Principles Of Genetic Inheritance Flashcards
genes
are segments of DNA in a
chromosome
locus
specific place of gene on chromosome
Chromatid
is one of two identical copies of a
chromosome
centromere
connects identical sister
chromatids
telomere
is a region at the end of a
chromosome for stability
somatic cells
-diploid and differentiated
homologous chromosomes
-refer to pairs of chromosomes
autosomes
– chromosomes common in
both genders
– one from each parent (X and Y)
karyotype
Entire set of a patient’s chromosomes
-presented as single condensed or duplicated chromosome
lyonization
is called X-inactivation. The choice of which X chromosome to be inactivated is random (calico cat)
mosaicism
is a condition in which cells from a patient have different genotypes (& karyotypes)
downs syndrome
-some 46XX some 47 XX + 21
klinefelter syndrome
some 46 xy some 47 XXY
Turner syndrome
some 46 XX some 45 XO
Mitosis- interphase
chromosome duplication
mitosis- cell division
one copy of each chromosome (chromatid)
and 1⁄2 of the cytoplasm/organelles are distributed
between the two daughter cells
stem cells
undergo mitosis, but divide asymmetrically,
resulting in one stem cell, and one daughter cell
meiosis
reduces the total number of chromosomes by half, producing four gametes (haploid) -occurs in germ line cells
homologous recombination
- occurs in meiosis
- produces new combos of genes
what does meiosis consist of?
– one round of DNA replication – two rounds of nuclear divisions
in which 2 ways does meiosis create genetic diversity?
– Random segregation of homologs – Cross-over exchange (homologous recombination)
euploid
Cells with a normal number of chromosomes
polyploidy
presence of a complete set of extra chromosomes in a
cells
-often seen in plants
aneuploidy
Cells with a missing or additional individual
chromosomes
-monosmy and trisomy
how do you get aneuploidy?
non-disjunction
translocation
non homologous chromosomes exchange genetic material
reciprocal translocation
an exchange of material between nonhomologous chromosomes
- Philadelphia
chromosome
roberstsonian translocation
long arm of 2 acrocentric chromosomes combined, short arm typically lost
-leads to someone being translocation carrier
turner syndrome
45, XO karyotype female- no Y -short stature -infertile normal intelligence
