter 10
Sexual Reproduction and Genetics
10.2 Mendelian Genetics
Mendel studied seven different traits.
Seed or pea color
Flower color
Seed pod color
Seed shape or texture
Seed pod shape
Stem length
Flower position

6. An alternative form of a trait
Chapter 10
Sexual Reproduction and Genetics
10.2 Mendelian Genetics
Genes in Pairs
Allele
An alternative form of a trait
Ex. Eye color

7. Chapter 10
Sexual Reproduction and Genetics
10.2 Mendelian Genetics
Dominance
Homozygous 2 of the same alleles for a particular trait, also called pure bred.
Heterozygous 2 different alleles for a particular trait, also called hybrids. Bb bb BB

8. Genotype and Phenotype
Chapter 10
Sexual Reproduction and Genetics
10.2 Mendelian Genetics
Genotype and Phenotype
Genotype allele pairs (GENES)
TT, Tt, BB, bb, Mm
Phenotype The observable characteristic or outward expression of an allele pair (WHAT YOU SEE) Bb

9. Dominant vs. Recessive Dominant Recessive
The phenotype of the organism is determined completely by one of the alleles
Written with at least 1 capital letter (TT or Tt)
Recessive
The other allele, has no big effect on the organism's phenotype
Written with lowercase letters (bb)
Example: Brown eyes is dominant and blue eyes is recessive

10. Mendel’s Conclusions cont’d…
Ex. Tall plant (T) x short plant (t) = tall offspring (Tt)
What allele was dominant?

11. Mendel’s Law of Segregation
Chapter 10
Sexual Reproduction and Genetics
10.2 Mendelian Genetics
Mendel’s Law of Segregation
Two alleles for each trait separate during meiosis.
During fertilization, two alleles for that trait unite.

12. Chapter 10
Sexual Reproduction and Genetics
10.2 Mendelian Genetics
Monohybrid Cross
A cross that involves hybrids for a single trait is called a monohybrid cross.

13. Dihybrids are heterozygous for both traits.
Chapter 10
Sexual Reproduction and Genetics
10.2 Mendelian Genetics
Dihybrid Cross
The simultaneous inheritance of two or more traits in the same plant is a dihybrid cross.
Dihybrids are heterozygous for both traits.

14. Law of Independent Assortment
Chapter 10
Sexual Reproduction and Genetics
10.2 Mendelian Genetics
Law of Independent Assortment
Random distribution of alleles occurs during gamete formation
Genes on separate chromosomes sort independently during meiosis.
Each allele combination is equally likely to occur.
Law of Segregation
The two alleles for each trait separate during meiosis (ex: If a parent is Tt, then either T or t can be given to the offspring)

15. Predict the possible offspring of a cross between two known genotypes
Chapter 10
Sexual Reproduction and Genetics
10.2 Mendelian Genetics
Punnett Squares
Predict the possible offspring of a cross between two known genotypes

16. Monohybrid Crosses
Do this on your paper: Tt X Tt Cross: Give the genotypes, phenotypes, & percentages
Go to Section:

17. Monohybrid Cross Answer…
Go to Section:

18. Probability the chance or percentage of chance of a trait being exhibited

19. Punnett Square—Dihybrid Cross
Chapter 10
Sexual Reproduction and Genetics
10.2 Mendelian Genetics
Punnett Square—Dihybrid Cross
Four types of alleles from the male gametes and four types of alleles from the female gametes can be produced.
The resulting phenotypic ratio is 9:3:3:1.

20. Genetic Recombination
Chapter 10
Sexual Reproduction and Genetics
10.3 Gene Linkage and Polyploidy
Genetic Recombination
The new combination of genes produced by crossing over and independent assortment

21. 10.3 Gene Linkage and Polyploidy
Chapter 10
Sexual Reproduction and Genetics
10.3 Gene Linkage and Polyploidy
Gene Linkage
The linkage of genes on a chromosome results in an exception to Mendel’s law of independent assortment because linked genes usually do not segregate independently.

22. Chapter 11
Complex Inheritance and Human Heredity
11.2 Complex Patterns of Inheritance
Incomplete Dominance
The heterozygous phenotype is an intermediate phenotype between the two homozygous phenotypes.

23. Both alleles are expressed in the heterozygous condition.
Chapter 11
Complex Inheritance and Human Heredity
11.2 Complex Patterns of Inheritance
Codominance
Both alleles are expressed in the heterozygous condition.

24. Multiple alleles can demonstrate a hierarchy of dominance.
Chapter 11
Complex Inheritance and Human Heredity
11.2 Complex Patterns of Inheritance
Coat Color of Rabbits
Multiple alleles can demonstrate a hierarchy of dominance.
In rabbits, four alleles code for coat color: C, cch, ch, and c.
Option 2 (continued on the next slide)

25. Coat Color of Rabbits 11.2 Complex Patterns of Inheritance Chapter 11
Complex Inheritance and Human Heredity
11.2 Complex Patterns of Inheritance
Coat Color of Rabbits
Chinchilla
Albino
Light gray
Option 2
Dark gray
Himalayan

26. ABO blood groups have three forms of alleles.
Chapter 11
Complex Inheritance and Human Heredity
11.2 Complex Patterns of Inheritance
Multiple Alleles
Blood groups in humans
ABO blood groups have three forms of alleles.

27. Human Blood Typing
Human blood is classified according to the presence or absence of certain markers called antigens that are located on the surface of red blood cells.
If you have the A antigen, you have type A blood and antibodies against B blood.
If you have the B antigen, you have type B blood and antibodies against A blood.

28. What about O & AB?
If you don’t have either the A or B antigen, you have type O blood.
In the US, O is the most common blood type.
You have antibodies against A and B.
You are also a universal donor. (You can give blood to anyone)
If you have both the A and B antigens, you have type AB blood and this is the rarest form of blood. No antibodies against either A or B.

29. Describe sex-linked alleles
Sex-linked alleles: controlled by genes located on sex chromosomes
Usually carried on X chromosome
Since females are XX, they are usually carriers of the trait
Since males are XY, they have a higher tendency for inheritance of trait

30. A- A-, O- A+ A-, A+, O-, O+ B- B-, O- B+ B-, B+, O-, O+ AB-
Recipient’s blood type
Compatible donor’s blood type A-
A-, O- A+
A-, A+, O-, O+ B-
B-, O- B+
B-, B+, O-, O+
AB-
A-, B-, AB-, O-
AB+
A-, A+, B-, B+, AB-, AB+, O-, O+ O- O+
O-, O+

31. Polyploidy is the occurrence of one or more extra sets of all
Chapter 10
Sexual Reproduction and Genetics
10.3 Gene Linkage and Polyploidy
Polyploidy is the occurrence of one or more extra
sets of all
chromosomes
in an organism.
A triploid organism, for instance, would be designated 3n,
which means that
it has three complete sets of chromosomes.

32. Images of chromosomes stained during metaphase
Chapter 11
Complex Inheritance and Human Heredity
11.3 Chromosomes and Human Heredity
Karyotype Studies
Karyotype—micrograph in which the pairs of homologous chromosomes are arranged in decreasing size.
Images of chromosomes stained during metaphase
Chromosomes are arranged in decreasing size to produce a micrograph.

34. Chapter 10
Sexual Reproduction and Genetics
10.3 Gene Linkage and Polyploidy
Epistasis- is a gene at one location on a chromosome can affect the expression of a gene at a second location
A good example of epistasis is the genetic interactions that produce coat color in horses and other mammals. In horses, brown coat color (B) is dominant over tan (b). Gene expression is dependent on a second gene that controls the deposition of pigment in hair.

35. Genetics Disorders

36. Recessive

37. Cystic Fibrosis
Affects the mucus-producing glands, digestive enzymes, and sweat glands

38. Albinism Caused by altered genes, resulting
in the absence of the skin pigment
melanin in hair and eyes
White Hair
Very pale skin
Pink Pupils

39. Tay-Sachs
Causes inflating of brain nerve cells and mental deterioration.
Most common in Jewish descent people

40. Dominant

41. Huntington’s Disease
Decline in nervous system functions & causes mental retardation
Ability to move deteriorates

42. Achondroplasia
small body size and limbs that are comparatively short

43. Sex-Linked (On X Chromosome)

44. Describe sex-linked alleles
Sex-linked alleles: controlled by genes located on sex chromosomes
Usually carried on X chromosome
Since females are XX, they are usually carriers of the trait
Since males are XY, they have a higher tendency for inheritance of trait

45. Hemophilia

46. Red-Green Color-Blindness

47. Co-Dominant

48. Sickle Cell Anemia Changes in hemoglobin cause red blood cells to
change to a sickle shape.

49. Non-Disjunction

50. Klinefelter Syndrome Male Extra X-chromosome Genotype: XXY Sterile
Often mentally retarded
Small testes, enlarged breasts, and reduced sperm production

51. Turner Syndrome Only one sex chromosome (an X). X__ Female Short
Fails to develop ovaries so become infertile

52. Down Syndrome

53. Chapter 11
Complex Inheritance and Human Heredity
11.1 Basic Patterns of Human Inheritance
Pedigrees
A diagram that traces the inheritance of a particular trait through several generations

54. Interpret pedigrees Pedigrees: graphic representation of family tree
Symbols identify sex, if they are carriers, if they have a certain trait, etc.
Follows one trait
May be used if testcross cannot be made

55. Pedigree Symbols

56. Hemophilia Pedigree

57. Images of chromosomes stained during metaphase
Chapter 11
Complex Inheritance and Human Heredity
11.3 Chromosomes and Human Heredity
Karyotype Studies
Karyotype—micrograph in which the pairs of homologous chromosomes are arranged in decreasing size.
Images of chromosomes stained during metaphase
Chromosomes are arranged in decreasing size to produce a micrograph.