Chapter 2 Flashcards
How are called identical twins?
Monozygotic
How are called non-identical twins?
Dizygotic
How are identical twins conceived?
1 ovum fertilized - 1 zygote - 2 cells clusters - 2 individuals sharing 100% of DNA
How are non-identical twins conceived?
2 ovum fertilized - 2 zygotes - 2 individual sharing 50% of their DNA
What is recessive inheritance?
need to have 2 recessive alleles to get the trait
What is dominant inheritance?
only one dominant allele necessary to get the trait
What is autosomal recessive inheritance?
disease (condition) transmitted through recessive genes; cannot be expressed if the person has not 2 recessive alleles for the trait (for non-sex cells)
What is autosomal dominant inheritance?
dominant gene carries the disease (need to have 2 recessive in order not to be sick) (non-sex cells)
What is x-linked recessive inheritance?
Disease is on the X chromosome and is recessive (BUT if you have only 1 x then you are carrier) (gametes)
What is x-linked dominant inheritance?
disease is on the X chromosome and is dominant (gametes)
What is incomplete dominance?
pattern of inheritance in which 2 alleles are expressed in the phenotype (ex: white + red flower = pink flower)
What is the diathesis in the diathesis-stress model?
Inherited tendencies, from multiple genes, to express certain traits
What is the stress in the diathesis-stress model?
These tendencies may be activates under conditions of stress
What is the diathesis-stress model?
Life events (stressor) + diathesis (genetic predisposition) make a certain condition appear (ex: alcoholism)
What is the gene-environment correlation?
There is an association between an individual’s genetic propensities and the environmental niche that the individual selects
