Chromosomes & The Cell Cycle Flashcards
Prokaryote vs. eukaryote chromosomes
Prokaryote: short and circular
Eukaryote: long and linear
Prokaryote basics
no nucleus
Single celled
Always haploid
Eukaryote basics
Have a nucleus
Some single celled, some multicellular
Both haploid and diploid
Every cell has it’s own ____ and can be ___ or ___
Genes, haploid, diploid
Haploid definition
1 copy of every gene
Diploid
2 copies of every gene
1 from mom and 1 from dad
Mitosis definition
Cell division that makes 2 daughter cells identical to the mother cell–whether haploid or diploid
Meiosis definition
Cell division that splits diploid cells into haploid cells
Cell division in prokaryotes
Very simple–circular haploid chromosome of DNA duplicates, then cell splits in two
Result: 2 identical haploid daughter cells
Human diploid cell chromosome #
23 pairs, or 46 chromosomes
After DNA duplication, Human diploid cell chromosome #
23 pairs, or 46 chromosomes
BUT each chromosome has a sister chromatid = 92 chromatids in the cell
When the cell is about to divide it first…
Duplicates chromosomes
After duplication of chromosomes…
Each chromosome consists of 2 sister chromatids
What is a chromosome?
A strand of DNA that carries genetic info in a cell
Human haploid and diploid #s
Haploid (N) = 23
Diploid (2N) = 46
spindle fiber
long protein molecule (microtubule) that tows chromosomes during division
centromere
area of a chromosome where spindle fibers attach during division
kinetochore
protein structure on a centromere where spindle fibers attach