genetics test Flashcards
The study of heredity, how traits (characteristics) are passed down from one generation to the next
Genetics
sequence of DNA that codes for a protein & thus determines a trait
Gene
A picture or display of all the pairs of chromosomes in numerical order based on size & shape
Karyotype
Chromosomes that pair up and have the same genes, are the same size and shape.
One from mother & one from father.
Homologous chromosomes
Contain genes for all traits except for sex
Chromosome pairs 1-22
Autosome
Chromosome pair #23
XX – 2X’s will make female
XY – will make male
Sex Chromosomes
Different forms of the same gene for a specific trait.
Ex. Trait – eye color
Alleles – blue, brown, green
Alleles
An allele expressed with another recessive.
Written as a small letter.
Recessive
An allele that is expressed over a recessive
Written as a capital letter
Dominant
Outward (physical) appearance of the alleles
Ex. Blue eyes, tallness, being colorblind
Lots of misconceptions about dominant & recessive
Phenotype
The genetic makeup (gene combination) of an organism
Genotype
Having 2 identical alleles for a specific trait
Purebred
Can be dominant or recessive
Homozygous
Having 2 different alleles for a specific trait
Hybrid or carrier
Heterozygous
Two different alleles of the same trait are fully expressed Ex: Human blood types - A, B, AB, O Alleles: IA, IB, i IA & IB - i - recessive (ii=type O blood)
Codominance
Two different alleles of same trait combine (BLEND) to form a new expression of alleles
Ex: Colors in flowers, red + whitepink
Incomplete Dominance
