Cell Growth And Division - PowerPoint PPT Presentation

Loading...

PPT – Cell Growth And Division PowerPoint presentation | free to download - id: 563ba8-MDZhO



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Cell Growth And Division

Description:

Chapter 10 Cell Growth And Division cyclins _____=protein that regulates normal cell cycle (in eukaryotes)-tells cells it s time to divide There are ... – PowerPoint PPT presentation

Number of Views:93
Avg rating:3.0/5.0
Slides: 36
Provided by: lrado
Category:
Tags: cell | cycle | division | growth

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Cell Growth And Division


1
Chapter 10
  • Cell Growth And Division

2
I. Cell Growth
DNA
  • A. Limits to Cell Growth
  • 2 reasons cells divide rather than continuing to
    grow indefinitely
  • 1) larger a cell grows,the more demands on its
    _______
  • will not be making enough copies of DNA as size
    increases---This would cause an information
    crisis.
  • 2) difficult to move waste and nutrients
    across cell
  • rate _at_ which waste products leave cell depends on
    _______________________ of celltotal area of
    cell membrane

Surface area
3
  • rate _at_ which food and Oxygen are used up and
    waste produced depends on _____________________
  • RATIO OF SURFACE AREA TO VOLUME-assuming a cube
    shape,surface areal x w x 6..volume lx w x h.
    ratio
    SA /volume

Cell volume
4
Ratio of Surface Area to Volume in Cells
Section 10-1
Cell Size
Surface Area (length x width x 6)
Volume (length x width x height)
Ratio of Surface Area to Volume
5
  • Volume increases faster than surface area/CAUSING
    RATIO TO __________________..causing serious
    problems for cell --Because a decrease in the
    relative amount of cell membrane available
    compared to increase in cell volume--

decrease
6

B. Division of Cell-before a
growing cell becomes too large
  • Cell division solves the problem of increasing
    size by reducing cell volume
  • -A cell divides into 2 daughter cells
    _______________________________
  • This happens before a cell can get too large
  • DNA ___________________before cell
    division,solving info crisis.

Cell division
replicates
7
C. Cell division and reproduction
  • Asexual-takes one parent and produces genetically
    identical offspring-simple,efficient and
    effective
  • What problems could it present?
  • Some multicellular organisms reproduce by
    budding---example-hydra

8
  • Sexual-takes 2 parents-fusion of reproductive
    cells-new genetic info-some from each
    parent-greater diversity-advantage
  • Comparing asexual and sexual-
  • Asexua l,since it is quick is a survival strategy
  • Ok as long as conditions are favorable
  • Sexual advantage is diversity
  • Some do both-example-yeast

9
(No Transcript)
10
II. Cell Division Process
  • simpler in prokaryotes
  • A. chromosomes carries genetic info in
    eukaryotes
  • made up of ____________ and proteins
  • cells of every organism have a specific of
    Chromosomes
  • humans have___ Chromosomes
  • fruit flies have 8
  • usually not visible except in cell division,when
    they condense
  • ___________________before cell division

46
Replicates or copies
DNA
11
  • each Chromosome consists of 2 identical
    __________________,which separate from each other
    in cell division
  • chromatids attached _at___________________,usually
    near middle

chromatids
centromere
12
(No Transcript)
13
II. Chromosomes DNA Replication
  • A-DNA Chromosomes
  • In cytoplasm in prokaryotes
  • In _______________________found in cell nucleus
    in the form of a number of chromosomes(46
    humans,8 Drosophilia and 22 Sequoia trees)

eukaryotes
14
(No Transcript)
15
  • 1--DNA length
  • 1.6 mm in E.coli(has 4,639,221 base
    pairs)---obviously it must be tightly folded

16
(No Transcript)
17
(No Transcript)
18
(No Transcript)
19
(No Transcript)
20
(No Transcript)
21
(No Transcript)
22
(No Transcript)
23
B. Cell Cycle
  • ________________________is in- between phase
  • ______________________is the series of events
    that a cell goes through during growth and
    division.Where the cell grows,prepare for
    division,divides into 2 daughter cells

interphase
Cell Cycle
24
  • 4 phases
  • M _______________________________
  • S ________________________________
  • G1 and G2 _______________________________________
    _________________

Mitosis and cytokinesis
Chromsomes replicate DNA synthesis,some
proteins synthesize
G1cell growth/G2 organelles and molecules
produced
25
Figure 104 The Cell Cycle
Section 10-2
G1 phase
M phase
S phase
G2 phase
26
ANAPHASE
27
1) Prophase
  • Longest phase
  • Chromosomes become visible
  • _______________________,2 tiny structures near
    nuclear envelope-separate and take positions on
    opposite ends of nucleus
  • Centrosome region helps organize
    __________________-microtubules that help
    separate chromosomes
  • Chromosomes attach to __________________________
  • _at_ end chromosomes coil tightly and nuclear
    envelope disappears

centrioles
Spindle fibers
spindle
28
  • 2) Metaphase-
  • chromosomes line up _at_ center
  • Centromeres go to 2 poles
  • 3) Anaphase-
  • Centromeres split
  • Chromatids separate and become individual
    _____________________
  • New chromosomes go to opposite poles and then
    stop moving

chromosomes
29
  • 4) Telophase-
  • Chromosomes disperse into tangle of material
  • New nuclear envelopes
  • Spindle breaks apart
  • Nucleolus becomes visible

30
  • D. Cytokinesis-divison of cytoplasm
  • Usually along w/ Telophase
  • Cell plate forms in plants that becomes the
    ______________________________
  • Occurs at cleavage furrow in animals,where it
    pinches inward---too rigid to pinch inward in
    plants

CELL WALL
31
(No Transcript)
32
III-Regulating Cell Cycle.
  • Most cells in lab divide until coming in contact
    w/other cells-similar in body
  • _____________________ disorder in which some of
    the bodys cells lose the ability to regulate
    growth
  • They do not respond to signals that regulate
    growth
  • Divide uncontrollably,making ___________________(m
    asses of cells)/not all are cancerous
  • _____________protein that regulates normal cell
    cycle (in eukaryotes)

tumors
cancer
cyclins
33
  • Cancer caused by defect in genes causing cell
    growth and division-oncogene-caused by
    carcinogens such as smoking,chew
    tobacco,radiation,viruses,chemicals-CARCINOGENS,ma
    ny cancers linked to abnormality in p53
    gene-normally halts cell cycle until all
    chromosomes have been replicated
  • Cancer treated by-surgery for tumor
    removal,radiation-tarets DNA replication that is
    happening at accelerated rate, chemotherapy---both
    also affect normal cells

34
cyclins
  • _________________protein that regulates normal
    cell cycle (in eukaryotes)-tells cells its time
    to divide
  • There are regulatory proteins internally and
    externally to the cell-for example(internally)-pro
    teins that make sure replication has happened
    before mitosis/externally-GROWTH
    FACTORS-Stimulate growth or slow down growth-esp.
    important in embryo or wound healing

35
  • APOSTASIS-process of programming cell death(which
    also can die by accidents)-key role in tissue and
    organ development-AIDS and Parkinsons are
    examples of if apoptosis is not regulated
About PowerShow.com