The Cell Cycle & Cellular Division

The Cell Cycle & Cellular Division

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I. Cell Division:

All _______ are derived from preexisting cells (Cell Theory).

_______________ is the process by which cells produce new cells.

cells

Cell division

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I. Cell Division:

Cells grow in number, NOT in size. Smaller cells more

efficient (cellular transport, cellular communication)

Easier to take in nutrients and get rid of wastes.

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How Often Do Cells Divide? Some cells must be repaired often such as

cells lining the ____________, ____________________, and ____________ with a short lifespan.

Other cells DO NOT divide at all after birth such as ________, nerve cells, _____________, and __________________.

intestines white blood cellsskin cells

muscle brain cellsfemale egg cells

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II. Reasons for Cell Division:Cell ________ ________ and _____________ of

damaged cell partsGrowth and development of an

________

growthRepa

irreplacement

embryo

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IV. Chromosomes & their Structure:The plans for making cells are coded

in _____.DNA, deoxyribose nucleic acid, is a

long, thin molecule that stores ___________________.

DNA is organized into giant molecules called ______________.

DNA

genetic information

chromosomes

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IV. Chromosomes & Their Structure: ________________ are

made of protein and a long, single, tightly-coiled DNA molecule visible only when the cell divides.

When a cell is NOT dividing the chromosome (DNA) is less visible and is called ___________.

Chromosomes

chromatin

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IV. Chromosomes & Their Structure: _____________ hold

duplicated chromoses together before they are separated in mitosis.

When DNA makes copies of itself before cell division, each half of the chromosome is called a __________________ Each sister chromatid contains

____________ genetic information.

Centromeres

sister chromatididentical

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VI. Cell Cycle & Cell Division: Eukaryotes (nucleus and membrane-bound

organelles) must be copied exactly so the two new cells formed division will be _______________ The original parent cell and two new

________________ must have IDENTICAL chromosomes.

Ex: Humans have 46 chromosomes in our _____________ (body cells). After one of these somatic cells goes through mitosis, two daughter cells are produced each having 46 chromosomes (genetically identical).

exactly alikedaughter cells

somatic cells

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VI. Cell Cycle & Cell Division:Both the nucleus (_________) and the

cytoplasm (_____________) must be divided during cell division in eukaryotes.

mitosiscytokinesis

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VI. Cell Cycle & Cell Division:Cells go through phases or a cell

cycle during their life before they divide to form new cells. Cell cycle is about _______ hours for

most animal cells. Cell cycle is controlled by proteins

and _________.

12-24

enzymes

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VI. Cell Cycle & Cell Division:The cell cycle includes 3 main parts -

- - ____________, _________, and _____________. _________ = nuclear division _____________ = division of cytoplasm

interphase

mitosiscytokinesi

smitosiscytokinesis

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A. Interphase:

Interphase is the _________ part of a cell’s life cycle and is called the “resting stage” because the cell isn’t dividing.

Animal Cell Plant Cell

nucleus

longest

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A. Interphase:

Divided into 3 stages:1) ____ (Gap 1) = cell is growing,

carrying out normal cell functions, preparing to replicate DNA.

- Cells mature and increase in size by making more ___________ & ____________

G1

cytoplasm

organelles

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A. Interphase:

2) ___ (synthesis) = DNA is copied or ___________

- DNA is in the form of ___________ (uncoiled DNA) and is NOT _________

Sreplicated

chromatin visible

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A. Interphase:

3) ____ (Gap 2) = cell prepares for nuclear division (mitosis)

- cell makes all the structures needed to ________

G2

divide

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B. 4 Stages of Mitosis:

Division of the nucleus or _________ occurs first.

Mitosis is an _________ method of reproduction Only _____ parent cell Daughter cells have SAME number of

_____________ (genetic info)Mitosis consists of 4 stages - - -

prophase, metaphase, anaphase and telophase.

replicated

asexual

one

chromosomes

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1. Prophase:

_________ phase of MITOSISChromatin (______________)

condenses and coils into the form of chromosomes Chromosomes are visible (shaped like a “X”)

___________________ (half of a “X”) attach to each other by the ____________

Longestuncoiled DNA

Sister chromatids centrome

re

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1. Prophase:

Centrioles in animals cells move to opposite ends of cell.

Spindle forms from each centriole (ONLY in ________ cells) _______ cells ________ have centrioles

(spindle forms from a microtubule) __________________ dissolves

(disappears) ___________ disintegrates

animalPlant DO NOT

Nuclear membraneNucleolus

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1. Prophase:

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2. Metaphase:

__________ phase of MITOSISChromosomes line up in center or

_________ of the cellThe centromere of each chromosome

attaches to spindle fibers.

Shortestequator

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2. Metaphase:

24

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3. Anaphase:

Spindle fibers attached to the centriole pull the ___________________ apart at their centromere.

Separated chromosomes travel along the ________________ to the poles (ends) of the cell.

sister chromatid

spindle fibers

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3. Anaphase:

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4. Telophase:

__________________ forms at each end of the cell around the chromosomes.

___________ reformsSpindle fibers begin to break downChromosomes become less tightly

coiled and appear as ___________ again

Cytokinesis begins

Nuclear membraneNucleolus

chromatin

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4. Telophase:

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Mitosis Animation

http://www.sumanasinc.com/webcontent/animations/content/mitosis.html

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C. Cytokinesis:

_____________ = division of the cytoplasm of the cell and its organelles separate into 2 new daughter cells.

Cytokinesis

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C. Cytokinesis:

In _________, a groove called the _________________ forms pinching the parent cell in two.

animals

cleavage furrow

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C. Cytokinesis:

In ________, a ____________ forms down the middle of the cell where the new __________ will be

plants cell plate cell wall

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C. Cytokinesis:

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VI. Cancer:

Cell division must be controlled, otherwise cell growth will occur without limit (cancer) _____ mutations lead to changes in the

proteins/enzymes that regulate the cell cycle

Cancerous Kidney Cells

DNA

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VI. Cancer:

________ = a cell or group of cells that grown out of control and create a tumor. Crowds out normal cells and results in

the loss of tissue function.Cancerous Kidney Cells

Cancer

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VI. Cancer:

_______ = mass of growing, unregulated cells 2 types of tumors:

1. ________ - tumor that does not spread

2. ___________ - tumor that spreads and destroys healthy tissue

Tumor

BenignMalignant

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Causes of Cancer:

__________ (family history) _________ _____________ (cancer causing

chemicals) _________:

HPV can lead to cancer of reproductive organs ___________:

Sunlight (UV) – skin cancer

GeneticsSmokingCarcinogensVirusesRadiation

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What phase of the cell cycle would this be?

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What phase of the cellcycle would this be?

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What phase of the cellcycle would this be?

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What phase of the cellcycle would this be?

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Can you identify 5 stages?

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Mitosis occurring in ANIMAL CELLS

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Mitosis occurring in PLANT CELLS

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