Chromosomes Flashcards
When are chromosomes visible
During cell division
Chromosome
Made up of genes in the nucleus of a cell
Structure
Proteins and nucleic acids
Sister chromatids
The two chromosomes that are joined together by hydrogen bonding at the centromere to make one chromosome
Formation of a chromosome
DNA strands wrapped around histone proteins that form coils and then form a supercoil
Autosome
Do not determine gender
humans have 46
each parent gives 23
Sex chromosomes
Determines gender
each human has two
and each parent gives one
(males give X or Y and females give X- having one Y makes you male)
Homologous pairs
Two 2-chromatid chromosomes that have the same types of genes (not necessarily the same versions)
The two sex chromosomes pair up even though they’re not exactly the same
Homologous formula
Xn=Y X= # of copies n= # of types Y= total # Humans: 2x23=46
Diploid
2n
Cells have two copies of each chromosome
Humans- autosomes
Haploid
N
Cells with only one copy of each chromosome type
Humans- sex chromosomes
Histone
Protein in chromosomes that DNA wraps around
Karyotype
A picture of all the chromosomes in a dividing cell
Largest to smallest
In pairs
Binary Fission
It happens in prokaryotes chromosomes are copied and divide into daughter cells it's a sexual and their complete replicas Diploid
Mitosis
eukaryotes to replace dead stomatic cells, for repair, and growth
Makes diploid cells
divides chromosomes and splits
asexual
