1 / 13

KEY CONCEPT Phenotype is affected by many different factors.

KEY CONCEPT Phenotype is affected by many different factors. In (3.)incomplete dominance , (AKA- intermediate dominance) neither allele is completely dominant nor completely recessive. Heterozygous phenotype is intermediate between the two homozygous phenotypes

conlan
Download Presentation

KEY CONCEPT Phenotype is affected by many different factors.

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. KEY CONCEPT Phenotype is affected by many different factors.

  2. In (3.)incomplete dominance, (AKA- intermediate dominance) neither allele is completely dominant nor completely recessive. • Heterozygous phenotype is intermediate between the two homozygous phenotypes • Use capital letters and apostrophes’ • RR-red homozygous dominant • RR’-pink heterozygote is intermediate • R’R’-white homozygous recessive

  3. Phenotype can depend on interactions of alleles. • In (3.)incomplete dominance, neither allele is completely dominant nor completely recessive. • Heterozygous phenotype is intermediate between the two homozygous phenotypes • Homozygous parental phenotypes not seen in F1 offspring • B1B1 GreenB2B2 blueB1B2 royal blue

  4. Codominant alleles are neither dominant nor recessive. • Ex. The ABO blood types result from codominant alleles. • Ex. Sickle cell disorder • RR- normal red blood cell shape • RS-sickle cell trait- carrier • SS-sickle cell anemia • (4)Codominant –equal expression of both alleles.

  5. Genetic disorder- • Hemoglobin- a protein in Red Blood Cells that carry oxygen to body cells • Sickle cell anemia-a genetic disorder that causes a change in the shape of red blood cells • Sickle cell Trait-some normal, some sickle shaped cells

  6. (5) multiple alleles • Traits that are controlled by more than 2 alleles, although only two alleles exist in a diploid cell. • Example- Human Blood Types-each person inherits two alleles, one from each parent, but three exist in the human “gene pool”. 4 blood types3 alleles • Type-A IAIA, IAi A is dom. to O • Type-B IBIB, IBi B is dom. To O • Type-AB IAIB AB are codominant • Type-O ii recessive • This is determined by the shape of proteins on red blood cells and by the presence or absence of plasma antigens. O universal donor-AB universal receiver.

  7. Order of dominance: brown > green > blue. (6)Polygenic -many genes may interact to produce one trait. The genes may be on the same or on a different chromosome.Result in a wide rangeof variation.Ex. Hair color, height eye color

  8. Often compared to a bell curve • AA,BB,CC highest range • aa.bb.cc lowest range • Aa,Bb,Cc middle

  9. An (7)epistatic gene can interfere with other genes.

  10. Other factors of gene expression Phenotype is a combination of genotype and environment. • External environment- • temperature, nutrition, • light • Internal factors: different • hormones, structures, and • effects of aging. Ex.The sex of sea turtles depends on both genes and the environment-(temperature of the nest) • Ex.Height is an example of a phenotype strongly affected by the environment.

More Related