Materials move through cells by diffusion. Oxygen and food move into cells, while waste products move out of cells. How does the size of a cell affect how efficiently materials get to all parts of a cell?
Work with a partner to complete this activity
1. On a sheet of paper, make a drawing of a cell that has the following dimensions: 5 cm x 5 cm x 5 cm. Your partner should draw another cell about one half the size of your cell on a separate sheet of paper.
2. Compare your drawings. How much longer do you think it would taketo get from the cell membrane to the center of the big cell than from the cell membrane to the center of the smaller cell?
3.What is the advantage of cells being small?
It would take twice the amount of time.
If cells are small, materials can be distributed to all parts of the cell quickly.
Image from: http://www.bcps.org/offices/lis/models/life/images/grow.JPG
Image by Riedell
CELL GROWTH & DIVISION10-1 & 10-2
2 Reasons why cells divide
1. _____________________As cell grows bigger demand on DNA“genetic library” becomes too great
Ex: Small town library has 1000 books. As town grows and more people borrow books, there may be a waiting list to read the most popular titles
DNA OVERLOAD
http://www.adc.state.az.us/images/Off-Library.JPG
2 Reasons why cells divide
2. _____________________As cell grows bigger demand for transport across membrane is too great
Material exchange can’t keep up
http://www.animationlibrary.com
Ability to transport of oxygen, food, waste across cell membrane depends on _______________
Need for these depends on ___________
SURFACE AREA
CELL VOLUME
As cell grows these DON’T increase at the same rate
See relationshipbetween volume and SA
Go to Section:
Cell Size
Surface Area (length x width x 6)Volume (length x width x height)
Ratio of Surface Area to Volume
Ratio of Surface Area to Volume in Cells
Section 10-1
BIGGER CELLS NEED MORE FOODand OXYGEN, but CAN’T
TRANSPORTIT FAST ENOUGH or IN BIGENOUGH QUANTITIES!
http://www.animationlibrary.com
Multicellular organisms grow mainly by increasing cell number
Image from: http://www.bcps.org/offices/lis/models/life/images/grow.JPGImage by Riedell
SPREAD OUT INNON-DIVIDING CELLS
SCRUNCHED UPIN DIVIDINGCELLS
CHROMATIN CHROMOSOMES
DNA CAN BE:
DNA in PROKARYOTES
• BACTERIAL DNA is CIRCULAR• HAVE ONE CHROMOSOME• NO NUCLEUS;
ATTACHED TO CELL MEMBRANE
http://www.origin-life.gr.jp/3202/3202121/fig6.jpg
DNA in EUKARYOTES(Plants & Animals)
• DNA is ROD-SHAPED CHROMOSOMES• MANY PAIRS• FOUND IN NUCLEUS
http://cellbio.utmb.edu/cellbio/chrom2.jpg
Chromosome structure
• ___________________ 2 identical arms
• __________________ constricted area
holds chromatids together
•__________________ PAIR 2 of each chromosome(one from mom; one from dad)
CHROMATIDS
CENTROMERE
HOMOLOGOUS
HOMOLOGOUS CHROMOSOMES
http://arnica.csustan.edu/biol3020/cell_division/cell_division.htm
• SAME SIZE• SAME SHAPE• CARRY GENES for the
SAME TRAITS• BUT ______________! (Don’t have to have
the SAME CHOICES)
http://sps.k12.ar.us/massengale/genetics%20tutorial.htm
NOT IDENTICAL
CELL DIVISION in PROKARYOTES
Bacteria reproduce using__________________________________ BINARY FISSION
http://fig.cox.miami.edu/~cmallery/150/mitosis/fission.jpg
______________ =series of events that cells go through as they grow and develop
cells alive cell cycle
CELL CYCLE
CELL CYCLEINTERPHASE – non-dividing phase G1- Grow bigger
Cell is “doing its job” DNA is spread out as
chromatin
S - Synthesis (copy DNA)& chromosomal proteins
G2- Grow bigger, make organelles &
molecules needed for cell division
CELL DIVISIONMITOSIS – Nuclear division Prophase Metaphase
AnaphaseTelophaseCytokinesis – Cytoplasm divides
G0 – cell stops dividing (Ex: nerve cell)
Go to Section:
M phase
G2 phase
S phase
G1 phase
Figure 10–4 The Cell Cycle
Section 10-2
INTERPHASE (G1 - S - G2)
In between divisionsCells are in this phase most of the timeCan see nucleus DNA spread out as chromatin
Can’t see chromosomes DNA gets copied (S)
Cell gets ready to divide
PROPHASE1st dividing phase
Spindle fibers form & attach to chromosomes
Nuclear membrane & nucleolus disappear
DNA scrunches into chromosomes
Centrioles appear in centrosome region & move to poles
Pearson Education Inc publishing as Pearson Prentice Hall
http://www.life.uiuc.edu/plantbio/102/lectures/08mit&veg102.html
________ region organizes spindle
Spindle MICROTUBULES are part of cytoskeletonhttp://www.coleharbourhigh.ednet.ns.ca/library/organelle_worksheet.htm
CENTROSOME
METAPHASE
Chromosomes line up in ___________middle
Images from:Pearson Eduction Ince; Publishing as Pearson Prentice Hall http://www.science.siu.edu/plant-biology/PLB117/JPEGs%20CD/0247.JPG
ANAPHASECentromeres splitCentrioles pull chromatids_______apart
Images from:Pearson Eduction Ince; Publishing as Pearson Prentice Hall http://www.science.siu.edu/plant-biology/PLB117/JPEGs%20CD/0247.JPG
TELOPHASE (reverse prophase steps)
See ______ nuclei
Nuclear membrane & nucleolus returnChromosomes spread out as chromatinCentrioles disappear
Spindle fibers disappear
two
Images from:Pearson Eduction Ince; Publishing as Pearson Prentice Hallhttp://www2.bc.cc.ca.us/cnewton/Biology%2011/Mitosis.html
CYTOKINESISCytoplasm splits into 2 cells
ANIMAL CELLS pinch cytoplasm in two with a ______________________CLEAVAGE FURROW
CYTOKINESISCytoplasm splits into 2 cellsPLANT CELLS can’t pinch because they have a sturdy ____________
Plant cells separate cytoplasm by growing a _______________ down the middle.
CELL PLATE
CELL WALL
http://www.eastcentral.edu/acad/depts/BI/plant_mitosis_nolabels.html
Go to Section:
Centrioles
Chromatin
Interphase
Nuclear envelope
Cytokinesis
Nuclear envelope reforming
Telophase
Anaphase
Individual chromosomes
Metaphase
Centriole
Spindle
CentrioleChromosomes
(paired chromatids)
Prophase
Centromere
Spindle forming
Section 10-2
Figure 10–5 Mitosis and Cytokinesis
Go to Section:
Centrioles
Chromatin
Interphase
Nuclear envelope
Cytokinesis
Nuclear envelope reforming
Telophase
Anaphase
Individual chromosomes
Metaphase
Centriole
Spindle
CentrioleChromosomes
(paired chromatids)
Prophase
Centromere
Spindle forming
Section 10-2
Figure 10–5 Mitosis and Cytokinesis
Go to Section:
Centrioles
Chromatin
Interphase
Nuclear envelope
Cytokinesis
Nuclear envelope reforming
Telophase
Anaphase
Individual chromosomes
Metaphase
Centriole
Spindle
CentrioleChromosomes
(paired chromatids)
Prophase
Centromere
Spindle forming
Section 10-2
Figure 10–5 Mitosis and Cytokinesis
Go to Section:
Centrioles
Chromatin
Interphase
Nuclear envelope
Cytokinesis
Nuclear envelope reforming
Telophase
Anaphase
Individual chromosomes
Metaphase
Centriole
Spindle
CentrioleChromosomes
(paired chromatids)
Prophase
Centromere
Spindle forming
Section 10-2
Figure 10–5 Mitosis and Cytokinesis
Go to Section:
Centrioles
Chromatin
Interphase
Nuclear envelope
Cytokinesis
Nuclear envelope reforming
Telophase
Anaphase
Individual chromosomes
Metaphase
Centriole
Spindle
CentrioleChromosomes
(paired chromatids)
Prophase
Centromere
Spindle forming
Section 10-2
Figure 10–5 Mitosis and Cytokinesis
Go to Section:
Centrioles
Chromatin
Interphase
Nuclear envelope
Cytokinesis
Nuclear envelope reforming
Telophase
Anaphase
Individual chromosomes
Metaphase
Centriole
Spindle
CentrioleChromosomes
(paired chromatids)
Prophase
Centromere
Spindle forming
Section 10-2
Figure 10–5 Mitosis and Cytokinesis
Videos
Animal Cell Mitosis Animal Cell Cytokinesis
Go to Section:
includes
is divided into is divided into
Concept Map
Section 10-2
Cell Cycle
Go to Section:
includes
is divided into is divided into
Concept Map
Section 10-2
Cell Cycle
M phase (Mitosis)
Interphase
G1 phase S phase ProphaseG2 phase Metaphase TelophaseAnaphase
SOUTH DAKOTA CORE SCIENCE STANDARDS
9-12.L.1.1. Students are able to relate cellular functions and processes to specialized structures within cells.
• Transport (ANALYSIS)
cell membranes, homeostasis • Cell life cycles (ANALYSIS)
Examples: somatic cells (mitosis)
LIFE SCIENCE:Indicator 1: Understand the fundamental structures, functions, classifications, and mechanisms found in living things
Core High School Life SciencePerformance Descriptors
High school students performing at the
ADVANCED level:
predict the function of a given structure;
predict the outcome of changes in the cell cycle;
predict how homeostasis is maintained within living systems;
High school students performing at the
PROFICIENT level:
describe the relationship between structure and function
explain how homeostasis is maintained within living
systems;
compare and contrast the cell cycles in somatic and germ cells;
High school students performing at the
BASIC level
recognize that different structures perform different functions
define homeostasis;
describe the life cycle of somatic cells;