29 terms

Chapter 15

genetics terms and the chromosomal basis of inheritance terms
chromosome theory of inheritance
a theory that states that genes have specific positions along chromosomes that undergo independent assortment
wild type
the dominant, most common phenotype
mutant phenotypes
the phenotype that is different from the wild type that us usually caused by a mutation
sex-linked gene
a gene located on a sex chromosome
y-linked gene
a gene located on the y chromosome
x-linkd genes
genes attatched to x chromosome, about 1100 of them
describes allele arrangement for males who only have one locus
Duchenne muscular dystrophy
a disease that causes weakening and loss of coordination. due to a gene that is x-linked
an x-linked recessive genetic disorder. stops blood from clotting
Barr body
the condensed body of inactive x chromosomes in females when only one half needs to be active
linked genes
genes near each other on a chromosome that are inherited together
parental types
offspring that match either of parent's phenotype
genetic recombination
offspring with different traits than their parents
recombinant types/recombinants
nonparental types with different phenotypes (shape, color)
crossing over
homologous pairs that exchange proteins between paternal and maternal chromatids
genetic map
a list of genetic locations of a chromosome. discovered by Morgan's student
linkage map
a diagram of recombination frequencies
map units
distance between genes
cytogenetic maps
a genetic map that locates genes relative to chromosomal features
when the meiotic spindle doesn't equally distribute chromosomes to daughter cells
when an abberant gamete (one affected by nondisjunction) joins a normal gamete, the daughter cells are aberrant too
when a zygote is missing a single chromosome
when a zygote has a single extra chromosome
when an organism has more than 2 chromosome sets (triploidy has 3 sets; tetraploidy has 4 sets)
a segment is erased
a sister chromatid gets another segment that is the same as one it already has. it usually comes from a deleted chromatid
rearranges a segment within a chromosome
two segments from two different nonhomologous pairs switch places
down syndrome
an aneuploid condition, where a person has an extra chromosome 21 bringing the total number of chromosomes to 47