The Cell Cycle: Cell Growth, Cell Division

Biology is the only subject in which multiplication is the same thing as division…

Why do cells divide?

  • For ______
  • ______reproduction
  • one-celled organisms
  • For ______
  • from fertilized egg to ______-celled organism
  • For ______
  • ______cells that die from normal wear & tear or from injury

Getting the Right Stuff

  • What is passed on to daughter cells?
  • exact copy of ______
  • ______
  • organelles, cytoplasm, cell membrane, enzymes
  • ______

Cell Division allows accurate replication, division and distribution of large ______

Genome

–Total ______of a ______of a particular ______

–Prokaryotic genome

•Genomes usually ______

–Eukaryotic genome

•______genomes
•organized into ______

Interphase

  • _____ of cell life cycle
  • cell doing its “everyday ______”
  • produce RNA, synthesize proteins/enzymes
  • prepares for ______if triggered

Cell Cycle

Interphase

  • Divided into 3 phases:
  • ______= 1stGap (Growth)
  • cell doing its “everyday job”
  • cell ______
  • ____ = ______
  • copies ______
  • _____ = 2ndGap (Growth)
  • prepares for ______
  • cell grows (more)
  • produces organelles,proteins, membranes
  • Nucleus ______
  • DNA loosely packed in long ______fibers
  • ______for mitosis
  • replicates ______
  • DNA & proteins
  • produces ______

S Phase: Copying/Replicating DNA

  • ______phase of Interphase
  • dividing cell replicates ______
  • must ______copies correctly to 2 daughter cells
  • human cell duplicates ~____ meters DNA
  • each daughter cell gets ______copy
  • error rate = ~___ per 100 million bases
  • 3 billion base pairs in mammalian ______
  • ~____ errors per cell cycle
  • ______(to somatic (body) cells)

Organizing DNA

  • DNA is organized in ______
  • ______helix DNA molecule
  • wrapped around ______proteins
  • like thread on spools
  • DNA-protein complex =______
  • organized into long thin fiber
  • ______further during mitosis

Copying DNA and Packaging it…

  • After DNA duplication, chromatin condenses
  • ______to make a smaller package

Mitotic Chromosome

  • Duplicated chromosome

2 ______

narrow at ______

contain ______copies of original DNA

Mitosis

Dividing cell’s ______between 2 daughter nuclei

Mitosis is divided into 4 phases

–______

______

–______

–______

–______

Prophase

______hours

Replicated chromosomes ______

–chromatin fibers condense into ______--length reduced ______

Nuclear envelope ______

–allows ______to interact with chromosomes

Nucleolus ______

Mitotic ______forms

–microtubules between two ______or

–______

Spindle apparatus assembles and attaches to ______

Prometaphase

______

–______that binds to ______& attaches chromosome to spindle

–Found at centromere

Kinetochore ______

–attach to kinetochores

–put ______into motion

Nonkinetochore microtubules

–radiate from______toward metaphase plate ______attaching to chromosomes

–non-k microtubules radiating from one pole overlap with those from opposite pole

Metaphase

______minutes

Replicated chromosomes ______in center of cell

Centrosomes positioned at ______poles of cell

______from microtubules on each kinetochore/microtubule connection

–allows proper ______of chromosomes

Anaphase

______minutes

Sister ______separate at ______and begin to move to opposite ends of cell

–Pulled by ______

Separated chromatids are now called ______chromosomes

Separation of chromatids

In anaphase, proteins holding together sister chromatids are ______

Separate to become individual ______

–Kinetochore microtubules use ______proteins that walk chromosome along attached ______

•Microtubule shortens by dismantling at ______(chromosome end)
•______
•______process requiring ______

Telophase

______minutes

Spindle apparatus ______

Nuclear membranes begin to ______around each set of chromosomes

Nucleoli ______

Chromosomes ______

Cytokinesis

  • Animals
  • constriction belt of ______microfilaments around equator of cell
  • ______forms
  • splits cell in ______
  • like tightening a draw string
  • Plants
  • ______forms
  • ______line up at equator
  • derived from ______
  • vesicles fuse to form 2 ______
  • new ______laid down between membranes
  • new cell wall fuses with existing cell wall

Evolution of Mitosis

  • Mitosis in ______likely evolved from ______in bacteria
  • ______chromosome
  • ______membrane-bound organelles

A possible progression of mechanisms intermediate between binary fission & mitosis seen in modern organisms

AP Biology McClure-Ottmers

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