DNA Test 2 8.3 Flashcards
Gene
A gene is a hereditary material passed from parents to their children. That codes for a trait.
What is DNA, and why is it called the “blueprint of life”?
It’s called the blueprint of life because it holds all of the genetic information.
Allele
An allele is two or more forms of different genes that cause a mutation. A spot on the chromosome that codes for a trait.
Chromosome
A chromosome is a structure of nucleic acids and protein that can easily be found in the nucleus, also made up of genes. a structure that holds genes. Material that codes for traits in the nucleus.
Genotype
This is the genetic constitution of an organism. Letters that represent alleles that represent the traits on the chromosome. Ex: Tt, TT, tt
Phenotype
The characteristics or traits in an individual that can be seen based on the expression of their genes. Can be seen. What is made by the genotype.
Ex: Blue eyes, black hair
Heterozygous
This is having two or more different alleles of a gene. hetero means different. Different letters that represent a trait. EX: Tt
Homozygous
This is having two or more identical alleles or a gene. Homo means the same. Same letters that represent a trait. EX: TT or tt.
Dominance
This is the trait that is passed directly from parent to child and in turn carries with it their own trait. More than likely to be shown in a person’s physical being such as baldness or tongue rolling.
Recessive
Recessive traits are traits that are carried and passed down from parent to child, but the trait may not be shown or present in the child. Both alleles must be recessive. Least likely to be shown because they are weak such as tongue rolling. 19 cannot move their ears, 4 can.
Law of Independent Assortment
alleles segregate randomly into gametes: When gametes are formed, each allele of one parent segregates randomly into the gametes, such that half of the parent’s gametes carry each allele.
The alleles of two (or more) different genes get sorted into gametes independently of one another
Law of Segregation
Only one of the two gene copies present in an organism is distributed to each gamete (egg or sperm cell) that it makes, and the allocation of the gene copies is random. Different from each other.
Co-dominance
An inheritance in which two different alleles of the same gene are shown differently and give different traits to an individual.
Horses: RR = Brown, rr = white, Rr = 1 hair is brown and the other is white (from afar it looks tan), when it’s heterozygous, both phenotypes can be seen.
Incomplete dominance
This is a form of gene interaction which happens when both alleles of a gene are partially expressed. Blending of dominant and recessive traits. Take a dominant homozygous trait. There is an average.
Rose red - RR (one from mom and the other from dad). The rose color is phenotype and the RR is the genotype.
White rose rr because it’s recessive. White is phenotype and homozygous. rr is genotype. Pink is Rr. Heterozygous.
X-linked trait
Traits that are influenced by genes on the X-chromosome. 1-22 Autosomes (everyone has). 1 = biggest, 20 = smallest. 23 sexchromosomes. XX = Female.
Y-linked trait
Traits that are influenced by genes on the Y-chromosome. Only expressed in males. Usually considered male type traits.
Polygenic inheritance
This is a characteristic or trait that defines someone physically such as height or hair color with many dominant alleles. It is dependant upon how many dominant traits are on the chromosome for a trait.
Multiple alleles
The term multiple alleles the alternative forms of the same gene so they influence the same trait.
When you only see three traits: ex: curly, wavy or straight hair, what can it be?
Either incomplete dominance or codominance
