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Chapter 5: Cell Growth and Division
Unit 2: Cells Chapter 5: Cell Growth and Division
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Chapter 4: Cell Growth and Division
UNIT 2: Cells Chapter 4: Cell Growth and Division I. The Cell Cycle has four main stages (5.1) A. The _____ ______is a regular pattern of ______, _____________, and ___ ________ in ___________ cells
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1. Originally divided into two stages (observations were
1. Originally divided into two stages (observations were limited by microscopes at the time) a. __________- cell appeared to be at rest b. ________- cell dividing 2. Improved techniques and tools later allowed scientist to identify 4 distinct stages
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a. Gap 1 (G1) - cell carries out normal functions
1). ______ increases in ______ 2). _________ increase in numbers
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b. ___________ (S) - Cell makes copy of its nuclear ______.
1). __________ means “the combining of parts to make a whole. 2). By end of S stage, cell nucleus contains _____complete sets of ______
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c. Gap 2 (G2) - Cells continue to carry out normal functions
1).Additional _______ occurs 2). Critical ________ (before cell goes through mitosis cell must be adequate size, undamaged DNA)
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d. _________ (M) - Includes two processes
1). Mitosis - _________ of cell ________ and its contents 2). __________ - Process that ________ the cell __________. Two identical daughter cells produced
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B. Cells divide at different rates
1. Rates of cell division vary widely a. ____________ cells typically divide much faster than____________cells b. Rate at which cells divide linked to body’s _______ for those cells.
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2. In human cells, S, G2, and M stages together usually take about ____________
a. Length of G1 stage differs most for different cell types b. Rate of cell division greater in _________ and _________
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C. Cell size is limited 1. Cells have upper and lower size limits a. Must be ______ enough to “hold” everything b. Upper limit due to ratio of cell ___________to _________
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1). Oxygen, nutrients, and wastes move
1).Oxygen, nutrients, and wastes move across the __________________(surface of cell) 2). As cell grows, its surface area (cell membrane) does not grow as fast as volume- too small for adequate ____________________
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2. To maintain suitable cell size, growth and cell division must be ____________.
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II. Mitosis and Cytokinesis (5.2)
A. Chromosomes condense at start of mitosis 1. _____________ - one long continuous thread of _______ a. Consists of numerous ________ b. You have ____ chromosomes
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c. Must be ___________ to fit into cell nucleus
1). ____ wraps around proteins called _______ 2). When loosely condensed called _________
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d. Chromosome looks like “___” (each half is identical DNA- called a __________)
e. ______chromatids held together by _________
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f. ________ - found at ends of DNA molecules and prevent DNA from coming apart
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B. Mitosis and cytokinesis produce two genetically ________
B. Mitosis and cytokinesis produce two genetically ________ daughter cells 1. ________ - important role in preparing cell to divide (2 sets of _____ and are ______ enough) 2. Mitosis - divides cell’s ________ into two genetically ________ nuclei, each with its own single, full set of _______ Two genetically identical nuclei
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3. 4 main phases of Mitosis a. _________ - DNA condenses into tightly coiled _____________. Nuclear envelope breaks down. _________ move to poles and ________ fibers form Centrioles chromosomes Nuclear envelope Spindle fibers
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b. ___________ - Spindle fibers attach to each __________
b. ___________ - Spindle fibers attach to each __________. Chromosomes align along cell _______ (middle) centromere What is the name of this structure?
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c. _________ - Chromatids ________ to opposite sides of cell
chromotids
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d. _________ - Nuclear _________ starts to. form
d. _________ - Nuclear _________ starts to form. Chromosomes begin to uncoil and spindle fibers fall apart
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4. ___________ - division of cytoplasm
4. ___________ - division of cytoplasm. Different in ______ and _______cells.
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III. Regulation of Cell Cycle (5.3)
A. ________ and _______ factors regulate cell division 1. External factors a. Include physical and chemical factors b. Once a cell touches another cell it ______ dividing c. Many cells release chemical signals (_____________) that trigger cell growth.
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2. Internal factors a. External factors trigger internal factors that affect cell cycle b. Two of the most important internal factors are kinases and cyclins
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3. __________ - programmed cell ______ (signals activate genes producing self-destructive _______
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B. Cell division is uncontrolled in _______.
1. Cancer - common name for class or diseases characterized by ____________ cell division a. Form from disorganized clumps called________
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b. Two types of tumors 1). ________ - cancer cells typically remain __________ together.
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2). _________ - Some cell break away (or ____________) from the tumor and spread through body
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2. Cancer cells come from normal cells that have suffered damage to ________ that make ________ involved in _____________ Brain cancer cells
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a. damage from _________,________, _________, _________ radiation
b. _____________ - Substances know to cause cancer
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c. Cancer can be treated with both ____________ and ___________
c. Cancer can be treated with both ____________ and ___________.(these typically kill both cancerous and healthy cells)
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IV. Asexual Reproduction (5.4)
A. _______________is similar in function to mitosis 1. Reproduction occurs in two ways (______ and ______ reproduction)
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a. ______ reproduction - joining of two specialized cells (_________ - egg and sperm), one from each parent 1). Offspring are genetically _________ 2). Mixture of _______ from both parents
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b. __________ reproduction - creation of offspring from a single parent. Offspring genetically ____________
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2. Binary fission - asexual reproduction of single-celled organism
a. Occurs in _____________ b. binary fission and _________ have similar results
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B. Advantages and Disadvantages of Asexual reproduction
1.In environments that don’t change, _________ may be better. If they are well suited to environment may be more efficient 2. In changing environments __________ reproduction produces genetic ______ which raises chances for survival
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V. Multicellular Life (5.5)
A. Multicellular organisms depend on _____________ among different cell types. 1. Cells ____________ and ______________ in groups that form increasingly large, more complex structures
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a. CELLS → _______ → ________ → ________ __________
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b. ________ - group or cells that _____ _______to perform a particular function
c. ______ - group of _______ that work together to perform specific function or related functions
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d. Organ system - _______ that carry out similar ___________
1). Organ systems work together to maintain ________________ 2). Occurs in ______ and ________
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B. Specialized cells perform specific functions
1. Cell _____________ - process by which unspecialized cells develop into their mature _____ and __________ a. Every cell in body has full set of ____ b. Cells only use certain ______ and become________(ie. bone cells, mucscle cells, nerver cells, etc.)
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C. Stem cells can develop into different cell types
1. ___________- unique type of body cell a. Can divide and renew themselves for long periods of time b. Remain ___________ in form c. Develop into a variety of specialized cell types
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2. Stem cells can be catorgorized by their ability or potential to develop into differentiated cell types and different tissues.
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3. _______ Stem Cells - partially _____________ cells located among the specialized cells or many organs and tissues 4. _________ Stem Cells - come from donated embryos grown in a clinic
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5. Research and Treatment Hope
a. Stem cells have long been used to treat ________ and _______ b. Might be used to repair damaged ______ c. Used to cure diseases (i.e. _______)
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