Presentation is loading. Please wait.

Presentation is loading. Please wait.

KEY CONCEPT Phenotype is affected by many different factors.

Similar presentations


Presentation on theme: "KEY CONCEPT Phenotype is affected by many different factors."— Presentation transcript:

1 KEY CONCEPT Phenotype is affected by many different factors.

2 Phenotype can depend on interactions of alleles.
In incomplete dominance, neither allele is completely dominant nor completely recessive. Heterozygous phenotype is intermediate between the two homozygous phenotypes Heterozygous is like a “blend”

3 List the genotypes. 4RW List the phenotypes. 4 Pink W W R W R W R pink
Example: Cross a homozygous red carnation flower (RR) with a homozygous white flower (WW). List the genotypes. 4RW List the phenotypes. 4 Pink W W R W R W R pink pink R W R W pink pink

4 List the genotypes. 2RW, 2WW List the phenotypes. 2 Pink, 2White R W R
Example: Cross one heterozygous pink (RW) 4 o’clock flower with a White flower (WW). List the genotypes. 2RW, 2WW List the phenotypes. 2 Pink, 2White R W R W W W W pink white R W W W pink white

5 Codominance red white roan
Defined: When both alleles are dominant and equally expressed The colors do NOT blend together, but are equally seen Ex: Cattle Coat Red cow x White cow = Roan Cow Ex: Human Blood types Type A x Type B = Type AB red white roan

6 Blood types are another example of codominance.
The ABO blood types result from codominant alleles This blood group consists of 3 different alleles Dominant A allele Dominant B allele Recessive O allele A and B are equally dominant Many genes have more than two alleles.

7 B B A A B A B A B A B List the genotypes. 4AB List the phenotypes.
Ex: Cross Jason who is homozygous for type A blood with Maria who is homozygous for type B blood. List the genotypes. 4AB List the phenotypes. 4 type AB blood B B A A B A B A B A B

8 B o A o A B A o B o o o List the genotypes. 1AB, 1Ao, 1Bo, 1oo
Ex: Cross Mike who is heterozygous for type A blood with Lisa who is heterozygous for type B blood. List the genotypes. 1AB, 1Ao, 1Bo, 1oo List the phenotypes. 1 type AB blood 1 type A blood 1 type B blood 1 type o blood Probability of Heterozygous individual? 75% B o A o A B A o B o o o

9 Many genes may interact to produce one trait.
Polygenic traits are produced by two or more genes. Order of dominance: brown > green > blue.

10 An epistatic gene can interfere with other genes.
This is like a “knock out” gene

11 The environment interacts with genotype.
Phenotype is a combination of genotype and environment. The sex of sea turtles depends on both genes and the environment Height is an example of a phenotype strongly affected by the environment.


Download ppt "KEY CONCEPT Phenotype is affected by many different factors."

Similar presentations


Ads by Google