BIO152H5 Lecture Notes - Lecture 8: Haemophilia, Mutation, Psychoacoustics
53 views1 pages
Document Summary
Incomplete dominance: heterozygotes that have an incomplete phenotype, neither of the alleles is completely dominant from the other. The effect of pigments that are not present in a dominant-recessive type of relationship. Codominance: information from both alleles and they are both expressed. Pleiotropic effects: a single gene that influences a number of different genetic traits. If (cid:455)ou"re (cid:373)issi(cid:374)g o(cid:374)e ge(cid:374)e, the phe(cid:374)ot(cid:455)pe wo(cid:374)"t be e(cid:454)pressed as there needs to be an interaction between both the genes that contribute to the phenotype. The ratio is different from mendalian genetics and has masking effects. Quantitative (or polygenic inheritance): action of many genes which contribute to the overall effect. Environment plays a role in this type of inheritance. A continuous expression of colour that is expressed in the genotype that gives them the phenotype. A pattern of inheritance that looks like blending. The gene is on the x chromosome. Pedigrees are used to trace back genetic disorders.
Get access
Grade+
$40 USD/m
Billed monthly
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
10 Verified Answers
Class+
$30 USD/m
Billed monthly
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
7 Verified Answers
Related textbook solutions
Related Documents
Related Questions
These all relate to exceptions to the inheritance patterns encountered by Mendel.â
Why do multiple and lethal alleles often result in modifications of the classic Mendelian monohybrid and dihybrid ratios?
Select the four correct statements.
-When an essential gene is mutated, it can result in a lethal phenotype. There are no classic Mendelian monohybrid and dihybrid ratios. |
-In the case of codominance, heterozygotes produce gene products from both alleles of a gene. Classic Mendelian monohybrid and dihybrid ratios are modified by codominance. |
-In the case of incomplete dominance, the phenotype of the heterozygote is distinct from and often intermediate to the phenotypes of homozygous individuals. Classic Mendelian monohybrid and dihybrid ratios are modified by incomplete dominance. |
-Genes exist in a large number of allelic versions and a diploid organism has two homologous gene loci that may be occupied by different alleles of the same gene. This can result in many different phenotypes for traits, which may not follow typical Mendelian ratios. |
-When an essential gene is mutated, it can result in a lethal phenotype. This results in a modification of classic Mendelian ratios. |
-The phenotype of the heterozygous genotype is distinct from and often intermediate to the phenotypes of the homozygous genotypes. The joint expression of both alleles in a heterozygote is called codominance. There are no classic Mendelian monohybrid and dihybrid ratios. |
-Genes exist in a large number of allelic versions, but in a diploid organism, only one allele of the gene can occupy one homologous gene loci. Classic Mendelian inheritance cannot explain this phenomenon. |
-Each gene produces a unique gene product. The effect of one allele in a heterozygote completely masks the effect of the other. Classic Mendelian genetics cannot explain this phenomenon. |