multiple alleles genetics unit biology 30 mrs. s. pipke-painchaud
Post on 28-Dec-2015
221 Views
Preview:
TRANSCRIPT
Multiple Alleles
• have 3 or more alleles for the same gene (or at a single locus)
• In Other Words – there are 3 or more alleles that create the different traits.
• at most one individual will have 2 alleles or 1 pair (unit factors exist in pairs.)
• in a species, however, many alternative forms exist
Example – ABO Blood Group
• this deals with the presence of antigens– These are like labels/ name tags on the blood
cells.
• Each individual has 1 of 4 phenotypes – Type A– Type B– Type AB– Type O
– What are you?
http://www.rrsd.mb.ca/ResourcesandProjects/grade8/images/red%20blood%20cells.jpg
The Info You Need To Know• Gene designated is I (isoagglutinogen)
– I = A antigen – I = B antigen– i = no antigen
• IA and IB are both codominant
• IA and IB are both dominant to I (type O)
Genotype Antigen Phenotype
IAIA A A
IAi A A
IBIB B B
IBi B B
IAIB AB AB
i i Neither O
• http://learn.genetics.utah.edu/units/basics/blood/types.cfm
Website Resoures• Nobel Prize – Blood Typing Website:
– http://nobelprize.org/educational_games/medicine/landsteiner/readmore.html
– View for animations and background info on blood types.
• Wikipedia – Blood Types– http://en.wikipedia.org/wiki/Blood_type– Contains a chart of blood types by nation.
• Maps of the Distribution of Human Blood Types all over the World.– http://anthro.palomar.edu/vary/vary_3.htm
• Sickle Cell Anemia Example:– http://www.astrographics.com/GalleryPrintsIndex/GP2146.html
Did You Know?• B is the rarest allele. • 16% of the population have it.
– Distribution of Blood Types • http://anthro.palomar.edu/vary/vary_3.htm
http://www.faqs.org/health/images/uchr_01_img0015.jpg
http://www.uwosh.edu/med_tech/teaching/ElementaryHemeWeb/LEARN%20ABOUT%20RBCS%20AND%20PLTS.htm
• Wikipedia: http://en.wikipedia.org/wiki/Image:ABO_blood_type.svg
Practice
• If a person with Type A (Heterozygous) blood married and had children with a person who has Type B (Heterozygous) blood, what would the genotypic and phenotypic ratios be?– IAi X IBi
IA i
IB IAIB IBi
i IAi ii
Genotypic Ratio:
1 IAIB : 1 IAi: 1 IBi: 1 ii
Phenotypic Ratio:
1 AB: 1 A: 1 B: 1 O
Practice
• If you crossed a person with type 0 with heterozygous type B, what would the phenotypic ratio be?– ii X IBi – Phenotypic Ratio:
• 1 B : 1 O
i i
IB IBi IBi
i ii ii
Website Resoures• Nobel Prize – Blood Typing Website:
– http://nobelprize.org/educational_games/medicine/landsteiner/readmore.html
– View for animations and background info on blood types.
top related