2.6 Patterns Of Inheritance Flashcards
What does the term “affected” mean
It’s when an individual has or shows a particular trait.
What does autosomal mean?
This refers to all chromosomes except for 23rd (sex chromosome)
What is Autosomal Inheritance?
The inheritance of traits (passing down genes) that are located on all chromosomes but the 23rd (the sex)
What is Autosomal Dominant?
The inheritance of a dominant phenotype whose gene is on an autosomal chromosome
What is Autosomal Recessive?
Example of a disorder?
It is the inheritance of a recessive phenotype who’s gene is on an autosomal chromosome (all but the 23rd)
- Ex. cystic fibrosis is an autosomal recessive trait.
What is a key indicator in a pedigree of autosomal recessive inheritance?
If the affecting trait skips generations. (Unaffected individuals can have an affected child)
What is an indicator of autosomal dominant inheritance in a pedigree?
Once a trait is no longer in the family, it will not reappear. (An affected child needs at least 1 affected parent) (unaffected: aa)
Codominance (think of it like co-dominance)
The condition where both alleles for a trait are equally expressed in a heterozygote,
- ex. If one allele is from a red flower and another from a white, the flower would be partially red and white.
What is heterozygous advantage?
It is a survival benefit for individuals get two different alleles for a certain trait.
What’s an example of heterozygous advantage?
Sickle cell anemia:
- People who are heterozygous with sickle cells have normal Blood Cells, as well as some C shaped Red Blood Cells (from anemia)
- Due to some C shaped cells, those ppl would be better protected from malaria.
What is the condition when there is more than 2 possible alleles for a certain gene?
(Give an example)
Multiple Allelism
- ex. Human blood type: 3 allele options: A,B,O
What is Incomplete Dominance?
When neither gene is dominant over the other when heterozygous.
- The genes can mix to make a hybrid (ex, white + red = pink offspring)
What is the phenotypic ratio of F2 generation incomplete dominant alleles?
1:2:1 (refer to page 1 of 2.6)
What’s the Genotype for the blood type phenotype Type A
Genotype: I^A I^A (if homo type A) or I^A i (If hetero w type O)
Which blood types are co-dominant?
Type A and B
(Thats why some people are type AB)
What is the genotype for Type O blood?
Genotype: ii
