Ch. 6.4 Polygenetic Inheritance Flashcards
What is continuous variation?
Traits showing range of small differences when multiple genes act together
What is polygenic inheritance?
Type of inheritance where multiple genes play a role in determining one trait, such as height
What is pleiotropic inheritance?
Type of inheritance when one single gene cause multiple phenotypes, such as Cystic fibrosis
What are the examples of polygenic inheritance?
Height, skin colour, weight, most diseases
What is incomplete dominance?
When alleles produce heterozygous phenotype that is intermediate between parents, such as pink flower from red and white genotypes
What is codominance?
When alleles are both expressed as phenotypes, such as red and white flower from red and white genotypes
What are antigen and antibodies for ABO types?
Type A has A antigen and B antibodies(rejects)
Type B has B antigen and A antibodies
Type AB has AB antigen and no antibodies
Type O has no antigen and AB antibodies
What is Epitasis?
One gene being dependent on the presence of one or more ‘modifier genes’
It occurs when phenotype of one gene masks phenotype of another gene
What are Epistatic mutations?
Epistatic mutations have different effects in combination than each genes
What are environmental factors?
Degree to which alleles are expressed depends on the environment
Determine its sex for chromosome xx and chromosome xy
XX is female and XY is male
What is X-Linked?
Trait determined by a gene on the sex chromosome is X-Linked (Sex-Linked in other word)
What are X-Linked genes in humans
Colour blindness, hemophilia, Duchene muscular dystrophy
What is Linkage
Tendency of genes located together on chromosome to segregate
When do genes on chromosome more likely cross over?
When they are further from each other
