Topic F: Simple Inheritance Flashcards
What are the two categories of inheritance?
- simple inheritance
- complex inheritance
What is simple inheritance?
- inheritance of traits that are determined by one (or very few) genes
- qualitative traits, like eye colour in drosophila
- show discontinuous variation on bar graphs, easily able to put them into separate groups or categories.
- relatively easy to study
What is complex inheritance?
- traits determined by many genes
- can also be affected by then environment
- quantitative traits
- continuous variation, so they can not be easily put into separate groups, ex like height.
- challenging to study
Most phenotypes in multicellular eukaryotes are not determined by _________ inheritance, but ______ inheritance
Most phenotypes in multicellular eukaryotes are not determined by SIMPLE inheritance, but COMPLEX inheritance
most human medical conditions and diseases are the result of ______ ______
complex genetics
complex traits often also have _______ influences, meaning that factors such as _____ or ________ can influence whether or not a trait develops.
complex traits often also have ENVIRONMENTAL influences, meaning that factors such as DIET or EXPOSURE TO VIRAL INFECTION can influence whether or not a trait develops.
genes that determine simply inherited traits can be located on the ____________ or _______
sex chromosomes or on the autosomes
Simply inherited single gene traits exhibit one of four inheritance patterns:
- Autosomal Dominant
- Autosomal Recessive
- Sex-Linked Dominant
- Sex-Linked Recessive
the 2 types of inherited genes on autosomes
- Autosomal Dominant
- Autosomal Recessive
the 2 types of inherited genes on the sex chromosomes
- Sex-Linked Dominant
- Sex-Linked Recessive
What are autosomes?
- chromosomes that are NOT sex chromosomes
- in humans, we have 23 pairs of chromosomes total. 22 pairs are autosomal, 1 pair is sex chromosomes.
Seeing the same phenotypes and frequencies in the F1 and F2 generation of a OG cross and reciprocal cross, means that this is evidence of …..
Autosomal inheritance
If inherited traits are autosomal, and we perform a reciprocal cross, what happens?
nothing changes. F1 and F2 generations would be the same, as the trait is not sex-linked, and so swapping the genes of the parents would not change the subsequent generations.
2 importance characteristics of sex-linked inheritance;
- we do NOT observe the same phenotypes and ratios in the F1 and F2 generations of reciprocal crosses
- We observe different patterns of inheritance (phenotypes) in males vs. females
Homogametic sex is ______, while heterogametic sex is ______
Homogametic sex is female (XX), while heterogametic sex is Male (XY)