* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download You Light Up My Life - Lakefield District Secondary School
Survey
Document related concepts
Artificial gene synthesis wikipedia , lookup
Genome (book) wikipedia , lookup
Behavioural genetics wikipedia , lookup
Gene expression programming wikipedia , lookup
Biology and consumer behaviour wikipedia , lookup
X-inactivation wikipedia , lookup
Epigenetics of human development wikipedia , lookup
Polymorphism (biology) wikipedia , lookup
Genomic imprinting wikipedia , lookup
Epigenetics of diabetes Type 2 wikipedia , lookup
Gene expression profiling wikipedia , lookup
Hardy–Weinberg principle wikipedia , lookup
Microevolution wikipedia , lookup
Designer baby wikipedia , lookup
Sex-limited genes wikipedia , lookup
Transcript
Patterns of Inheritance Complete Dominance Incomplete Dominance Co-dominance Co-dominance with Multiple Alleles Sex Linked Impact of Mendel’s Work Mendel published his results in 1866 Paper received little notice Mendel discontinued his experiments in 1871 Paper rediscovered in 1900 Mendel’s Law of Segregation An individual inherits ONE “unit” of information (allele) about a trait from each parent During gamete formation, the alleles separate from each other (Tt T or t ) page Mendel’s Law of Independent Assortment Mendel concluded that one gene did not affect another gene Alleles for these genes separated random from each other TtRr T or t R or r so TR Tr tR tr page Complete Dominance Inheritance 2 alleles; one dominant or the other if dominant allele present, it will be expressed True-breeding homozygous recessive parent plant aa True-breeding homozygous dominant a a parent plant 2 distinct phenotypes; 3:1 ratio Aa Aa Aa Aa A Aa Aa AA A Aa Aa An F1 plant self-fertilizes and produces gametes: F2 PHENOTYPE S Aa A F1 PHENOTYPE S AA Aa Aa aa a A AA Aa a Aa aa Genetics After Mendel 1. Incomplete Dominance 2. Co-dominance 3. Co-dominance with Multiple Alleles 4. Sex Linked 1. Incomplete Dominance neither allele is completely dominant over the other X Incomplete Homozygous Homozygous parent R R parent Dominance r r All F1 are Rr heterozygous 3 phenotypes heterozygous is a “intermediate or “blend” page Rr rr Rr X Rr Rr RR F2 shows three phenotypes in 1 : 2 : 1 ratio 2.Co-dominance both alleles are expressed at the same time in the heterozygous (roan) 3 phenotypes; 1 : 2 : 1 ratio page 3. Co-dominance with Multiple Alleles: ABO Blood types Genotype Phenotype IAIA or IAi Type A IBIB or IBi Type B IAIB Type AB ii Type O 3 alleles; two that are co-dominant and one recessive IA , I B , i page ABO Blood Types type of blood determined by antigen on surface (flag) type of blood make antibodies against other antigens Blood Transfusions During transfusions recipient’s antibodies in plasma will attack blood cells that have an unfamiliar surface antigen (agglutination – clumping of blood) Type AB is universal recipient since it does not have any antibodies because it has both antigens – any blood can be donated to them! Type O is universal donor since it has neither type A nor type B antigen for antibodies to attack – give to anyone Transfusions Antibodies Can Receive Blood From A or O Type A B Type B A B or O none A, B, AB, O Type AB Type O A and B only O Rh Factor another protein marker on red blood cells independent of type of blood inheritance works according to complete dominance either Rh+ or Rh- ; Rh+ is dominant special problem during pregnancy of second child if mom is Rh- and first was baby Rh+ 4. Sex Linked genes on the sex chromosomes have different probabilities in females and males examples of recessive X linked traits – hemophilia – red/green colour blindness page Other types of Inheritance 5. Multifactorial/Multiple Genes/Polygenic 6. Sex Limited 7. Sex Influenced 8. Gene Linkage 5. Multifactorial/Multiple Genes/Polygenic Traits show wide range of phenotypic expression; continuous distribution Controlled by more than one gene Traits maybe influenced by other factors Examples human hair colour, height, eye colour, skin colour Describing Continuous Distribution Number of individuals with some value of the trait (line of bell-shaped curve indicates continuous variation in population) Range of values for the trait 6. Sex Limited Traits Expression of the trait is limited by sex of the individual Traits NOT on sex chromosome Thought to be influenced by hormones Example: heavy beards – phenotype in males only but females inherit but don’t express it but can pass trait to sons 7. Sex Influenced Traits Idea of how genes are influenced by internal environments Genes may be dominant in one sex but recessive in other; genotype interpreted differently Baldness – dominant trait in males; in females recessive trait and don’t see “bald” but rather thin Nature verse Nurture Expression of traits are not fully under control of just what your genotype is (NATURE) An organism’s internal environment and external environmental factors influence how genes may be expressed (NURTURE) Example – height – may have genetics to be tall but if there is hormonal imbalance or nutritional deficiency than won’t reach genetic potential Temperature Effects on Phenotype Rabbit is homozygous for an allele that specifies a heat-sensitive version of an enzyme in melaninproducing pathway Melanin is produced in cooler areas of body Environmental Effects on Plant Phenotype Hydrangea macrophylla Action of gene responsible for floral color is influenced by soil acidity Flower color ranges from pink to blue