materials move through cells by diffusion. oxygen and food move into cells, while waste products...

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

http://trc.ucdavis.edu/biosci10v/bis10v/media/ch03/area_volume.html

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

http://www.cellsalive.com/cell_cycle.htm

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

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;


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;


BASIC level

recognize that different structures perform different functions

define homeostasis;

describe the life cycle of somatic cells;

materials move through cells by diffusion. oxygen and food move into cells, while waste products...

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cells divide1