MT 6 Biology Flashcards
Dominant
The trait that is more likely to be expressed
Genotype
the genetic makeup of an orgnanism, the letters
Allele
different versions of the same gene
Dominant
The trait that is most likely expressed; will mask the recessive trait
Recessive
The less likely expressed trait; will only show in the absence of a dominant trait
Homozygous
having two identical alleles (aa or AA)
Heterozygous
having two different alleles (Aa)
A Law of Dominance
A dominant allele will express itself over a recessive allele
Law of Independent Assortment
The assortment of chromosomes for one trait does NOT affect the assortment of another traits chromosomes
Law of Segregation
when chromosomes separate in meiosis each gamete (egg or sperm) will receive only ONE chromosome from each pair
Genotype
he genetic makeup of an organism; the letters (aa, AA, Aa)
Phenotype
the PHYSICAL trait expressed; tall, short, blonde, brunette
Allele
An allele is a variant form of a gene that controls a specific trait or characteristic
Sex linked trait
genes on the sex chromosomes
Pedigree
a chart used to trace the phenotypes and genotypes in a family to determine whether people carry diseases or traits
Mutation
a change in DNA
Somatic mutation
mutation in somatic cells; passed in my mitosis –> cancer
Germ line mutation
occur in germ line cells (that give rise to gametes) and are passed on by meiosis –> mutated offspring
Point mutation
substitutes one nucleotide for another
Frameshift mutations
the intention or deletion of a nucleotide
Translocation (chromosomal mutation)
pieces of non-homologous (chromosomes NOT coding for the name trait) exchange segments during crossing over
Nondisjunction (chromosomal mutation)
Chromosomes do not separate correctly during anaphase, resulting in 1 or 3 chromosomes per cell rather than 2
Linked genes
Genes that are physically located on the same chromosome will be inherited together ex. blonde hair and blue eyes, red hair and freckles
Multiple alleles
Having more than two alleles for one gene ex. blood type or fur color in rabbits
Incomplete dominance
The heterozygous phenotype is somewhere in between the two homozygous phenotypes
Codominance
Both traits and FULLY and SEPARATELY expressed ex. blood type
Polygenic Inheritance
A trait produced by 2+ genes ex. skin color, eye color, height, personality
