Ch. 4 - The Cell Cycle
暂无描述。系统推荐的高质量记忆内容，适合每天坚持背诵学习。
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what are the 3 stages of a bacteria cell cycle?
• B period - before replication • C period - chromosomes replicate • D period - division (after replication)
who do prokaryotic cells split?
binary fission
what is the origin of replication in binary fission?
a cite where enzymes are located in the middle of the cell that catalyze the reaction to split
what are the 4 main phases in eukaryotic cells?
G1, S, G2 and M phase
what are the 5 stages in mitosis M phase?
• prophase • pro metaphase • metaphase • anaphase • telophase
what is chromatin?
replication of DNA (chromosomes) - creates a sister chromatid
what is ploidy?
describes the set number of chromosomes -diploid (organ cells have 46) -haploid (sex cells have 23)
what is G1 phase?
carry out the functions and slightly grows
what is s phase?
where DNA replication occur
what is G2 phase?
cell growth continues and prepares for m phase
what is G0 phase?
the stage a cell spends 90-95% of its time in, it’s the resting stage and no longer in the active cell cycle
what happens in metaphase?
formed spindles attach to the kinetchores and the chromosomes align in the middle
what happens to prophase?
chromosomes condense and spindle forms in the cytoplasm
what happens in the prometaphase?
the nuclear envelope breaks down and the kinetochores form on each chromosomes
what happens in anaphase?
chromosomes are pull apart
what are the spindles made of and use to perform cell division?
microtubules and use ATP
what happens in telophase?
new nuclear envelope develops, spindles dissemble and cytoplasm begins to furrow and divide
what happens in cytokinesis?
the cytoplasm fully divides as well with the organelles
which organelles replicate?
mitochondria and chloroplast
what is a zygote?
a comination of two haploid gametes
what is a bivalent?
one pair of chromosomes in a tetrad
what is a tetrad?
association of a pair of homologies chromosomes (4 sister chromatids) that are physically held tofehea by at lead one DNA crossover
what is it called when genetic recombination happens during meiosis?
crossing over
what is the point of cross over between two chromosomes called?
chiasmata