Section 2 Objectives – page 201
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Transcript of Section 2 Objectives – page 201
Section Objectives
• Relate the function of a cell to its organization in tissues, organs, and organ systems.
• Sequence the events of the cell cycle.
Cell Size LimitationsCell Size Limitations
• The cells that make up a multicellular organism come in a wide variety of sizes and shapes.
• Considering this wide range of cells sizes, why then can’t most organisms be just one giant cell?
Diffusion limits cell sizeDiffusion limits cell size
• Although diffusion is a fast and efficient process over short distances, ___________________________________________________________________________________________________________.
• Because of the slow rate of diffusion, organisms can’t be just ________________.
DNA limits cell sizeDNA limits cell size
• The cell cannot survive unless there is ___________________________________of the cell.
• In many large cells, ______________________________________is present.
• ____________________________________ensure that cell activities are carried out quickly and efficiently.
Surface area-to-volume ratioSurface area-to-volume ratio
• As a __________increases, its ______________increases much faster than its surface area.
Surface area = 6 mm2 Volume = 1 mm3
Surface area = 24 mm2 Volume = 8 mm3
1 mm 1 mm
1 mm
2 mm 2 mm
2 mm
4 mm 4 mm
4 mm
Surface area = 6 mm2 Volume = 1 mm3
Surface area = 24 mm2 Volume = 8 mm3
1 mm 1 mm
1 mm
2 mm 2 mm
2 mm
4 mm 4 mm
4 mm
• If cell size________, the cell would require ____times more _________and would have ____ times more ____________ to excrete.
Surface area-to-volume ratioSurface area-to-volume ratio
• The___________________, however, would increase by a factor of only_________.
Surface area-to-volume ratioSurface area-to-volume ratio
Surface area = 6 mm2 Volume = 1 mm3
Surface area = 24 mm2 Volume = 8 mm3
1 mm 1 mm
1 mm
2 mm 2 mm
2 mm
4 mm 4 mm
4 mm
Surface area-to-volume ratioSurface area-to-volume ratio
Surface area = 6 mm2 Volume = 1 mm3
Surface area = 24 mm2 Volume = 8 mm3
1 mm 1 mm
1 mm
2 mm 2 mm
2 mm
4 mm 4 mm
4 mm
• The cell would either ______________or be ___________________from the buildup of waste products.
Cell ReproductionCell Reproduction
• Cell division is the process by which _______________________________________________________________________.
• Cell division results in ________________________________________________________________________________________.
The discovery of chromosomesThe discovery of chromosomes
• Structures, which_____________________
• ___________________________________, are called chromosomes.
• Chromosomes are the _________________
• _______________________________________________________________________.
• Accurate transmission of chromosomes during cell division is__________________.
The structure of eukaryotic chromosomesThe structure of eukaryotic chromosomes
Centromere
Chromosome
Sister chromatids
Supercoil within chromosome
Continued coiling within supercoil
Histone H1
Nucleosome
DNA
The Cell CycleThe Cell Cycle• The cell cycle is ______________________
• ___________________________________.
• The __________of a cell’s life is spent in the _______________period known as ______________. Interphase
The Cell CycleThe Cell Cycle
• Following interphase, a cell enters its period of ______________________called mitosis.
• Following mitosis,_______________________________, separating the two daughter cells.Mitosis
Interphase: A Busy TimeInterphase: A Busy Time
• Interphase, the busiest phase of the cell cycle, is_____________________________.
DNA synthesis and replication Centrioles replicate;
cell prepares for division
Rapid growth and metabolic activity
Interphase
Interphase: A Busy TimeInterphase: A Busy Time
• During the first part, the___________________________________________________.
Rapid growth
and metabolic activity
Interphase
Interphase: A Busy TimeInterphase: A Busy Time
• In the next part of interphase,_______________________________________________.
DNA synthesis and replication
Interphase
Interphase: A Busy TimeInterphase: A Busy Time
• After the chromosomes have been duplicated, the cell enters another shorter growth period in which____________________________________________________________________________________________________________________________.
Centrioles replicate; cell prepares for division
Interphase
The Phases of MitosisThe Phases of Mitosis
• The four phases of mitosis are:
• __________________________
• __________________________
• __________________________
• __________________________
Prophase: The first phase of mitosisProphase: The first phase of mitosis
• During prophase,_________________________________________________________.
Spindle fibers
Disappearing nuclear envelope
Doubled chromosome
Prophase: The first phase of mitosisProphase: The first phase of mitosis
• The ______________________________
• ____________are called sister chromatids.
Sister chromatids
Prophase: The first phase of mitosisProphase: The first phase of mitosis
• Sister chromatids are ______________by a structure called a centromere, which plays a role in chromosome ___________
during mitosis.
Centromere
Metaphase: The second stage of mitosisMetaphase: The second stage of mitosis
• During metaphase, the chromosomes_____________________________________________________________________________.
Centromere
Sister chromatids
Anaphase: The third phase of mitosisAnaphase: The third phase of mitosis
• During anaphase, the ________________and the sister chromatids are ______________to opposite poles of the cell.
Telophase: The fourth phase of mitosisTelophase: The fourth phase of mitosis
• During telophase, ___________________are formed. The cells _______________as the cell cycle proceeds into the next interphase.
Nuclear envelope reappears
Two daughter cells are formed
CytokinesisCytokinesis
• Following telophase, the _________________________in a process called cytokinesis.
• Cytokinesis differs between plants and animals.
• Toward the end of telophase in__________, the plasma membrane ________________in along the equator.
CytokinesisCytokinesis
• Plant cells have a rigid cell wall, so the plasma membrane ___________________in.
• A structure known as the ______________is laid down across the cell’s equator.
• A ____________________around each cell, and new cell walls form on each side of the _____________until separation is complete.
Results of MitosisResults of Mitosis
• When mitosis is complete, _________
• _______________remain as ________ cells.• In multicellular organisms, cell growth and
reproduction result in _____________________________________________________to perform a specific function.
Results of MitosisResults of Mitosis
• Tissues organize in various combinations to form organs that ___________________________________________within the organism.
• ____________________________that work together form an organ system.