-
Human inheritance is controlled by genes that are located on __________
Chromosomes
-
-
Trait
Refer to some aspects of the individual
-
Loci
location of the gene on a chromosome
-
Allele
alternate forms of genes, located on the loci
-
Gregor Mendel
Father of Genetics
Mendejian Genetics
Based on crosses he did with plants
-
Mendel's Model of Heredity
Number One
Inheritance is controlled by factors that exist within the individual and are passed on to offsprings
These factors are called genes
-
Mendel's Model of Heredity
Number Two
Most traits are controlled by two factors
These factors are called alleles
-
Mendel's Model of Heredity
Number Three
One factor may be dominant over the other one
Dd, DD, dd
-
Mendel's Model of Heredity
Number Four- Mendel's Law of Segregation
The individual has 2 factors for each trait but gametes only contain only one factor for each pair
FF= F & F
-
Capital Letters
dominant allele
Widow's Peak- W
-
Lowercase Letters
recessive allele
Continous hairline- w
-
Genotype
refers to the pair of genes that a individual actually has
-
Phenotype
refers to the physical characteristics that can actually be seen
-
-
-
-
Genotype- WW
Phenotype- Widow's Peak
-
Genotype- Ww
Phenotype-Widow's Peak
-
Genotype-ww
Phenotype- Continous Hairline
-
Homozygous Dominant and Homozygous Recessive=
Monohybrid
WW+ww= Ww
-
Heterozygous+Heterozygous=
Ww+Ww= WW, Ww, Ww, ww
3:1 Phenotopic ratio
-
Inheritance of Multitraits
Law of Independent Assortment
pairs of factors seperate independently of one another to form the gametes, so all possible combinations may occur
WwSs= WS, Ws, wS, ws
-
Multi-Trait Cross
Dihybrid+ Dihybrid=
9:3:3:1 Phenotopic Ratio
-
Intermediate Genes
Neither Dominant or Recessive
RR (red cow) + rr (white cow)= 1:2:1
-
Multiple Alleles
when there are more that 2 alleles for a trait
Example- Blood Types (A, B, o)
-
Blood Type
A
Type A antigens on RBCs
-
Blood Cells
B
Type B antigens on RBCs
-
Blood Cells
O
There are NO antigens on the RBCs
-
Blood Types
- 1. Each person can only have 2 of the 3 alleles
- 2. A and B are dominant over O
- 3. A and B- both are expressed in the presence of each other (Co-Dominant)
AA, Ao, BB, Bo, AB, oo
-
A-B-o Blood test used in paternity suits
- 1. Can NOT be used to determine that someone is the father
- 2. Can be used to prove that someone is NOT the father
-
Rh Factor
Name comes from Rhesus Monkey
-
Rh Positive
Rh antigens on RBCs
- Rh[+] Dominant
- Rh+Rh+ or Rh+ Rh-
-
Rh Negative
there are no Rh antigens on the RBCs
Rh[-] Recessive
Rh-Rh-
-
If Rh+ dad and Rh- mom = child A (Rh+Rh-)
mom makes anti-Rh antibodies
child B (Rh+Rh-)
mom's anti-Rh antibodies attack child B
Erthroblastosis fetalis
-
Polygenic Inheritance
- 1. 2 or more sets of genes effect the same trait
- 2. Can often result in a bell shaped curve with most individuals showing the average genotype
Examples- Eye and Hair Color
-
Eye Color
Alleles determione how much melanin is present in the iris
- aabb= Blue
- Aabb/aaBb= Green
- AaBb/AAbb/aaBB= Light Brown
- AABb/AaBB= Dark Brown
- AABB= Black
-
Eye Color
Dihybrid + Dihybrid=
- 1:16 =Blue
- 4:16 =Green
- 6:16 = L. Brown
- 4:16 = D. Brown
- 1:16= Black
|
|
