MT 6 Notes Flashcards
if present, allele will always have that trait if expressed
Dominant
allele will ONLY have that trait expressed when dominant allele is not present
Recessive
2 of the same alleles
Homozygous
2 different alleles
Heterozygous
a dominant (strong) allele will express itself over a recessive (weak) allele
Law of Dominance
-the assortment of chromosomes for one trait doesn’t affect the assortment of chromosomes for another trait
-this allows for any combination of maternal and paternal chromosomes to be passed on because homologous chromosomes line up randomly during metaphase
Law of Independent Assortment
when chromosomes separate in meiosis, each gamete will receive only one chromosome from each pair
Law of Segregation
the actual alleles inherited
Genotype
the physical traits/characteristics seen in an organism
Phenotype
different versions of the same gene
Alleles
males and females have the same chromosomes for 1-22. Although, last pair are different
Sex-Linked trait
a chart used to trace the phenotypes
Pedigree
any change in DNA (the order of nucleotide bases)
Mutation
happens during DNA replication and cause a change to the original DNA sequence, happen during mutation
Gene Mutation
changes in the number or structure of chromosomes
Chromosomal Mutation
pieces of non-homologous chromosomes exchange segments (during crossing over)
Translocation
chromosomes do not separate correctly during anaphase, resulting in 1 or 3 chromosomes rather than 2 per cell
Nondisjunction
What are some causes of mutation?
-mistakes made during DNA replication, mitosis, meiosis, or protein synthesis
-mutagens
-viruses
occur in somatic cells and are passed on by mitosis to cancer
somatic mutations
occur in germ line cells that give rise to gametes and are passed on by meiosis to mutated offspring
germ line mutations
substitute one nucleotide for another, often caused by replication errors or environmental mutagens
point mutations
the insertion or deletion of a nucleotide
frameshift mutations
What sex chromosomes does a male have?
XY
What sex chromosomes does a female have?
XX
Can males be carriers?
no
linked genes
Who is more likely to have a sex linked trait?
Males, because they either have it or they don’t
having more than two alleles for one gene
multiple alleles
the heterozygous phenotype is somewhere between the two homozygous phenotypes
incomplete dominance
both traits are fully and separately expressed
Ex. Blood type
co-dominance
a trait produced by 2 or more genes
-usually shows a range in phenotype
polygenic inheritance
