1.6 cell division Flashcards
where does each chromosome + its partner come from?
one from each parent
how many pairs of chromosomes do humans have?
23
which cells are diploid and which are haploid?
body (somatic) cells = diploid
sex cells (gametes (sperm, egg)) = haploid
cell cycle
a series of events that a cell goes through. includes growth, DNA replication, cell division, and the creation of two genetically identical daughter cells
2 phases of the cell cycle
interphase and mitotic phase
interphase
parts of the cell cycle where the cell is not dividing. the majority of the time the cell is in this phase
events that happen during interphase
metabolic reactions, protein synthesis, organelles increase in number (ex: centrioles replicate), DNA replication
how long are human chromosomes?
17mm to 80mm, must be supercoiled to fit in nucleus
which protein helps DNA coil itself in eukaryotes?
histones
what happens in prophase? (4 parts)
- DNA supercoils and becomes condense
- nuclear membrane breaks down and disappears
- 2 centrioles move to the poles of the cell
- microtubule spindle fibers connect to the centrioles
what happens in metaphase? (2 parts)
- microtubules extend from the centrioles and attach to the centromere of the sister chromatids
- chromosomes are lined up along the center of the cell
what happens in anaphase? (2 parts)
- sister chromatids are separated and travel towards poles (microtubules contract)
- centromere divides
what happens in telophase? (2 parts)
- chromosomes arrive at the poles + decondense / uncoil
- nuclear membrane reforms
mitosis
division of the nucleus
cytokinesis
division of cytoplasm and cell, occurs at the same time as telophase