You cannot repeat a characteristic once it has been used.
For example:
Incomplete dominance
Sickle cell anemia in this genetic disorder, both alleles must be normal/dominant in order for the offspring to exhibit the wild type genotype. Individual who are homozygous recessive fail to make the proper structural hemoglobin required to carry oxygen within the RBC, individuals who are heterozygous make both sickle shaped RBCs and wild type RBCs, but the sickle shaped RBCs have little effect because they are out numbered by the wild type RBCs.
Incomplete dominance is a type of inheritance in which one allele for a specific trait is not completely dominant over the other allele. This results in a combined phenotype (expressed physical trait).For example, if you cross pollinate red and white snapdragon plants, the dominant allele that produces the red color is not completely dominant over the recessive allele that produces the white color. The resulting offspring are pink. Complete dominance is A kind of dominance where in the dominant allele completely masks the effect of the recessive allele in heterozygous condition For instance, an individual carrying two alleles that are both dominant (e.g. AA), the trait that they represent will be expressed. But if the individual carries two alleles in a manner that one is dominant and the other one is recessive, (e.g. Aa), the dominant allele will be expressed while the recessive allele will be suppressed. Hence, the heterozygote (Aa) will have the same phenotype as that of the dominant homozygote (AA). This condition is called complete dominance.I tried to paste a picture but for some reason it will not post.http://biology.about.com/b/2007/09/29/what-is-incomplete-dominance.htm
ReplyDeleteIncomplete Dominance ~ If the two alleles have an incomplete dominance, then the phenotype of the heterozygote will be intermediate between the phenotypes of the two homozygotes.An example of this would be a Calico cat. This happens in female cats where the father may give an X chromosome that is for orange fur and the female may give an X chromosome for black fur. Their will be no complete dominance. Both fur colors will show.
ReplyDeleteComplete dominance is when one allele is completely dominant over the other allele, and their are no intermediate phenotypes. An example would be eye color. If someone has brown eyes, BB or Bb, and they have a child with someone that has blue eyes, bb, there will be no intermediate eye color if the B is matched with b. BB will be brown, Bb will be brown, bb will be blue.
In codominance, neither phenotype is recessive. Instead, the heterozygous individual expresses both phenotypes. A common example is the ABO blood group system. The gene for blood types has three alleles: A, B, and i. i causes O type and is recessive to both A and B. The A and B alleles are codominant with each other. When a person has both an A and a B allele, the person has type AB blood
Incomplete dominance is when the phenotype of heterozygous is intermediate between the phenotype of individuals homozygous for either allele. An example would be when white horses are crossed with brown horses.(e.g. WW) (e.g BB). When the phenotypes are crossed, the possibilities phenotypes are WW or BB.
ReplyDelete-Here is the picture below:
http://video.ecb.org/badger/download/vlc/images/VLC092_Incomplete_dominance_of_horses.jpg
Complete dominance is when phenotypes of the heterozygous and dominant homozygote are indistinguishable. An example would be when the white an brown horse crossed, thus forming a phenotype of WB. The W would be dominant, while B is recessive. The baby horse would be white when its born.
Codominance is when both alleles affect the phenotype in seperate. An example would be human MN blood is determined by two dominant alleles. M allele has red blood cells with only M molecules, while N allele has red blood cells with only N molecules. This phenotype is not intermediate between M and N.