topic 4 cell growth & division chapter 10: the cell cycle and mitosis biology- waugaman -...

Topic 4Topic 4Cell Growth & Cell Growth &

Division Division

Topic 4Topic 4Cell Growth & Cell Growth &

Division Division Chapter 10: Chapter 10: The Cell The Cell

Cycle and MitosisCycle and MitosisChapter 10: Chapter 10: The Cell The Cell

Cycle and MitosisCycle and Mitosis

BIOLOGY- WAUGAMAN - LATHROPBIOLOGY- WAUGAMAN - LATHROP

Twilight Mitosis Twilight Mitosis Twilight Mitosis Twilight Mitosis

• https://www.youtube.com/watch/?v=sOM_u1PY0s0• https://www.youtube.com/watch/?v=sOM_u1PY0s0

https://www.youtube.com/watch/?v=sOM_u1PY0s0

https://www.youtube.com/watch/?v=sOM_u1PY0s0

10.1 Cell Growth, Division, and reproduction 10.1 Cell Growth, Division, and reproduction Limits to Cell SizeLimits to Cell Size10.1 Cell Growth, Division, and reproduction 10.1 Cell Growth, Division, and reproduction Limits to Cell SizeLimits to Cell Size

• Cells come in all shapes and sizes…the Cells come in all shapes and sizes…the smallest are bacteria cells…the largest is smallest are bacteria cells…the largest is the ostrich egg….the ostrich egg….

……the largest human the largest human cell is the female eggcell is the female egg

• Cells come in all shapes and sizes…the Cells come in all shapes and sizes…the smallest are bacteria cells…the largest is smallest are bacteria cells…the largest is the ostrich egg….the ostrich egg….

……the largest human the largest human cell is the female eggcell is the female egg

10.1 Cell Growth, Division, and reproduction10.1 Cell Growth, Division, and reproduction

Factors Affecting Cell Factors Affecting Cell Size Size


Factors Affecting Cell Factors Affecting Cell Size Size

Three things that limit cell size:Three things that limit cell size:

1.1. Rate of DiffusionRate of Diffusion

2.2. Amount of DNAAmount of DNA

3.3. Surface Area-to-Volume ratio of Surface Area-to-Volume ratio of cellcell

Three things that limit cell size:Three things that limit cell size:

1.1. Rate of DiffusionRate of Diffusion

2.2. Amount of DNAAmount of DNA

3.3. Surface Area-to-Volume ratio of Surface Area-to-Volume ratio of cellcell


1. 1. DiffusionDiffusion Limits Cell Limits Cell SizeSize


1. 1. DiffusionDiffusion Limits Cell Limits Cell SizeSize

• Nutrients, oxygen, water & wastes must Nutrients, oxygen, water & wastes must pass through the membrane efficiently.pass through the membrane efficiently.

• Diffusion is fast and efficient over a short Diffusion is fast and efficient over a short distance.distance.– Slow and inefficient as distance becomes Slow and inefficient as distance becomes

greater.greater.

• Because of the slow rate, organisms Because of the slow rate, organisms cannot be just one giant cell. The cannot be just one giant cell. The organelles would “starve” waiting for organelles would “starve” waiting for necessary nutrients to “diffuse“ to them, necessary nutrients to “diffuse“ to them, and wastes would build up in the cell.and wastes would build up in the cell.

• Nutrients, oxygen, water & wastes must Nutrients, oxygen, water & wastes must pass through the membrane efficiently.pass through the membrane efficiently.

• Diffusion is fast and efficient over a short Diffusion is fast and efficient over a short distance.distance.– Slow and inefficient as distance becomes Slow and inefficient as distance becomes

greater.greater.

• Because of the slow rate, organisms Because of the slow rate, organisms cannot be just one giant cell. The cannot be just one giant cell. The organelles would “starve” waiting for organelles would “starve” waiting for necessary nutrients to “diffuse“ to them, necessary nutrients to “diffuse“ to them, and wastes would build up in the cell.and wastes would build up in the cell.


2. 2. DNADNA Limits Cell SizeLimits Cell Size10.1 Cell Growth, Division, and reproduction10.1 Cell Growth, Division, and reproduction

2. 2. DNADNA Limits Cell SizeLimits Cell Size

• We talked about how We talked about how the nucleus the nucleus contains the code or blueprints for contains the code or blueprints for proteins...proteins...

• Proteins are used throughout the cell to Proteins are used throughout the cell to perform various cell functions.perform various cell functions.

• There’s a limit to how fast the nucleus There’s a limit to how fast the nucleus can instruct the ribosomes to make the can instruct the ribosomes to make the proteins.proteins.

• The cell cannot survive unless there is The cell cannot survive unless there is enough DNA to support the protein needs enough DNA to support the protein needs of the cell.of the cell.

• We talked about how We talked about how the nucleus the nucleus contains the code or blueprints for contains the code or blueprints for proteins...proteins...

• Proteins are used throughout the cell to Proteins are used throughout the cell to perform various cell functions.perform various cell functions.

• There’s a limit to how fast the nucleus There’s a limit to how fast the nucleus can instruct the ribosomes to make the can instruct the ribosomes to make the proteins.proteins.

• The cell cannot survive unless there is The cell cannot survive unless there is enough DNA to support the protein needs enough DNA to support the protein needs of the cell.of the cell.

I Love Lucy Chocolate Factory

https://www.youtube.com/watch?v=8NPzLBSBzPI


3. 3. Surface Area Surface Area to to VolumeVolume Ratio Ratio


3. 3. Surface Area Surface Area to to VolumeVolume Ratio Ratio

• As a cell’s size increases, its As a cell’s size increases, its volume volume increases much faster than its surface increases much faster than its surface area.area.

• Increased volume means the cell needs Increased volume means the cell needs more nutrients and produces more wastemore nutrients and produces more waste

• However, if the surface area does not However, if the surface area does not increase relative to the volume, the increase relative to the volume, the surface area cannot support the volume’s surface area cannot support the volume’s needs… and the cell will die!needs… and the cell will die!

• As a cell’s size increases, its As a cell’s size increases, its volume volume increases much faster than its surface increases much faster than its surface area.area.

• Increased volume means the cell needs Increased volume means the cell needs more nutrients and produces more wastemore nutrients and produces more waste

• However, if the surface area does not However, if the surface area does not increase relative to the volume, the increase relative to the volume, the surface area cannot support the volume’s surface area cannot support the volume’s needs… and the cell will die!needs… and the cell will die!


DNA StructuresDNA Structures of Cell Cycleof Cell Cycle10.1 Cell Growth, Division, and reproduction10.1 Cell Growth, Division, and reproduction

DNA StructuresDNA Structures of Cell Cycleof Cell Cycle

• ChromatinChromatin – – long, uncoiled long, uncoiled strands of DNA…this is the strands of DNA…this is the DNA structure during most of DNA structure during most of the cell’s life.the cell’s life.

• ChromosomesChromosomes – Tightly – Tightly coiled structure of DNA, coiled structure of DNA, forms before cell replication.forms before cell replication. • Carries the genetic material (DNA) that is Carries the genetic material (DNA) that is

copied and passed from generation to copied and passed from generation to generation of cells.generation of cells.

• This genetic material is This genetic material is crucial to the crucial to the identity of the cell.identity of the cell.

• ChromatinChromatin – – long, uncoiled long, uncoiled strands of DNA…this is the strands of DNA…this is the DNA structure during most of DNA structure during most of the cell’s life.the cell’s life.

• ChromosomesChromosomes – Tightly – Tightly coiled structure of DNA, coiled structure of DNA, forms before cell replication.forms before cell replication. • Carries the genetic material (DNA) that is Carries the genetic material (DNA) that is

copied and passed from generation to copied and passed from generation to generation of cells.generation of cells.

• This genetic material is This genetic material is crucial to the crucial to the identity of the cell.identity of the cell.

ChromatinChromatin

ChromosomesChromosomes


DNA StructuresDNA Structures of Cell Cycleof Cell Cycle10.1 Cell Growth, Division, and reproduction10.1 Cell Growth, Division, and reproduction

DNA StructuresDNA Structures of Cell Cycleof Cell Cycle

• Sister ChromatidsSister Chromatids – 2 halves of – 2 halves of the duplicated chromosomes.the duplicated chromosomes.• Sister chromatids and the Sister chromatids and the

DNA they contain are DNA they contain are exact exact copies copies of each other.of each other.

• They are formed when DNA is They are formed when DNA is replicated (copied) during replicated (copied) during interphaseinterphase

• CentromereCentromere – a protein structure – a protein structure that that holds the two sister holds the two sister chromatids together.chromatids together.• Plays a role in chromosome Plays a role in chromosome

movement during mitosis.movement during mitosis.

• Sister ChromatidsSister Chromatids – 2 halves of – 2 halves of the duplicated chromosomes.the duplicated chromosomes.• Sister chromatids and the Sister chromatids and the

DNA they contain are DNA they contain are exact exact copies copies of each other.of each other.

• They are formed when DNA is They are formed when DNA is replicated (copied) during replicated (copied) during interphaseinterphase

• CentromereCentromere – a protein structure – a protein structure that that holds the two sister holds the two sister chromatids together.chromatids together.• Plays a role in chromosome Plays a role in chromosome

movement during mitosis.movement during mitosis.

sistersister

sistersister

CentromereCentromere


Purpose of Sister Purpose of Sister ChromatidsChromatids


Purpose of Sister Purpose of Sister ChromatidsChromatids

• Before Cell Replication the Before Cell Replication the cell cell COPIESCOPIES all the strands all the strands of DNA in the nucleus. of DNA in the nucleus.

• All the strands of DNA now All the strands of DNA now coil up coil up to form to form chromosomeschromosomes

• The copies for each The copies for each chromosome are chromosome are “tied” “tied” together by the centromeretogether by the centromere. . – Why copy DNA?Why copy DNA?

– Why does DNA coil into a Why does DNA coil into a chromosome?chromosome?

– Why tie together copies?Why tie together copies?

• Before Cell Replication the Before Cell Replication the cell cell COPIESCOPIES all the strands all the strands of DNA in the nucleus. of DNA in the nucleus.

• All the strands of DNA now All the strands of DNA now coil up coil up to form to form chromosomeschromosomes

• The copies for each The copies for each chromosome are chromosome are “tied” “tied” together by the centromeretogether by the centromere. . – Why copy DNA?Why copy DNA?

– Why does DNA coil into a Why does DNA coil into a chromosome?chromosome?

– Why tie together copies?Why tie together copies?


Chromosome NumbersChromosome Numbers10.1 Cell Growth, Division, and reproduction10.1 Cell Growth, Division, and reproduction

Chromosome NumbersChromosome Numbers

• Organism with most chromosomes is Organism with most chromosomes is a fern with 630 different a fern with 630 different chromosomes.chromosomes.– 2n =1,260 strands of DNA 2n =1,260 strands of DNA

• Humans have 23 pairs of Humans have 23 pairs of chromosomes.chromosomes.– Haploid (1n) = 23 Haploid (1n) = 23 different chromosomes different chromosomes

– Diploid (2n) = 23 pair = 46 Diploid (2n) = 23 pair = 46 chromosomes chromosomes

– 23 chromosomes from mom and 23 chromosomes from dad23 chromosomes from mom and 23 chromosomes from dad

• Organism with most chromosomes is Organism with most chromosomes is a fern with 630 different a fern with 630 different chromosomes.chromosomes.– 2n =1,260 strands of DNA 2n =1,260 strands of DNA

• Humans have 23 pairs of Humans have 23 pairs of chromosomes.chromosomes.– Haploid (1n) = 23 Haploid (1n) = 23 different chromosomes different chromosomes

– Diploid (2n) = 23 pair = 46 Diploid (2n) = 23 pair = 46 chromosomes chromosomes

– 23 chromosomes from mom and 23 chromosomes from dad23 chromosomes from mom and 23 chromosomes from dad


The Cell CycleThe Cell Cycle10.1 Cell Growth, Division, and reproduction10.1 Cell Growth, Division, and reproduction

The Cell CycleThe Cell Cycle

• The series of events that occurs during the life of a cell is called the Cell Cycle.

• Why Do Cells Divide?Why Do Cells Divide?• Reproduction

• Growth

• Repair

• The series of events that occurs during the life of a cell is called the Cell Cycle.

• Why Do Cells Divide?Why Do Cells Divide?• Reproduction

• Growth

• Repair

10.2 The Process of cell Division 10.2 The Process of cell Division

Stages of Cell CycleStages of Cell Cycle10.2 The Process of cell Division 10.2 The Process of cell Division

Stages of Cell CycleStages of Cell Cycle

• InterphaseInterphase• ProphaseProphase

• MetaphaseMetaphase

• AnaphaseAnaphase

• TelephaseTelephase

• CytokinesisCytokinesis– IPMATIPMAT

• InterphaseInterphase• ProphaseProphase

• MetaphaseMetaphase

• AnaphaseAnaphase

• TelephaseTelephase

• CytokinesisCytokinesis– IPMATIPMAT

Phases Phases

OF OF

MITOSISMITOSIS

10.2 The Process of cell Division10.2 The Process of cell Division

INTERPHASE – INTERPHASE – not very not very

“interesting” “interesting”


INTERPHASE – INTERPHASE – not very not very

“interesting” “interesting”

• Interphase is when a Cell is in a “working” phase, performing normal cell functions (metabolism)

• At the end of Interphase Organelles (including the chromosomes) double in number, to prepare for division.

• Interphase is when a Cell is in a “working” phase, performing normal cell functions (metabolism)

• At the end of Interphase Organelles (including the chromosomes) double in number, to prepare for division.


INTERPHASEINTERPHASE10.2 The Process of cell Division10.2 The Process of cell Division

INTERPHASEINTERPHASE

• Longest part of the cell cycle…Longest part of the cell cycle…broken into Stages:broken into Stages:• GG11 (Growth 1) (Growth 1) - The cell grows in size

• SS (Synthesis) (Synthesis) – DNA copies

• GG22 (Growth 2)(Growth 2) – Cell prepares for division

• Longest part of the cell cycle…Longest part of the cell cycle…broken into Stages:broken into Stages:• GG11 (Growth 1) (Growth 1) - The cell grows in size

• SS (Synthesis) (Synthesis) – DNA copies

• GG22 (Growth 2)(Growth 2) – Cell prepares for division

• Normal Normal metabolic metabolic activitiesactivities

• DNA is DNA is chromatinchromatin

• Nuclear Nuclear Membrane Membrane PresentPresent


Cell in InterphaseCell in Interphase10.2 The Process of cell Division10.2 The Process of cell Division

Cell in InterphaseCell in Interphase


Mitosis – Mitosis – Cell DivisionCell Division10.2 The Process of cell Division10.2 The Process of cell Division

Mitosis – Mitosis – Cell DivisionCell Division• Process by which Process by which a Somatic (BODY) cell divides a Somatic (BODY) cell divides

into 2 identical daughter cells.into 2 identical daughter cells.• Each new cell has a complete set of chromosomes. Each new cell has a complete set of chromosomes.

Why is this important?Why is this important?• In nuclear division (MITOSIS), the number of

chromosomes remains the same. Why is this Why is this important?important?

• Phases of Mitosis:Phases of Mitosis:1.1. ProphaseProphase2.2. MetaphaseMetaphase3.3. AnaphaseAnaphase4.4. TelophaseTelophase

• Process by which Process by which a Somatic (BODY) cell divides a Somatic (BODY) cell divides into 2 identical daughter cells.into 2 identical daughter cells.• Each new cell has a complete set of chromosomes. Each new cell has a complete set of chromosomes.

Why is this important?Why is this important?• In nuclear division (MITOSIS), the number of

chromosomes remains the same. Why is this Why is this important?important?

• Phases of Mitosis:Phases of Mitosis:1.1. ProphaseProphase2.2. MetaphaseMetaphase3.3. AnaphaseAnaphase4.4. TelophaseTelophase


Summary of MitosisSummary of Mitosis10.2 The Process of cell Division10.2 The Process of cell Division

Summary of MitosisSummary of Mitosis

• One parent cell divides to create 2 One parent cell divides to create 2 daughter cells that are identical in DNA daughter cells that are identical in DNA and Function as the original cell.and Function as the original cell.

• One parent cell divides to create 2 One parent cell divides to create 2 daughter cells that are identical in DNA daughter cells that are identical in DNA and Function as the original cell.and Function as the original cell.

This Organism’s Cells have 2 different Chromosomes

Cyt

okin

esis


Mitosis - Mitosis - #1 #1 PROPHASEPROPHASE


Mitosis - Mitosis - #1 #1 PROPHASEPROPHASE

Events & Structures in Prophase:Events & Structures in Prophase:

1.1. Spindle fibers form “Protein Ropes”Spindle fibers form “Protein Ropes”2.2. Centrioles move to opposite poles Centrioles move to opposite poles

“Anchors” “Anchors” 3.3. Chromosomes become visible “Coil Chromosomes become visible “Coil

Up”Up”4.4. Nuclear membrane begins to Nuclear membrane begins to

disappeardisappear5.5. Nucleolus has disappearedNucleolus has disappeared

• In plants, the spindles form without the In plants, the spindles form without the centrioles.centrioles.

Events & Structures in Prophase:Events & Structures in Prophase:

1.1. Spindle fibers form “Protein Ropes”Spindle fibers form “Protein Ropes”2.2. Centrioles move to opposite poles Centrioles move to opposite poles

“Anchors” “Anchors” 3.3. Chromosomes become visible “Coil Chromosomes become visible “Coil

Up”Up”4.4. Nuclear membrane begins to Nuclear membrane begins to

disappeardisappear5.5. Nucleolus has disappearedNucleolus has disappeared

• In plants, the spindles form without the In plants, the spindles form without the centrioles.centrioles.


PROPHASEPROPHASE10.2 The Process of cell Division10.2 The Process of cell Division

PROPHASEPROPHASE

EARLY PROPHASEEARLY PROPHASE LATE PROPHASELATE PROPHASE


Mitosis - Mitosis - #2 #2 METAPHASEMETAPHASE


Mitosis - Mitosis - #2 #2 METAPHASEMETAPHASE

• Chromosomes line up along the equator.Chromosomes line up along the equator.• Spindles attach to centromeres.Spindles attach to centromeres.

• Chromosomes line up along the equator.Chromosomes line up along the equator.• Spindles attach to centromeres.Spindles attach to centromeres.


Mitosis - Mitosis - #3 #3 AANAPHASENAPHASE10.2 The Process of cell Division10.2 The Process of cell Division

Mitosis - Mitosis - #3 #3 AANAPHASENAPHASE• Centromeres divide or pulled Centromeres divide or pulled AApartpart• Chromatids separate and move to opposite Chromatids separate and move to opposite

polespoles

• Centromeres divide or pulled Centromeres divide or pulled AApartpart• Chromatids separate and move to opposite Chromatids separate and move to opposite

polespoles

ChromatidsChromatids


Mitosis - Mitosis - #4 #4 TELOPHASETELOPHASE


Mitosis - Mitosis - #4 #4 TELOPHASETELOPHASE

• Nuclear membrane begins to form around each group Nuclear membrane begins to form around each group of chromosomes.of chromosomes.

• Chromosomes unwind into chromatinChromosomes unwind into chromatin• Cytokinesis beginsCytokinesis begins

• Nuclear membrane begins to form around each group Nuclear membrane begins to form around each group of chromosomes.of chromosomes.

• Chromosomes unwind into chromatinChromosomes unwind into chromatin• Cytokinesis beginsCytokinesis begins


CYTOKINESISCYTOKINESIS10.2 The Process of cell Division10.2 The Process of cell Division

CYTOKINESISCYTOKINESIS

• The process by which The process by which the the cytoplasm divides and one cytoplasm divides and one cell becomes two individual cell becomes two individual cells. cells.

• The process is different in The process is different in plants and animalsplants and animals• Animals - Animals - cell pinches inwardcell pinches inward• Plants - Plants - a new cell wall forms a new cell wall forms

between the two new cells…this between the two new cells…this wall is called a cell plate.wall is called a cell plate.

• The process by which The process by which the the cytoplasm divides and one cytoplasm divides and one cell becomes two individual cell becomes two individual cells. cells.

• The process is different in The process is different in plants and animalsplants and animals• Animals - Animals - cell pinches inwardcell pinches inward• Plants - Plants - a new cell wall forms a new cell wall forms

between the two new cells…this between the two new cells…this wall is called a cell plate.wall is called a cell plate.


CYTOKINESISCYTOKINESIS10.2 The Process of cell Division10.2 The Process of cell Division

CYTOKINESISCYTOKINESIS

2 Identical Daughter 2 Identical Daughter Cells Result from Cells Result from

CytokinesisCytokinesis

Interphase Begins Interphase Begins again in each new cellagain in each new cell


Results of MitosisResults of Mitosis10.2 The Process of cell Division10.2 The Process of cell Division

Results of MitosisResults of Mitosis

• A process of Mitosis A process of Mitosis guarantees guarantees genetic continuity.genetic continuity.• One cell produces two new One cell produces two new

identical cellsidentical cells

• These two cells will do the same (in These two cells will do the same (in structure and function) as the structure and function) as the parent cell.parent cell.

• A process of Mitosis A process of Mitosis guarantees guarantees genetic continuity.genetic continuity.• One cell produces two new One cell produces two new

identical cellsidentical cells

• These two cells will do the same (in These two cells will do the same (in structure and function) as the structure and function) as the parent cell.parent cell.


Visualizing the Cell CycleVisualizing the Cell Cycle10.2 The Process of cell Division10.2 The Process of cell Division

Visualizing the Cell CycleVisualizing the Cell Cycle

10.3 regulating the Cell Cycle 10.3 regulating the Cell Cycle Controls on Cell DivisionControls on Cell Division10.3 regulating the Cell Cycle 10.3 regulating the Cell Cycle Controls on Cell DivisionControls on Cell Division

– How is the cell cycle How is the cell cycle regulated?regulated?

• The cell cycle is controlled The cell cycle is controlled by regulatory proteins both inside by regulatory proteins both inside and outside the cell.and outside the cell.

– How is the cell cycle How is the cell cycle regulated?regulated?

• The cell cycle is controlled The cell cycle is controlled by regulatory proteins both inside by regulatory proteins both inside and outside the cell.and outside the cell.

10.3 regulating the Cell Cycle10.3 regulating the Cell Cycle10.3 regulating the Cell Cycle10.3 regulating the Cell Cycle

The controls on cell growth and division can be turned The controls on cell growth and division can be turned on and off.on and off.–For example, when an injury such as a broken bone For example, when an injury such as a broken bone occurs, cells are stimulated to divide rapidly and start occurs, cells are stimulated to divide rapidly and start the healing process. The rate of cell division slows the healing process. The rate of cell division slows when the healing process nears completion.when the healing process nears completion.

The controls on cell growth and division can be turned The controls on cell growth and division can be turned on and off.on and off.–For example, when an injury such as a broken bone For example, when an injury such as a broken bone occurs, cells are stimulated to divide rapidly and start occurs, cells are stimulated to divide rapidly and start the healing process. The rate of cell division slows the healing process. The rate of cell division slows when the healing process nears completion.when the healing process nears completion.

10.3 regulating the Cell Cycle10.3 regulating the Cell CycleThe Discovery of CyclinsThe Discovery of Cyclins10.3 regulating the Cell Cycle10.3 regulating the Cell CycleThe Discovery of CyclinsThe Discovery of Cyclins

– Cyclins are a family of proteins that regulate Cyclins are a family of proteins that regulate the timing of the cell cycle in eukaryotic cells.the timing of the cell cycle in eukaryotic cells.

– This graph shows how cyclin levels change This graph shows how cyclin levels change throughout the cell cycle in fertilized clam eggs.throughout the cell cycle in fertilized clam eggs.

– Cyclins are a family of proteins that regulate Cyclins are a family of proteins that regulate the timing of the cell cycle in eukaryotic cells.the timing of the cell cycle in eukaryotic cells.

– This graph shows how cyclin levels change This graph shows how cyclin levels change throughout the cell cycle in fertilized clam eggs.throughout the cell cycle in fertilized clam eggs.

10.3 regulating the Cell Cycle10.3 regulating the Cell CycleRegulatory ProteinsRegulatory Proteins10.3 regulating the Cell Cycle10.3 regulating the Cell CycleRegulatory ProteinsRegulatory Proteins

– Internal regulators are Internal regulators are proteins that respond to events proteins that respond to events inside a cell. They allow the cell inside a cell. They allow the cell cycle to proceed only once certain cycle to proceed only once certain processes have happened inside the processes have happened inside the cell.cell.

– External regulators are External regulators are proteins that respond to events proteins that respond to events outside the cell. They direct cells to outside the cell. They direct cells to speed up or slow down the cell speed up or slow down the cell cycle.cycle.

– Growth factors are external Growth factors are external regulators that stimulate the growth regulators that stimulate the growth and division of cells. They are and division of cells. They are important during important during embryonic development and wound and wound healing.healing.

– Internal regulators are Internal regulators are proteins that respond to events proteins that respond to events inside a cell. They allow the cell inside a cell. They allow the cell cycle to proceed only once certain cycle to proceed only once certain processes have happened inside the processes have happened inside the cell.cell.

– External regulators are External regulators are proteins that respond to events proteins that respond to events outside the cell. They direct cells to outside the cell. They direct cells to speed up or slow down the cell speed up or slow down the cell cycle.cycle.

– Growth factors are external Growth factors are external regulators that stimulate the growth regulators that stimulate the growth and division of cells. They are and division of cells. They are important during important during embryonic development and wound and wound healing.healing.

https://www.youtube.com/watch?v=6ofaqvVPo9Q

https://www.youtube.com/watch?v=6ofaqvVPo9Q

10.3 regulating the Cell Cycle10.3 regulating the Cell CycleApoptosisApoptosis10.3 regulating the Cell Cycle10.3 regulating the Cell CycleApoptosisApoptosis

– ApoptosisApoptosis is a process of is a process of programmed cell death.programmed cell death.

– Apoptosis plays a role in Apoptosis plays a role in development by shaping the development by shaping the structure of tissues and organs in structure of tissues and organs in plants and animals. plants and animals.

For example, the foot of a mouse For example, the foot of a mouse

is shaped the way it is partlyis shaped the way it is partly

because the toes undergo apoptosisbecause the toes undergo apoptosis

during tissue development.during tissue development.

– ApoptosisApoptosis is a process of is a process of programmed cell death.programmed cell death.

– Apoptosis plays a role in Apoptosis plays a role in development by shaping the development by shaping the structure of tissues and organs in structure of tissues and organs in plants and animals. plants and animals.

For example, the foot of a mouse For example, the foot of a mouse

is shaped the way it is partlyis shaped the way it is partly

because the toes undergo apoptosisbecause the toes undergo apoptosis

during tissue development.during tissue development.

10.3 regulating the Cell Cycle10.3 regulating the Cell CycleCancer: Uncontrolled Cell GrowthCancer: Uncontrolled Cell Growth10.3 regulating the Cell Cycle10.3 regulating the Cell CycleCancer: Uncontrolled Cell GrowthCancer: Uncontrolled Cell Growth

– How do cancer cells differ How do cancer cells differ from other cells?from other cells?

–What is cancer video clip

– How do cancer cells differ How do cancer cells differ from other cells?from other cells?

–What is cancer video clip

https://www.youtube.com/watch?v=SGaQ0WwZ_0I

https://www.youtube.com/watch?v=SGaQ0WwZ_0I

Cancer: Uncontrolled Cell Cancer: Uncontrolled Cell GrowthGrowthCancer: Uncontrolled Cell Cancer: Uncontrolled Cell GrowthGrowth

– How do cancer cells differ from other cells?How do cancer cells differ from other cells?

– Cancer cells do not respond to the signals Cancer cells do not respond to the signals that regulate the growth of most cells. As a result, that regulate the growth of most cells. As a result, the cells divide uncontrollably.the cells divide uncontrollably.

– How do cancer cells differ from other cells?How do cancer cells differ from other cells?

– Cancer cells do not respond to the signals Cancer cells do not respond to the signals that regulate the growth of most cells. As a result, that regulate the growth of most cells. As a result, the cells divide uncontrollably.the cells divide uncontrollably.

10.3 regulating the Cell Cycle10.3 regulating the Cell Cycle10.3 regulating the Cell Cycle10.3 regulating the Cell Cycle

– Cancer is a Cancer is a disorder in which disorder in which body cells lose the body cells lose the ability to control cell ability to control cell growth.growth.

– Cancer cells Cancer cells divide uncontrollably divide uncontrollably to form a mass of cells to form a mass of cells called a tumor.called a tumor.

– Cancer is a Cancer is a disorder in which disorder in which body cells lose the body cells lose the ability to control cell ability to control cell growth.growth.

– Cancer cells Cancer cells divide uncontrollably divide uncontrollably to form a mass of cells to form a mass of cells called a tumor.called a tumor.

10.3 regulating the Cell Cycle10.3 regulating the Cell Cycle10.3 regulating the Cell Cycle10.3 regulating the Cell Cycle– A benign tumor is A benign tumor is

noncancerous. It does not noncancerous. It does not spread to surrounding healthy spread to surrounding healthy tissue.tissue.

A malignant tumor is cancerous. A malignant tumor is cancerous. It invades and destroys It invades and destroys surrounding healthy tissue and surrounding healthy tissue and can spread to other parts of can spread to other parts of the body. The spread of the body. The spread of cancer cells is called cancer cells is called metastasis. Cancer cells metastasis. Cancer cells absorb nutrients needed by absorb nutrients needed by other cells, block nerve other cells, block nerve connections, and prevent connections, and prevent organs from functioning.organs from functioning.

– A benign tumor is A benign tumor is noncancerous. It does not noncancerous. It does not spread to surrounding healthy spread to surrounding healthy tissue.tissue.

A malignant tumor is cancerous. A malignant tumor is cancerous. It invades and destroys It invades and destroys surrounding healthy tissue and surrounding healthy tissue and can spread to other parts of can spread to other parts of the body. The spread of the body. The spread of cancer cells is called cancer cells is called metastasis. Cancer cells metastasis. Cancer cells absorb nutrients needed by absorb nutrients needed by other cells, block nerve other cells, block nerve connections, and prevent connections, and prevent organs from functioning.organs from functioning.

10.3 regulating the Cell Cycle10.3 regulating the Cell CycleWhat Causes Cancer?What Causes Cancer?10.3 regulating the Cell Cycle10.3 regulating the Cell CycleWhat Causes Cancer?What Causes Cancer?

– Cancers are caused by defects in genes that regulate Cancers are caused by defects in genes that regulate

cell growth and division.cell growth and division.– Some sources of gene defects are smoking tobacco, Some sources of gene defects are smoking tobacco,

radiation exposure, defective genes, and viral infection.radiation exposure, defective genes, and viral infection.– A damaged or defective p53 gene is common in cancer A damaged or defective p53 gene is common in cancer

cells. It causes cells to lose the information needed to respond cells. It causes cells to lose the information needed to respond to growth signals.to growth signals.

– Cancers are caused by defects in genes that regulate Cancers are caused by defects in genes that regulate

cell growth and division.cell growth and division.– Some sources of gene defects are smoking tobacco, Some sources of gene defects are smoking tobacco,

radiation exposure, defective genes, and viral infection.radiation exposure, defective genes, and viral infection.– A damaged or defective p53 gene is common in cancer A damaged or defective p53 gene is common in cancer

cells. It causes cells to lose the information needed to respond cells. It causes cells to lose the information needed to respond to growth signals.to growth signals.

10.3 regulating the Cell Cycle10.3 regulating the Cell CycleTreatments for CancerTreatments for Cancer10.3 regulating the Cell Cycle10.3 regulating the Cell CycleTreatments for CancerTreatments for Cancer

– Some localized tumors Some localized tumors can be removed by surgery.can be removed by surgery.

– Many tumors can be Many tumors can be treated with targeted treated with targeted radiation.radiation.

– Chemotherapy is the Chemotherapy is the use of compounds that kill use of compounds that kill or slow the growth of or slow the growth of cancer cells.cancer cells.

– Some localized tumors Some localized tumors can be removed by surgery.can be removed by surgery.

– Many tumors can be Many tumors can be treated with targeted treated with targeted radiation.radiation.

– Chemotherapy is the Chemotherapy is the use of compounds that kill use of compounds that kill or slow the growth of or slow the growth of cancer cells.cancer cells.

10.3 regulating the Cell Cycle10.3 regulating the Cell CycleTHINK ABOUT ITTHINK ABOUT IT10.3 regulating the Cell Cycle10.3 regulating the Cell CycleTHINK ABOUT ITTHINK ABOUT IT

The human body The human body contains hundreds of contains hundreds of different cell types, and different cell types, and every one of them every one of them develops from the single develops from the single cell that starts the cell that starts the process. How do the process. How do the cells get to be so cells get to be so different from each different from each other?other?

The human body The human body contains hundreds of contains hundreds of different cell types, and different cell types, and every one of them every one of them develops from the single develops from the single cell that starts the cell that starts the process. How do the process. How do the cells get to be so cells get to be so different from each different from each other?other?

10.4 Cell Differentiation 10.4 Cell Differentiation From One Cell to ManyFrom One Cell to Many10.4 Cell Differentiation 10.4 Cell Differentiation From One Cell to ManyFrom One Cell to Many

– How do cells become How do cells become specialized for different functions?specialized for different functions?

– During the development of an During the development of an organism, cells differentiate into organism, cells differentiate into many types of cells.many types of cells.

– How do cells become How do cells become specialized for different functions?specialized for different functions?

– During the development of an During the development of an organism, cells differentiate into organism, cells differentiate into many types of cells.many types of cells.

10.4 Cell Differentiation10.4 Cell Differentiation10.4 Cell Differentiation10.4 Cell Differentiation

– All organisms start life as just All organisms start life as just one cell.one cell.

– Most multicellular organisms Most multicellular organisms pass through an early stage of pass through an early stage of development called an embryo, development called an embryo, which gradually develops into an which gradually develops into an adult organism.adult organism.

– All organisms start life as just All organisms start life as just one cell.one cell.

– Most multicellular organisms Most multicellular organisms pass through an early stage of pass through an early stage of development called an embryo, development called an embryo, which gradually develops into an which gradually develops into an adult organism.adult organism.


– During development, an During development, an organism’s cells become more organism’s cells become more differentiated and specialized for differentiated and specialized for particular functions. particular functions.

– For example, a plant has For example, a plant has specialized cells in its roots, stems, specialized cells in its roots, stems, and leaves. and leaves.

– During development, an During development, an organism’s cells become more organism’s cells become more differentiated and specialized for differentiated and specialized for particular functions. particular functions.

– For example, a plant has For example, a plant has specialized cells in its roots, stems, specialized cells in its roots, stems, and leaves. and leaves.

10.4 Cell Differentiation10.4 Cell DifferentiationDefining DifferentiationDefining Differentiation10.4 Cell Differentiation10.4 Cell DifferentiationDefining DifferentiationDefining Differentiation

– The process by which The process by which cells become specialized is cells become specialized is known as differentiation.known as differentiation.

– During development, During development, cells differentiate into many cells differentiate into many different types and become different types and become specialized to perform certain specialized to perform certain tasks.tasks.

– Differentiated cells carry Differentiated cells carry out the jobs that multicellular out the jobs that multicellular organisms need to stay alive.organisms need to stay alive.

– The process by which The process by which cells become specialized is cells become specialized is known as differentiation.known as differentiation.

– During development, During development, cells differentiate into many cells differentiate into many different types and become different types and become specialized to perform certain specialized to perform certain tasks.tasks.

– Differentiated cells carry Differentiated cells carry out the jobs that multicellular out the jobs that multicellular organisms need to stay alive.organisms need to stay alive.

10.4 Cell Differentiation10.4 Cell DifferentiationMapping DifferentiationMapping Differentiation10.4 Cell Differentiation10.4 Cell DifferentiationMapping DifferentiationMapping Differentiation

– In some organisms, a cell’s role is determined In some organisms, a cell’s role is determined at a specific point in development.at a specific point in development.

– In the worm In the worm C. elegans, C. elegans, daughter cells from daughter cells from each cell division follow a specific path toward a role each cell division follow a specific path toward a role as a particular kind of cell.as a particular kind of cell.

– In some organisms, a cell’s role is determined In some organisms, a cell’s role is determined at a specific point in development.at a specific point in development.

– In the worm In the worm C. elegans, C. elegans, daughter cells from daughter cells from each cell division follow a specific path toward a role each cell division follow a specific path toward a role as a particular kind of cell.as a particular kind of cell.

10.4 Cell Differentiation10.4 Cell DifferentiationDifferentiation in MammalsDifferentiation in Mammals10.4 Cell Differentiation10.4 Cell DifferentiationDifferentiation in MammalsDifferentiation in Mammals

– Cell differentiation in mammals Cell differentiation in mammals is controlled by a number of is controlled by a number of interacting factors in the embryo.interacting factors in the embryo.

– Adult cells generally reach a Adult cells generally reach a point at which their differentiation point at which their differentiation is complete and they can no longer is complete and they can no longer become other types of cells.become other types of cells.

– Cell differentiation in mammals Cell differentiation in mammals is controlled by a number of is controlled by a number of interacting factors in the embryo.interacting factors in the embryo.

– Adult cells generally reach a Adult cells generally reach a point at which their differentiation point at which their differentiation is complete and they can no longer is complete and they can no longer become other types of cells.become other types of cells.

10.4 Cell Differentiation10.4 Cell DifferentiationStem Cells and DevelopmentStem Cells and Development10.4 Cell Differentiation10.4 Cell DifferentiationStem Cells and DevelopmentStem Cells and Development

– What are stem cells?What are stem cells?

– The unspecialized cells from The unspecialized cells from which differentiated cells develop which differentiated cells develop are known as stem cells.are known as stem cells.

– What are stem cells?What are stem cells?

– The unspecialized cells from The unspecialized cells from which differentiated cells develop which differentiated cells develop are known as stem cells.are known as stem cells.


– One of the most important questions in One of the most important questions in biology is how all of the specialized, differentiated biology is how all of the specialized, differentiated cell types in the body are formed from just a single cell types in the body are formed from just a single cellcell

– Biologists say that such a cell is totipotent, Biologists say that such a cell is totipotent, literally able to do everything, to form all the tissues literally able to do everything, to form all the tissues of the body. of the body.

– Only the fertilized egg (ZYGOTE) and the cells Only the fertilized egg (ZYGOTE) and the cells produced by the first few cell divisions of produced by the first few cell divisions of

embryonic development are truly totipotentembryonic development are truly totipotent..

– One of the most important questions in One of the most important questions in biology is how all of the specialized, differentiated biology is how all of the specialized, differentiated cell types in the body are formed from just a single cell types in the body are formed from just a single cellcell

– Biologists say that such a cell is totipotent, Biologists say that such a cell is totipotent, literally able to do everything, to form all the tissues literally able to do everything, to form all the tissues of the body. of the body.

– Only the fertilized egg (ZYGOTE) and the cells Only the fertilized egg (ZYGOTE) and the cells produced by the first few cell divisions of produced by the first few cell divisions of

embryonic development are truly totipotentembryonic development are truly totipotent..

10.4 Cell Differentiation10.4 Cell DifferentiationHuman DevelopmentHuman Development10.4 Cell Differentiation10.4 Cell DifferentiationHuman DevelopmentHuman Development

– After about four days of development, a After about four days of development, a human embryo forms into a human embryo forms into a blastocyst, a , a hollow ball of cells with a cluster of cells hollow ball of cells with a cluster of cells inside known as the inner cell mass. inside known as the inner cell mass.

– The cells of the inner cell mass are said The cells of the inner cell mass are said to be pluripotent, which means that they are to be pluripotent, which means that they are capable of developing into many, but not all, capable of developing into many, but not all, of the body's cell types. of the body's cell types.

– After about four days of development, a After about four days of development, a human embryo forms into a human embryo forms into a blastocyst, a , a hollow ball of cells with a cluster of cells hollow ball of cells with a cluster of cells inside known as the inner cell mass. inside known as the inner cell mass.

– The cells of the inner cell mass are said The cells of the inner cell mass are said to be pluripotent, which means that they are to be pluripotent, which means that they are capable of developing into many, but not all, capable of developing into many, but not all, of the body's cell types. of the body's cell types.

https://www.youtube.com/watch?v=wuuq6FVyJh8

https://www.youtube.com/watch?v=wuuq6FVyJh8

10.4 Cell Differentiation10.4 Cell DifferentiationStem CellsStem Cells10.4 Cell Differentiation10.4 Cell DifferentiationStem CellsStem Cells

– Stem cells are unspecialized Stem cells are unspecialized cells from which differentiated cells cells from which differentiated cells develop.develop.

– There are two types of stem There are two types of stem cells: embryonic and adult stem cells: embryonic and adult stem cells.cells.

– Stem cells are unspecialized Stem cells are unspecialized cells from which differentiated cells cells from which differentiated cells develop.develop.

– There are two types of stem There are two types of stem cells: embryonic and adult stem cells: embryonic and adult stem cells.cells.

10.4 Cell Differentiation10.4 Cell DifferentiationEmbryonic Stem CellsEmbryonic Stem Cells10.4 Cell Differentiation10.4 Cell DifferentiationEmbryonic Stem CellsEmbryonic Stem Cells

– Embryonic stem cells are Embryonic stem cells are found in the inner cells mass of the found in the inner cells mass of the early embryo.early embryo.

– Embryonic stem cells are Embryonic stem cells are pluripotent. pluripotent.

– Researchers have grown stem Researchers have grown stem cells isolated from human embryos cells isolated from human embryos in culture. Their experiments in culture. Their experiments confirmed that embryonic stem confirmed that embryonic stem cells have the capacity to produce cells have the capacity to produce most cell types in the human body.most cell types in the human body.

– Embryonic stem cells are Embryonic stem cells are found in the inner cells mass of the found in the inner cells mass of the early embryo.early embryo.

– Embryonic stem cells are Embryonic stem cells are pluripotent. pluripotent.

– Researchers have grown stem Researchers have grown stem cells isolated from human embryos cells isolated from human embryos in culture. Their experiments in culture. Their experiments confirmed that embryonic stem confirmed that embryonic stem cells have the capacity to produce cells have the capacity to produce most cell types in the human body.most cell types in the human body.

10.4 Cell Differentiation10.4 Cell DifferentiationAdult Stem CellsAdult Stem Cells10.4 Cell Differentiation10.4 Cell DifferentiationAdult Stem CellsAdult Stem Cells

– Adult organisms contain some Adult organisms contain some types of stem cells.types of stem cells.

– Adult stem cells are Adult stem cells are multipotent. They can produce multipotent. They can produce many types of differentiated cells.many types of differentiated cells.

– Adult stem cells of a given Adult stem cells of a given organ or tissue typically produce organ or tissue typically produce only the types of cells that are only the types of cells that are unique to that tissue.unique to that tissue.

– Adult organisms contain some Adult organisms contain some types of stem cells.types of stem cells.

– Adult stem cells are Adult stem cells are multipotent. They can produce multipotent. They can produce many types of differentiated cells.many types of differentiated cells.

– Adult stem cells of a given Adult stem cells of a given organ or tissue typically produce organ or tissue typically produce only the types of cells that are only the types of cells that are unique to that tissue.unique to that tissue.

10.4 Cell Differentiation10.4 Cell DifferentiationFrontiers in Stem Cell ResearchFrontiers in Stem Cell Research10.4 Cell Differentiation10.4 Cell DifferentiationFrontiers in Stem Cell ResearchFrontiers in Stem Cell Research

What are some possible benefits and issues What are some possible benefits and issues associated with stem cell research?associated with stem cell research?

Stem cells offer the potential benefit of using Stem cells offer the potential benefit of using undifferentiated cells to repair or replace badly undifferentiated cells to repair or replace badly damaged cells and tissues.damaged cells and tissues.

Human embryonic stem cell research is controversial Human embryonic stem cell research is controversial because the arguments for it and against it both because the arguments for it and against it both involve ethical issues of life and death.involve ethical issues of life and death.

What are some possible benefits and issues What are some possible benefits and issues associated with stem cell research?associated with stem cell research?

Stem cells offer the potential benefit of using Stem cells offer the potential benefit of using undifferentiated cells to repair or replace badly undifferentiated cells to repair or replace badly damaged cells and tissues.damaged cells and tissues.

Human embryonic stem cell research is controversial Human embryonic stem cell research is controversial because the arguments for it and against it both because the arguments for it and against it both involve ethical issues of life and death.involve ethical issues of life and death.

10.4 Cell Differentiation10.4 Cell DifferentiationPotential BenefitsPotential Benefits10.4 Cell Differentiation10.4 Cell DifferentiationPotential BenefitsPotential Benefits

– Stem cell research may lead to new ways to Stem cell research may lead to new ways to repair the cellular damage that results from heart repair the cellular damage that results from heart attack, stroke, and spinal cord injuries.attack, stroke, and spinal cord injuries.

– One example is the approach to reversing heart attack damage One example is the approach to reversing heart attack damage

illustrated below.illustrated below.

– Stem cell research may lead to new ways to Stem cell research may lead to new ways to repair the cellular damage that results from heart repair the cellular damage that results from heart attack, stroke, and spinal cord injuries.attack, stroke, and spinal cord injuries.

– One example is the approach to reversing heart attack damage One example is the approach to reversing heart attack damage

illustrated below.illustrated below.

10.4 Cell Differentiation10.4 Cell DifferentiationEthical Issues10.4 Cell Differentiation10.4 Cell DifferentiationEthical Issues

– Most techniques for harvesting, or Most techniques for harvesting, or gathering, embryonic stem cells cause gathering, embryonic stem cells cause destruction of the embryo.destruction of the embryo.

– Government funding of embryonic stem Government funding of embryonic stem cell research is an important political issue.cell research is an important political issue.

– Groups seeking to protect embryos Groups seeking to protect embryos oppose such research as unethical.oppose such research as unethical.

– Other groups support this research as Other groups support this research as essential to saving human lives and so view it essential to saving human lives and so view it as unethical to restrict the research.as unethical to restrict the research.

– Most techniques for harvesting, or Most techniques for harvesting, or gathering, embryonic stem cells cause gathering, embryonic stem cells cause destruction of the embryo.destruction of the embryo.

– Government funding of embryonic stem Government funding of embryonic stem cell research is an important political issue.cell research is an important political issue.

– Groups seeking to protect embryos Groups seeking to protect embryos oppose such research as unethical.oppose such research as unethical.

– Other groups support this research as Other groups support this research as essential to saving human lives and so view it essential to saving human lives and so view it as unethical to restrict the research.as unethical to restrict the research.

https://www.youtube.com/watch?v=27skh7prkN0

https://www.youtube.com/watch?v=27skh7prkN0

10.5 Asexual Reproduction 10.5 Asexual Reproduction Cell Division and ReproductionCell Division and Reproduction10.5 Asexual Reproduction 10.5 Asexual Reproduction Cell Division and ReproductionCell Division and Reproduction

How do asexual and sexual reproduction How do asexual and sexual reproduction compare?compare?

– The production of genetically identical The production of genetically identical offspring from a single parent is known as asexual offspring from a single parent is known as asexual reproduction.reproduction.

– Offspring produced by sexual reproduction Offspring produced by sexual reproduction inherit some of their genetic information from each inherit some of their genetic information from each parent.parent.

How do asexual and sexual reproduction How do asexual and sexual reproduction compare?compare?

– The production of genetically identical The production of genetically identical offspring from a single parent is known as asexual offspring from a single parent is known as asexual reproduction.reproduction.

– Offspring produced by sexual reproduction Offspring produced by sexual reproduction inherit some of their genetic information from each inherit some of their genetic information from each parent.parent.

10.5 Asexual Reproduction10.5 Asexual Reproduction10.5 Asexual Reproduction10.5 Asexual Reproduction

– In multicellular In multicellular organisms, cell division organisms, cell division leads to growth. It also leads to growth. It also enables an organism to enables an organism to repair and maintain its repair and maintain its body.body.

– In single-celled In single-celled organisms, cell division organisms, cell division is a form of reproduction.is a form of reproduction.

– In multicellular In multicellular organisms, cell division organisms, cell division leads to growth. It also leads to growth. It also enables an organism to enables an organism to repair and maintain its repair and maintain its body.body.

– In single-celled In single-celled organisms, cell division organisms, cell division is a form of reproduction.is a form of reproduction.

10.5 Asexual Reproduction10.5 Asexual Reproduction10.5 Asexual Reproduction10.5 Asexual Reproduction

– Asexual reproduction is reproduction that involves a Asexual reproduction is reproduction that involves a single parent producing an offspring. The offspring single parent producing an offspring. The offspring produced are, in most cases, genetically identical to the produced are, in most cases, genetically identical to the single cell that produced them. single cell that produced them.

– Asexual reproduction is a simple, efficient, and Asexual reproduction is a simple, efficient, and effective way for an organism to produce a large number of effective way for an organism to produce a large number of offspring.offspring.

– Both prokaryotic and eukaryotic single-celled Both prokaryotic and eukaryotic single-celled organisms and many multicellular organisms can reproduce organisms and many multicellular organisms can reproduce asexually.asexually.

– Asexual reproduction is reproduction that involves a Asexual reproduction is reproduction that involves a single parent producing an offspring. The offspring single parent producing an offspring. The offspring produced are, in most cases, genetically identical to the produced are, in most cases, genetically identical to the single cell that produced them. single cell that produced them.

– Asexual reproduction is a simple, efficient, and Asexual reproduction is a simple, efficient, and effective way for an organism to produce a large number of effective way for an organism to produce a large number of offspring.offspring.

– Both prokaryotic and eukaryotic single-celled Both prokaryotic and eukaryotic single-celled organisms and many multicellular organisms can reproduce organisms and many multicellular organisms can reproduce asexually.asexually.

10.5 Asexual Reproduction10.5 Asexual ReproductionExamples of Asexual ReproductionExamples of Asexual Reproduction10.5 Asexual Reproduction10.5 Asexual ReproductionExamples of Asexual ReproductionExamples of Asexual Reproduction

–Bacteria Bacteria reproduce by reproduce by binary fission.binary fission.

–Kalanchoe plants Kalanchoe plants form plantletsform plantlets

–Hydras reproduce Hydras reproduce by budding.by budding.

–Bacteria Bacteria reproduce by reproduce by binary fission.binary fission.

–Kalanchoe plants Kalanchoe plants form plantletsform plantlets

–Hydras reproduce Hydras reproduce by budding.by budding.

Common types of Common types of asexualasexual

reproductionreproduction

Common types of Common types of asexualasexual

reproductionreproduction• Cloning Cloning

• Binary FissionBinary Fission

• BuddingBudding

• SporulationSporulation

• RegenerationRegeneration

• Vegetative PropagationVegetative Propagation

• Cloning Cloning

• Binary FissionBinary Fission

• BuddingBudding

• SporulationSporulation

• RegenerationRegeneration

• Vegetative PropagationVegetative Propagation

10.5 Asexual Reproduction10.5 Asexual ReproductionCloningCloning10.5 Asexual Reproduction10.5 Asexual ReproductionCloningCloning

• Cloning is the process of creating an Cloning is the process of creating an identical copy of something.identical copy of something.

• Cloning collectively refers to processes Cloning collectively refers to processes used to create copies of DNA fragments used to create copies of DNA fragments (molecular cloning), cells (cell cloning), (molecular cloning), cells (cell cloning), or organisms. or organisms.

• The term also encompasses situations The term also encompasses situations whereby organisms reproduce whereby organisms reproduce asexually… this is common in unicellular asexually… this is common in unicellular organisms, plants and some insects.organisms, plants and some insects.

• Cloning is the process of creating an Cloning is the process of creating an identical copy of something.identical copy of something.

• Cloning collectively refers to processes Cloning collectively refers to processes used to create copies of DNA fragments used to create copies of DNA fragments (molecular cloning), cells (cell cloning), (molecular cloning), cells (cell cloning), or organisms. or organisms.

• The term also encompasses situations The term also encompasses situations whereby organisms reproduce whereby organisms reproduce asexually… this is common in unicellular asexually… this is common in unicellular organisms, plants and some insects.organisms, plants and some insects.

10.5 Asexual Reproduction10.5 Asexual ReproductionCloningCloning10.5 Asexual Reproduction10.5 Asexual ReproductionCloningCloning

• Organism cloning refers to the procedure Organism cloning refers to the procedure of creating a new multicellular organism, of creating a new multicellular organism, genetically identical to another. genetically identical to another.

• Cloning exists in nature in some animal Cloning exists in nature in some animal species and is referred to as species and is referred to as parthenogenesis.parthenogenesis.– An example of this is the whiptail An example of this is the whiptail

lizard: all of the individuals are female lizard: all of the individuals are female which produce offspring that are which produce offspring that are genetically identical to themselves. genetically identical to themselves.

• Organism cloning refers to the procedure Organism cloning refers to the procedure of creating a new multicellular organism, of creating a new multicellular organism, genetically identical to another. genetically identical to another.

• Cloning exists in nature in some animal Cloning exists in nature in some animal species and is referred to as species and is referred to as parthenogenesis.parthenogenesis.– An example of this is the whiptail An example of this is the whiptail

lizard: all of the individuals are female lizard: all of the individuals are female which produce offspring that are which produce offspring that are genetically identical to themselves. genetically identical to themselves.

First Cloned MammalFirst Cloned MammalFirst Cloned MammalFirst Cloned Mammal

• Dolly (July 1996–Dolly (July 1996–February 2003), an ewe, February 2003), an ewe, was the first mammal to was the first mammal to be cloned from an adult be cloned from an adult somatic (body) cell. somatic (body) cell.

• Dolly (July 1996–Dolly (July 1996–February 2003), an ewe, February 2003), an ewe, was the first mammal to was the first mammal to be cloned from an adult be cloned from an adult somatic (body) cell. somatic (body) cell.

http://upload.wikimedia.org/wikipedia/en/5/5f/Dolly_the_sheep2-thumb.jpg

10.5 Asexual Reproduction10.5 Asexual ReproductionAnimals that have been Animals that have been cloned:cloned:

10.5 Asexual Reproduction10.5 Asexual ReproductionAnimals that have been Animals that have been cloned:cloned:

• CarpCarp• CatCat• CattleCattle• DeerDeer• DogDog• FerretFerret• Fruit FlyFruit Fly• GoatGoat• GaurGaur• HorseHorse

• CarpCarp• CatCat• CattleCattle• DeerDeer• DogDog• FerretFerret• Fruit FlyFruit Fly• GoatGoat• GaurGaur• HorseHorse

• MiceMice• Mouflon (wild sheep)Mouflon (wild sheep)• MuleMule• PigPig• RabbitRabbit• RatRat• Rhesus MonkeyRhesus Monkey• SheepSheep• Water BuffaloWater Buffalo• WolfWolf

• MiceMice• Mouflon (wild sheep)Mouflon (wild sheep)• MuleMule• PigPig• RabbitRabbit• RatRat• Rhesus MonkeyRhesus Monkey• SheepSheep• Water BuffaloWater Buffalo• WolfWolf

10.5 Asexual Reproduction10.5 Asexual ReproductionBinary FissionBinary Fission10.5 Asexual Reproduction10.5 Asexual ReproductionBinary FissionBinary Fission

• Simplest type of asexual reproduction.Simplest type of asexual reproduction.

• A one-celled organism divides by mitosis A one-celled organism divides by mitosis to form two daughter cells of equal size.to form two daughter cells of equal size.

• Both the nucleus and cytoplasm divide Both the nucleus and cytoplasm divide equally.equally.

• The chromosomes of the offspring are The chromosomes of the offspring are genetically identical to the parent.genetically identical to the parent.

• Simplest type of asexual reproduction.Simplest type of asexual reproduction.

• A one-celled organism divides by mitosis A one-celled organism divides by mitosis to form two daughter cells of equal size.to form two daughter cells of equal size.

• Both the nucleus and cytoplasm divide Both the nucleus and cytoplasm divide equally.equally.

• The chromosomes of the offspring are The chromosomes of the offspring are genetically identical to the parent.genetically identical to the parent.

10.5 Asexual Reproduction10.5 Asexual ReproductionBinary FissionBinary Fission10.5 Asexual Reproduction10.5 Asexual ReproductionBinary FissionBinary Fission

10.5 Asexual Reproduction10.5 Asexual ReproductionBuddingBudding10.5 Asexual Reproduction10.5 Asexual ReproductionBuddingBudding

• A new organism develops as an A new organism develops as an outgrowth of the parent.outgrowth of the parent.

• The new organism, called the bud, is a The new organism, called the bud, is a tiny duplicate of the parent organism.tiny duplicate of the parent organism.

• The nucleus divides equally and the The nucleus divides equally and the cytoplasm divides unequally.cytoplasm divides unequally.

• The bud and the parent may separate The bud and the parent may separate from each other or may remain together from each other or may remain together and form a colony.and form a colony.

• A new organism develops as an A new organism develops as an outgrowth of the parent.outgrowth of the parent.

• The new organism, called the bud, is a The new organism, called the bud, is a tiny duplicate of the parent organism.tiny duplicate of the parent organism.

• The nucleus divides equally and the The nucleus divides equally and the cytoplasm divides unequally.cytoplasm divides unequally.

• The bud and the parent may separate The bud and the parent may separate from each other or may remain together from each other or may remain together and form a colony.and form a colony.

10.5 Asexual Reproduction10.5 Asexual ReproductionBuddingBudding10.5 Asexual Reproduction10.5 Asexual ReproductionBuddingBudding• MulticellularMulticellular

organismorganism

(hydra)(hydra)

• MulticellularMulticellular

organismorganism

(hydra)(hydra)

10.5 Asexual Reproduction10.5 Asexual ReproductionBuddingBudding

10.5 Asexual Reproduction10.5 Asexual ReproductionBuddingBudding

• Budding occurringBudding occurring

in yeast.in yeast.

• Budding occurringBudding occurring

in yeast.in yeast.

10.5 Asexual Reproduction10.5 Asexual ReproductionSporulationSporulation10.5 Asexual Reproduction10.5 Asexual ReproductionSporulationSporulation

• Spores are specialized asexual Spores are specialized asexual reproductive cells that contain a nucleus reproductive cells that contain a nucleus and a small amount of cytoplasm.and a small amount of cytoplasm.

• Spores are surrounded by a tough Spores are surrounded by a tough protective coat that enable them to protective coat that enable them to survive in extreme heat or cold for long survive in extreme heat or cold for long periods of time.periods of time.

• When environmental conditions become When environmental conditions become favorable, each spore can develop into a favorable, each spore can develop into a new organism.new organism.

• Spores are specialized asexual Spores are specialized asexual reproductive cells that contain a nucleus reproductive cells that contain a nucleus and a small amount of cytoplasm.and a small amount of cytoplasm.

• Spores are surrounded by a tough Spores are surrounded by a tough protective coat that enable them to protective coat that enable them to survive in extreme heat or cold for long survive in extreme heat or cold for long periods of time.periods of time.

• When environmental conditions become When environmental conditions become favorable, each spore can develop into a favorable, each spore can develop into a new organism.new organism.

10.5 Asexual Reproduction10.5 Asexual ReproductionSporulationSporulation

10.5 Asexual Reproduction10.5 Asexual ReproductionSporulationSporulation

• Formation of spores occurs in bread molds, molds, Formation of spores occurs in bread molds, molds, mushrooms, mosses and ferns.mushrooms, mosses and ferns.

• Formation of spores occurs in bread molds, molds, Formation of spores occurs in bread molds, molds, mushrooms, mosses and ferns.mushrooms, mosses and ferns.

http://en.wikipedia.org/wiki/Image:Moldy_nectarines.jpg

10.5 Asexual Reproduction10.5 Asexual ReproductionRegenerationRegeneration


• The development of a new organism from The development of a new organism from a part of the parent organism.a part of the parent organism.

– Example: In starfish, a single arm can Example: In starfish, a single arm can develop into a new starfishdevelop into a new starfish

• Starfish eat oysters and oyster Starfish eat oysters and oyster fishermen once tried to kill starfish by fishermen once tried to kill starfish by cutting them into pieces. Instead of cutting them into pieces. Instead of dying, each starfish piece grew into a dying, each starfish piece grew into a new starfish.new starfish.

• The development of a new organism from The development of a new organism from a part of the parent organism.a part of the parent organism.

– Example: In starfish, a single arm can Example: In starfish, a single arm can develop into a new starfishdevelop into a new starfish

• Starfish eat oysters and oyster Starfish eat oysters and oyster fishermen once tried to kill starfish by fishermen once tried to kill starfish by cutting them into pieces. Instead of cutting them into pieces. Instead of dying, each starfish piece grew into a dying, each starfish piece grew into a new starfish.new starfish.

Regeneration of body of body from from one armone armRegeneration of body of body from from one armone arm

https://www.youtube.com/watch?v=f7cXeWxxfD4

https://www.youtube.com/watch?v=f7cXeWxxfD4

Regeneration of a body partRegeneration of a body partRegeneration of a body partRegeneration of a body part



• This can also mean the replacement This can also mean the replacement of lost body parts.of lost body parts.

• Regeneration of lost body parts Regeneration of lost body parts occurs mostly in invertebrates.occurs mostly in invertebrates.– Example: Lobsters are able to Example: Lobsters are able to

grow a new claw to replace one grow a new claw to replace one that has been lost.that has been lost.

– Other example: lizards can Other example: lizards can disconnect their tails when disconnect their tails when chased or grabbed by a predator. chased or grabbed by a predator. The tail will grow back.The tail will grow back.

• This can also mean the replacement This can also mean the replacement of lost body parts.of lost body parts.

• Regeneration of lost body parts Regeneration of lost body parts occurs mostly in invertebrates.occurs mostly in invertebrates.– Example: Lobsters are able to Example: Lobsters are able to

grow a new claw to replace one grow a new claw to replace one that has been lost.that has been lost.

– Other example: lizards can Other example: lizards can disconnect their tails when disconnect their tails when chased or grabbed by a predator. chased or grabbed by a predator. The tail will grow back.The tail will grow back.

10.5 Asexual Reproduction10.5 Asexual ReproductionVegetative propagationVegetative propagation


• A form of asexual plant reproduction.A form of asexual plant reproduction.• A part of a plant – a root, a stem, or a leaf, A part of a plant – a root, a stem, or a leaf,

grows into a whole new plant.grows into a whole new plant.• The new plant is genetically identical to the The new plant is genetically identical to the

parent plant.parent plant.• Seedless fruit and vegetables have to be Seedless fruit and vegetables have to be

reproduced by this method.reproduced by this method.

• Growers use this type of reproduction because Growers use this type of reproduction because it is fast, easy to use, cheap and usually very it is fast, easy to use, cheap and usually very

successfulsuccessful..

• A form of asexual plant reproduction.A form of asexual plant reproduction.• A part of a plant – a root, a stem, or a leaf, A part of a plant – a root, a stem, or a leaf,

grows into a whole new plant.grows into a whole new plant.• The new plant is genetically identical to the The new plant is genetically identical to the

parent plant.parent plant.• Seedless fruit and vegetables have to be Seedless fruit and vegetables have to be

reproduced by this method.reproduced by this method.

• Growers use this type of reproduction because Growers use this type of reproduction because it is fast, easy to use, cheap and usually very it is fast, easy to use, cheap and usually very

successfulsuccessful..



• Tubers – Underground Tubers – Underground stems that contain stems that contain stored food.stored food.

• White potatoes are White potatoes are tubers. The “eyes” of tubers. The “eyes” of the potato are buds, the potato are buds, which can develop into which can develop into a new plant.a new plant.

• Tubers – Underground Tubers – Underground stems that contain stems that contain stored food.stored food.

• White potatoes are White potatoes are tubers. The “eyes” of tubers. The “eyes” of the potato are buds, the potato are buds, which can develop into which can develop into a new plant.a new plant.

http://en.wikipedia.org/wiki/Image:Potato_EarlyRose_sprouts.jpg

10.5 Asexual Reproduction10.5 Asexual ReproductionVegetative PropagationVegetative Propagation

10.5 Asexual Reproduction10.5 Asexual ReproductionVegetative PropagationVegetative Propagation

• Runners – stems that Runners – stems that grow out over the grow out over the surface of the soil from surface of the soil from the exiting stem.the exiting stem.

• At points along the At points along the runner, new plants runner, new plants grow.grow.

• Runners occur in Runners occur in strawberries and some strawberries and some grasses.grasses.

• Runners – stems that Runners – stems that grow out over the grow out over the surface of the soil from surface of the soil from the exiting stem.the exiting stem.

• At points along the At points along the runner, new plants runner, new plants grow.grow.

• Runners occur in Runners occur in strawberries and some strawberries and some grasses.grasses.

10.5 Asexual Reproduction10.5 Asexual ReproductionNatural Vegetative Natural Vegetative PropagationPropagation


• Rhizomes – Long, Rhizomes – Long, modified stems that modified stems that grow horizontally grow horizontally under the soil.under the soil.

• New plants are New plants are produced at nodes produced at nodes along the stem.along the stem.

• Lawn grass, ferns, Lawn grass, ferns, and irises and irises reproduce by reproduce by rhizomes.rhizomes.

• Rhizomes – Long, Rhizomes – Long, modified stems that modified stems that grow horizontally grow horizontally under the soil.under the soil.

• New plants are New plants are produced at nodes produced at nodes along the stem.along the stem.

• Lawn grass, ferns, Lawn grass, ferns, and irises and irises reproduce by reproduce by rhizomes.rhizomes.



• Bulbs – Underground Bulbs – Underground stems specialized for stems specialized for food storage.food storage.

• The food is stored in The food is stored in the thick leaves of the the thick leaves of the bulb.bulb.

• Each bulb can develop Each bulb can develop into a new plant.into a new plant.

• Onions, garlic, tulips, Onions, garlic, tulips, and daffodils are bulbs.and daffodils are bulbs.

• Bulbs – Underground Bulbs – Underground stems specialized for stems specialized for food storage.food storage.

• The food is stored in The food is stored in the thick leaves of the the thick leaves of the bulb.bulb.

• Each bulb can develop Each bulb can develop into a new plant.into a new plant.

• Onions, garlic, tulips, Onions, garlic, tulips, and daffodils are bulbs.and daffodils are bulbs.

10.5 Asexual Reproduction10.5 Asexual Reproduction Natural VegetativeNatural VegetativePropagation: Spring BulbsPropagation: Spring Bulbs

10.5 Asexual Reproduction10.5 Asexual Reproduction Natural VegetativeNatural VegetativePropagation: Spring BulbsPropagation: Spring Bulbs

10.5 Asexual Reproduction10.5 Asexual ReproductionArtificial Vegetative Artificial Vegetative PropagationPropagation

10.5 Asexual Reproduction10.5 Asexual ReproductionArtificial Vegetative Artificial Vegetative PropagationPropagation• Occurs as a result of Occurs as a result of

human activity.human activity.• Cuttings – pieces of Cuttings – pieces of

roots, stems or roots, stems or leaves develop into leaves develop into new plants under new plants under proper conditions.proper conditions.

• Roses, sugar cane Roses, sugar cane and bananas are and bananas are propagated this way.propagated this way.

• Occurs as a result of Occurs as a result of human activity.human activity.

• Cuttings – pieces of Cuttings – pieces of roots, stems or roots, stems or leaves develop into leaves develop into new plants under new plants under proper conditions.proper conditions.

• Roses, sugar cane Roses, sugar cane and bananas are and bananas are propagated this way.propagated this way.

Artificial Vegetative Artificial Vegetative PropagationPropagationArtificial Vegetative Artificial Vegetative PropagationPropagation



• Grafting – a cutting Grafting – a cutting from one plant, called from one plant, called the scion, is attached to the scion, is attached to the main body of a the main body of a rooted plant, the stockrooted plant, the stock

• The scion keeps its own The scion keeps its own identity.identity.

• Seedless oranges and Seedless oranges and grapes are propagated grapes are propagated by grafting.by grafting.

• Grafting – a cutting Grafting – a cutting from one plant, called from one plant, called the scion, is attached to the scion, is attached to the main body of a the main body of a rooted plant, the stockrooted plant, the stock

• The scion keeps its own The scion keeps its own identity.identity.

• Seedless oranges and Seedless oranges and grapes are propagated grapes are propagated by grafting.by grafting.

Asexual Reproduction: Asexual Reproduction: Pros & ConsPros & ConsAsexual Reproduction: Asexual Reproduction: Pros & ConsPros & Cons

Pros:Pros:• Rapid population growthRapid population growth• Ability to reproduce Ability to reproduce

without a partnerwithout a partner• Genetically identical Genetically identical

offspring do great in a offspring do great in a stable environmentstable environment

• Reduce chance of Reduce chance of mutationmutation

Pros:Pros:• Rapid population growthRapid population growth• Ability to reproduce Ability to reproduce

without a partnerwithout a partner• Genetically identical Genetically identical

offspring do great in a offspring do great in a stable environmentstable environment

• Reduce chance of Reduce chance of mutationmutation

Cons:Cons:• Genetically identically Genetically identically

offspring: if they can not offspring: if they can not meet the needs of a meet the needs of a changing env.– changing env.– population will die.population will die.

Cons:Cons:• Genetically identically Genetically identically

offspring: if they can not offspring: if they can not meet the needs of a meet the needs of a changing env.– changing env.– population will die.population will die.

Sexual ReproductionSexual ReproductionSexual ReproductionSexual Reproduction

– In sexual reproduction, In sexual reproduction, offspring are produced by the fusion offspring are produced by the fusion of two sex cells – one from each of of two sex cells – one from each of two parents. These fuse into a two parents. These fuse into a single cell before the offspring can single cell before the offspring can grow.grow.

– The offspring produced inherit The offspring produced inherit some genetic information from both some genetic information from both parents.parents.

– Most animals and plants, and Most animals and plants, and many single-celled organisms, many single-celled organisms, reproduce sexually.reproduce sexually.

– In sexual reproduction, In sexual reproduction, offspring are produced by the fusion offspring are produced by the fusion of two sex cells – one from each of of two sex cells – one from each of two parents. These fuse into a two parents. These fuse into a single cell before the offspring can single cell before the offspring can grow.grow.

– The offspring produced inherit The offspring produced inherit some genetic information from both some genetic information from both parents.parents.

– Most animals and plants, and Most animals and plants, and many single-celled organisms, many single-celled organisms, reproduce sexually.reproduce sexually.

10.5 Asexual Reproduction10.5 Asexual ReproductionComparing Sexual and Asexual Comparing Sexual and Asexual ReproductionReproduction

10.5 Asexual Reproduction10.5 Asexual ReproductionComparing Sexual and Asexual Comparing Sexual and Asexual ReproductionReproduction

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