Chromosomal Basis of Hereditary Flashcards
packed coils of DNA and protein
nucleosome
Where are the chromosomes in prokaryote found
nucleoid region
control protein synthesis thereby influencing traits
Genes
end part of the chromosome
telomere
sequence of telomere
TTAGGG (500-3000 times)
maintains the TTAGGG sequence
telomerases
telomere shortens every __?
cell division
Four (4) types of chromosomes based on centromeric positions
- Metacentric
- Submetacentric
- Acrocentric
- Telocentric
when primary constriction divides the arms equally
metacentric
short arm, long arm
submetacentric
- has a satellite
- very unequal arms
- has secondary constriction
acrocentric
what is the satellite used for
barcoding, molecular profiling of species
- centromere is found at the end of the chromosome
telocentric
short arm
p
long arm
q
Number of Chromosomes
- constant for each cell in the body (except sex cells = half sets)
- constant throughout the life of an organism
- constant for all members of a species
how long does mitosis last
in 16 hours, only 1 hour is spent in mitosis
phase when cells do not divide
G0
Meiosis difference in mitosis
- synapsis
- crossing-over
- metaphase 1 chromosomes align by pair
Substages of Prophase I
- Leptotene
- Zygotene
- Pachytene
- Diplotene
- Diakinesis
chromatins condense
leptotene stage (leptonema)
- synapsis occur
- synaptonemal complex appears
- homologous align along their entire length
zygotene stage (zygonema)
- where chromosomes thicken and shorten
- homologous recombination happens because of crossing-over
pachytene stage (pachynema)
- characterized by desynapsis
- chiasmata formation
- synaptonemal complex dissolve
- separation start except at the site of crossing-over
diplotene stage (diplonema)
- end stage
- chiasmata terminalization
- bivalent are being distributed evenly in the nucleus
- breakdown of nuclear membrane
diakinesis
female (XX)
homogametic
male (XY)
heterogametic
chromosomes that are not sex chromosomes
autosome
