Chapter Menu Lesson 1:The Cell Cycle and Cell DivisionThe Cell Cycle and Cell Division Lesson...

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Lesson 1:The Cell Cycle and Cell Division

Lesson 2: Levels of Organization

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cell cycle

interphase

centromere

mitosis

cytokinesis

prophase

metaphase

2.1 The Cell Cycle and Cell Division

anaphase

telophase

daughter cell

cell plate

homologous chromosome

sister chromatid

The Cell CycleCell Cycle

• Life cycle of cells

2.1 The Cell Cycle and Cell Division

• Includes phasesphases of growth, development, and reproduction (interphase, mitosis, and cytokinesis)

Phases of the Cell Cycle

• The phase of the cell cycle when a cell is preparing to reproduce is called interphaseinterphase.

2.1 The Cell Cycle and Cell Division

• The phase when a eukaryotic cell reproduces is called mitoticmitotic phase.

Phases of the Cell Cycle (cont.)

2.1 The Cell Cycle and Cell Division

Length of a Cell Cycle

• LengthLength of time for cell cycle is different for different types of organisms and cells

2.1 The Cell Cycle and Cell Division

• During earliest stages of animal growth, cell cycle can repeat quickly

• Dependent on the type of organism and type of cell

• Cell cycles repeat quickly in early stages of animal growth

Characteristics of Interphase

• Cell performs specific functionsfunctions during interphase.

2.1 The Cell Cycle and Cell Division

– Stomach cells might produce substances that aid in digestion.

– Plant cells might perform cellular respiration.

Characteristics of Interphase (cont.)

• During interphase, the chromosomes in a nucleus are so thin they cannot be observed with a light microscope.

2.1 The Cell Cycle and Cell Division

• For each chromosome in one set of chromosomes, there is a similar chromosome in the other set of chromosomes.

• Each pair of similar chromosomes is called a pair of homologous chromosomes.

Phases of Interphase

• There are three phases—G1, S, and G2.

2.1 The Cell Cycle and Cell Division

• G1G1: cell grows and carries out its usual cellular functions

– Some cells remain in G1 and do not reproducereproduce, such as muscle cells, red blood cells, and some nerve cells.

Phases of Interphase (cont.)

• S phase: the homologoushomologous chromosomes in a cell’s nucleus continue growth but also replicate

2.1 The Cell Cycle and Cell Division

• Sister chromatidSister chromatid: copy of chromosome ensures that the new cell is identicalidentical

Phases of Interphase (cont.)

• G2G2 phase: continues growth and replication but also replicates organellesorganelles

2.1 The Cell Cycle and Cell Division

• Mitochondria and chloroplasts: have own DNA and can duplicate themselves

MitosisMitosis

• Process in which the nucleus divides

• CytokinesisCytokinesis: process in which the cytoplasm divides

2.1 The Cell Cycle and Cell Division

• New cells made by mitosis and cell division will replace old worn-out dead cells.

– Also produce most cells in a many-celledmany-celled organism.

Mitosis

Mitosis• A different type of cell division produces spermsperm and

eggegg cells.

2.1 The Cell Cycle and Cell Division

• There are fourfour phases of mitosis.

Mitosis

Phases of Mitosis• ProphaseProphase: first phase of mitosis in which the DNA twists

into tight coils and the nucleus membrane breaks apart

2.1 The Cell Cycle and Cell Division

• Replicated DNA condenses into chromosomes.

• Nuclear membrane disappears?

Phases of Mitosis (cont.)

• MetaphaseMetaphase: second phase of mitosis in which the replicated chromosomes move to middle of cell and line up end-to-end

2.1 The Cell Cycle and Cell Division

• Chromosomes align at the middle of the cell.

Phases of Mitosis (cont.)

• AnaphaseAnaphase: third phase of mitosis in which the sister chromatids separate and the centromeres divide

2.1 The Cell Cycle and Cell Division

• Centromeres divide.

• Sister chromatids separate.

Phases of Mitosis (cont.)

• TelophaseTelophase: final phase of mitosis in which a new membrane forms around each set of chromosomes

2.1 The Cell Cycle and Cell Division

• Nuclear membranes form.

Dividing the Cell’s Components• During cytokinesiscytokinesis the final stage of cell division, the cytoplasm and its components divide to form

two identical daughter cellsdaughter cells.

– At the start of cytokinesis, the cell membrane pinchespinches inward.

• A disc, or cell platecell plate, forms between the two new nuclei that are dividing.

– This becomes the cell membranemembrane, which builds the new cell walls.

2.1 The Cell Cycle and Cell Division

Results of Cell Division• After mitosis and cell division, the original cell—the

parent cell—no longer exists.

• The chromosomes of twotwo daughter cells are identical in numbernumber and type to each other and to the parent cell.

• All the cells in the body have identical chromosomes except sperm and egg egg cells.

2.1 The Cell Cycle and Cell Division

Lesson 1 Review

When a cell is preparing to reproduce, what phase of the cell cycle is it in?

A S phase

B prophase

C interphase

D mitosis

2.1 The Cell Cycle and Cell Division

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1. A

2. B

3. C

4. D

Lesson 1 Review

In which phase does the nucleus divide?

A G2

B mitosis

C cytokinesis

D cell division

2.1 The Cell Cycle and Cell Division

0% 0%0%0%

1. A

2. B

3. C

4. D

Lesson 1 Review

In which type of cell would you expect to see a cell plate form?

A plant cell

B animal cell

C stomach cell

D parent cell

2.1 The Cell Cycle and Cell Division

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1. A

2. B

3. C

4. D

End of Lesson 1

cell differentiation

stem cell

tissue

organ

organ system

2.2 Levels of Organization

Single-Celled Organisms

• Carry out all the functions needed for their survival, including:

• Need to be organized

2.2 Levels of Organization

– obtaining nutrients

– waste removal

– movement

– protection

– reproduction

Prokaryotes

– Still have structures with specific functions

– Same processes that occur in eukaryotic organelles happen along specialized membranes in bacteria

• Single-celled organisms that do not have nuclei or other organelles, such as bacteria

2.2 Levels of Organization

Eukaryotes

– Include amoeba and some fungi

– Are more complex than prokaryotes

– Have a nucleus and membrane-bound organelles

• Protists are single-celled eukaryotes

2.2 Levels of Organization

Eukaryotes (cont.)

– Single-celled: exist alone and must do everything needed for their survival within the single cell

– Multicellular eukaryotes: rely on one another and cannot survive alone

• Single-celled eukaryotes are more complex than cells in multicellular eukaryotes.

2.2 Levels of Organization

Multicellular Organisms

• Multicellular organisms require organization.

2.2 Levels of Organization

• They have many cells and usually have more than one type of cell.

How do animal and plant cells work?

Cell Differentiation

• Process in which cells become different types of cells

2.2 Levels of Organization

• Differentiated cells: specialized structures and shapes for specific functions, such as liver cells or brain cells

• Once most human cells differentiate, they cannot become any other type of cell.

Cell Specialization

Stem Cells• Cells that can become different types

of cells

2.2 Levels of Organization

Tissues• Groups of similar cells that work together and perform

a function

2.2 Levels of Organization

Tissues (cont.)

2.2 Levels of Organization

Organs• A group of similar tissues that work together to perform

a function

2.2 Levels of Organization

Organs (cont.)

• Human organs include the heart, lungs, brain, and muscles.

2.2 Levels of Organization

• Plant organs have organs, such as leaves, that store nutrients, exchange gases, transport water or nutrients, or perform photosynthesis.

Organ Systems• One or more organs that work together and perform

one or more functions

2.2 Levels of Organization

Human Organ Systems

2.2 Levels of Organization

Organ Systems (cont.)

Human Organ Systems

2.2 Levels of Organization

Organ Systems (cont.)

Human Organ Systems

2.2 Levels of Organization

Organ Systems (cont.)

Organisms• The most complex unit of living things is a multicellular

organism.

• Multicellular organisms usually have many organ systems.

• Each organ system has its own function but is dependent on other organ systems.

2.2 Levels of Organization

Organisms (cont.)

2.2 Levels of Organization

Lesson 2 Review

Where do bacteria carry out the processes that occur in the organelles of eukaryotes?

A nucleus

B chloroplast

C smooth ER

D specialized membranes

2.2 Levels of Organization

0% 0%0%0%

1. A

2. B

3. C

4. D

Lesson 2 Review

What are undifferentiated cells called?

A stem cells

B tissues

C prokaryotes

D liver cells

2.2 Levels of Organization

0% 0%0%0%

1. A

2. B

3. C

4. D

Lesson 2 Review

What organ system produces hormones that control body functions?

A skeletal

B lymphatic

C nervous

D endocrine

2.2 Levels of Organization

0% 0%0%0%

1. A

2. B

3. C

4. D

End of Lesson 2

Chapter Resources Menu

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Chapter Assessment

California Standards Practice

Concepts in Motion

Image Bank

Science Online

Interactive Table

Virtual Lab

BrainPOP

Each chromosome in one set of chromosomes has a similar chromosome in the other set of chromosomes. What is a pair of similar chromosomes called?

A sister chromosomes

B homologous chromosomes

C daughter chromosomes

D parent chromosomes

Chapter Assessment 1

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1. A

2. B

3. C

4. D

Sister chromatids are held together at what region of the chromatids?

A the ends

B the centromere

C the cell plate

D G1

Chapter Assessment 2

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1. A

2. B

3. C

4. D

When do the sister chromatids of each replicated chromosome begin to separate?

A prophase

B metaphase

C anaphase

D telophase

Chapter Assessment 3

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1. A

2. B

3. C

4. D

By what process do cells become different types of cells with specialized structures and functions?

A cell division

B mitosis

C cell differentiation

D the cell cycle

Chapter Assessment 4

0% 0%0%0%

1. A

2. B

3. C

4. D

What does a leaf have in common with a bicep muscle?

A both perform the same function

B both are at the same level of organization

C both are tissues

D both are eukaryotes

Chapter Assessment 5

0% 0%0%0%

1. A

2. B

3. C

4. D

What happens during cytokinesis?

A the nucleus divides

B the cytoplasm divides

C chromosomes are replicated

D growth and cellular functions

CA Standards Practice 1

SCI 1.e

0% 0%0%0%

1. A

2. B

3. C

4. D

What is the first phase of mitosis?

A interphase

B G1

C prophase

D cell division

CA Standards Practice 2

SCI 1.e

0% 0%0%0%

1. A

2. B

3. C

4. D

What is the most complex level of organization?

A organism

B organ system

C cells in eukaryotes

D tissues

CA Standards Practice 3

SCI 5.a

0% 0%0%0%

1. A

2. B

3. C

4. D

What is a group of cells that work together to perform a function called?

A organ

B organ system

C organism

D tissue

CA Standards Practice 4

SCI 5.a

0% 0%0%0%

1. A

2. B

3. C

4. D

What is a stem cell?

A a leaf cell

B a differentiated cell

C an undifferentiated cell

D a fertilized egg

CA Standards Practice 5

SCI 1.f

0% 0%0%0%

1. A

2. B

3. C

4. D

Concepts in Motion 1

Concepts in Motion 2

Image Bank

Interactive Table

Interactive Table

Interactive Table

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