Chapter 8.3 Flashcards
Binary Fission
Cell division that occurs in bacteria and archaea
Why is cell division in prokaryotes uncomplicated
because the genetic material in these cells consists of a singular circular Dna molecule
CHROMOSOME
Is a single molecule of DNA an it’s associated proteins. Each human cell has 23 pairs of chromosomes in every cell
How many chromosomes does every cell have
Each human cell has 23 pairs of (46 )chromosomes in every cell
How many does each gamete/ sex cell/ egg/ sperm have
23 chromosomes
The 2 packaging of DNA
- Chromosomes : DNA is packaged into 23 pairs of chromosomes in every cell. At this stage DNA is tightly wounded. And is only this way right before the cell divides
- CHROMATIN : Dna when tightly packaged is refered to as chromosome. The rest of the time Dna chromosomes are extended like threadlike strands called CHROMATIN.
When the cells are functioning normally, the DNA are loosely coiled around clusters of histones called nucleotides.
Nucleosomes
collectively refers to a stretch of DNA wrapped around 8 proteins called histones.
within the chromosomes which explains how so many dna can fit in one cell.
why are dna usually in the stage as chromatin
Allow easy access for enzymes to attach to specific sequences along the DNA.
- allow ran copies of dna
What happens to the packaging of the dna when the cell is ready to divide
The chromatin condenses becoming chromosome
what happens after the cell divides
The chromosomes returns to the chromatin packaging.
Chromatids
A replicated chromosome consists of two chromatids ( or 2 sister chromatids)
The product of replication
replicated 2 daughter chromatids
CENTROMERE
a small section od DNA and associated proteins that attaches the 2 chromatids together.
What is the relationship between chromosomes and chromatin
Chromosomes are chromatin coiled tightly on itself
How does DNA interact with histones
A stretch of DNA wraps around a cluster of eight histones to form a nucleosome
