Unit 5: Topic 4 - Non-Mendelian Genetics Flashcards
What are the four types of non-Mendelian inheritance?
Codominance, incomplete dominance, multiple alleles, and polygenic traits.
What is codominance? Give an example.
Codominance is when two alleles are expressed at the same time. An example of this could be specific chickens that can express both black and white feathers simultaneously.
What is incomplete dominance? Give an example.
Incomplete dominance is when neither allele is dominant, and there is a third phenotype that is present. An example of this is if there are alleles for straight and curly hair, an offspring can contain slightly wavy hair instead.
What are multiple alleles in genetics? Give an example.
Multiple alleles are when more than two alleles are able to code a gene. An example of this is blood type. There are three different alleles that can determine your typing: A, B, and O.
What are polygenic traits? Give an example
Polygenic inheritance is when multiple genes help create a specific phenotype. An example of this is skin color which is a combination of over 150 genes.
What are the three types of sex-based inheritance?
Sex-linked, Sex-limited, and Sex-influenced
Explain what Sex-Linked traits are and give an example.
Sex-Linked traits are traits that are traits that are generally linked to one specific sex.
Generally, they are only prevalent in males who carry XY chromosomes. This is because,
in Females, the second X chromosome helps counteract the trait. An example of this would
be sickle-cell or color blindness, which commonly affects males only.
Explain what Sex-Limited traits are and give an example.
Sex-Limited traits are traits that are only visible within one sex. An example of this would be the barred pattern on roosters. Although hens can carry the genotype for the narrated pattern, they will not show the pattern.
Explain what Sex-Influenced traits are and give an example.
Sex-Influenced traits are autosomal traits that are generally influenced by sex. In males, these traits only need one recessive gene to be shown, while in females, they need 2. A common example of this is baldness, which occurs mainly in the male population.
What are some common examples of traits that are influenced by multiple genes?
Height, skin color, and certain genetic diseases such as diabetes.
Why do mitochondra and chloroplast not follow the general Mendelian rules?
Due to the nature of random assortment of organelles in the zygote during mitosis, there is the chance that some cells will contain all dominant genes, some will have a mix of dominant and recessive, and some will have all recessive genes. Mitochondira and chloroplasts do not follow these rules due to the nature and function of these organelles.
What form of inheritance do mitochondrial and chloroplast DNA follow?
Both mitochondrial and chloroplast DNA are inherited maternally, which means that all of an organism’s mitochondrial and chloroplast DNA comes from its mother.
