16.1 the cell cycle Flashcards
3 points of cell theory
1- all living things are composed of cells
2- cells are the basic unit of life
3- all new cells arise from pre-existing cells
3 reasons why cells divide
1- maintain a large SA/V ratio
2- replace old cells
3- growth
2 types of cells that make up the human body
gametes and somatic cells
gametes divide via______
meiosis
somatic cells divide via____
mitosis
what is a polyploid
when organisms have more then 2 of each chromosome (eg= triploid, tetraploid etc)
daughter cells contain the same cells as
parent cells
when dividing, strands of DNA are organized into _____
chromosomes
when DNA isn’t dividing, chromosomes extend into long strands called ___
chromatin
when the cell is preparing to divide DNA is ____ and wraps around ____ called ____
condensed, proteins, histones
each homologous chromosome _____ before cell division
replicates
chromosomes replicating leads to _______ _____ _____
identical sister chromatids
sister chromatids join at the ___
centromere
homologous chromosomes contain the same order of genes but not ___
identical copies of each gene
alleles=
different forms of the same gene (eg blue an brown eyes)
homologous chromosomes are paired based on what 3 things
length, banding pattern and location of centromere
2 main stages of the cell cycle
interphase and cell division
what happens during interphase
cells prepare for the next division
3 phases in interphase
1- growth phase (G1)
2- synthesis phase (S)-
3- Growth phase (G2)
what happens in the G1 phase of interphase
rapid cell growth, nearly half of cell cycle
what happens in the S phase of interphase
sister chromatids are produced through DNA synthesis and replication
what happens in the G2 phase of interphase
replenish energy, final prep for cell division
interphase ends when ___ begins
divisions (mitosis)
2 main processes of cell division
1- mitosis
2- cytokinesis
what happens during mitosis
division and separation of nuclear contents
what happens during cytokinesis
division of cytoplasm and its components into 2 separate cells
result of cell division
two new daughter cells are formed with identical genetic info
