Genetics, Heredity, Evolution, Etc Flashcards
Define mutations
Any change in DNA that may result in a new phenotype
What is human genetics
Looking at a pedigree to see how a trait is inherited over several generations
Define carrier
Someone who is heterozygous
- does not show the trait, but they can pass it to their offspring
Types of single allele trait
1) single, dominant allele
2) homozygous recessive
3) codominant allele
4) incomplete dominance
What is single, dominant allele
If you have the dominant allele, you have the trait
- huntingtons recessive
What is meant by homozygous recessive
You need 2 recessive allele to show the trait
Your parents both had to be carriers or one had the trait and the other was a carrier
-myopia - nearsightedness
What is meant codominant allele
If you are heterozygous for this genotype, you will express both phenotype
-sickel Cell disease
What is meant by incomplete dominance
Dominant allele is not completely dominant over the recessive allele
Blending of the phenotype is seen
What is a polygenic trait
Trait that is controlled by 2 or more genes
- skin color, eye color, fur color
Examples of polygenic trait
Multiple-allele trait
Sex-linked trait
What is a multiple allele trait
3 or more alleles of the same gene code for a single trait
-blood type (ABO)
What is a sex linked trait
Genes for these traits are found on the sex chromosome
Daughters have a 50% of being a carrier
Sons have a 100% of having trait if mom has it
Always gets X from mom
-color blindness
- hemophilia
Explain the relationship between a change in the genetic code of an organism and how that change may affect the production, the type, or the effect of a certain protein
A change in the genetic code may affect the organism favorably or unfavorably. It might change a protein to a different shape and this shape might make the organism thrive in its environment, did or stay the same.
Explain how a change in a protein could have a detrimental, a neutral, or a beneficial effect on an organism.
The protein might make the organism have a new shape or color, etc and this new characteristic might kill you off, or make you thrive or not affect you at all.
Proteins changing and have mutations are the causes of what
Speciation
Explain where a Germ Cell Mutation occurs and if it affects the organism or the offspring (and why that is)
Germ cell mutation occurs in the gametes.
It does not affect the organism but if is passed to the offspring
It provides the variation on which natural selection acts
Explain where a Somatic Cell Mutation occurs and if it affects the organism or the offspring (and why that is).
Somatic cell mutation occurs in body cells
It is passed to daughter cells by Mitosis
List the four types of Chromosomal Mutations.
1- deletion
2- inversion
3- translocation
4- nondisjunction(monosomy/trisomy)
What is deletion mutation
A piece of chromosome is deleted
What is inversion mutation
A section of chromosome breaks off and reattached in the opposite direction
What is translocation mutation
A section breaks from one chromosome and attaches to another chromosome
What is nondisjunction mutation
When chromosomes pairs fail to seperate during meiosis
What are the types of nondisjunction
Monosomy & trisomy
What is monosomy mutation
When a zygote has only one chromosome of a pair
-turners syndrome
Male: 46XY
Female: 46 XX
Turner: 45X
