1. Non-Mendelian Genetics (Non-Mendelian Patterns of Inheritance) -Incomplete dominance -Codominance -Sex determination -Sex-linked traits Roel R. Maraya BEEdBSEd 4-1 (Natural Sciences) January 19, 2010
2. Answer this!?
A homozygous round seed crosses with a homozygous wrinkled seed. Give the genotype and the phenotype of the offspring.
What if you marry an American man o woman? What do you think would be your children look like?
Think! Think! Think!
4. Non-Mendenlian Inheritance
is a general term that refers to any pattern of inheritance in which traits do not segregate in accordance with Mendels laws.
5. Incomplete Dominance
is a form of intermediate inheritance in which one allele for a specific trait is not dominant over the other allele.
With incomplete dominance , a cross between organisms with two different phenotypes produces offspring with a third phenotype that is a blending of the parental traits.
the "recessive" & "dominant" traits appear together in the phenotype of hybrid organisms.
Both alleles contribute to the phenotype of the organism by showing up simultaneously (at the same time) in heterozygous individuals.
9. Example R = allele for red flowers W = allele for white flowers red x white ---> pink RR x WW ---> 100% RW
With codominance , a cross between organisms with two different phenotypes produces offspring with a third phenotype in which both of the parental traits appear together .
11. Sex Chromosomes
- have non-identical sex chromosomes (XY).
- have identical sex chromosomes (XX).
12. Sex Determination
13. Sex-linked traits
This is also referred to as x-linked traits.
These are determined by genes that are carried on the X chromosomes.
This is determined also in the sex chromosomes of an individual.
14. Genotypes and Phenotypes of Color Blindness in Humans Color-blind male 5. X c Y Normal male 4. XY Color-blind female 3. X c X c Normal female,carrier of the gene 2. XX c Normal female 1. XX Phenotypes Genotypes
15. Sex-linked trait
16. Sex-influenced traits
The traits produced here is not sex-linked, but is carried by the body chromosomes or AUTOSOMES.
Example of this is Baldness.
17. Assignment # 1
Directions: Answer the following questions. Write your answers on a short bond paper. COPY and ANSWER.
1. Suppose a heterozygous woman (genotype X c X) marries a color blind man (genotype X c Y), determine the phenotypes of their children using a Punnett square.
2. Suppose a color-blind woman (X c X c ) th a normal marries a man with a normal vision (XY), determine the phenotypes of their children using a Punnett square.