objectives_unit_2_ch_14_2013.doc | |
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Unit 2 - Cellular Reproduction (Mitosis and Meiosis)
Objectives 1 & 3-4
The Cell Cycle - P. 460
•this cycle is how our cells (eukaryotic) reproduce themselves through two main
stages:
1. interphase - the growth phase
2. mitosis / cytokinesis - the division phase
1. interphase
includes making new molecules (increasing the cells volume & mass)& DNA is copied or replicated
interphase happens in 3 parts or phases:
•G1 (gap 1) –rapid growth and metabolic activities (chemical reactions) to get ready for celldivision
•S (synthesis) - DNA is replicated
•G2(gap2) - cell prepares for cell division (centrioles replicate)
interphase is the longest part of the cell cycle but varies for different types of cells (see fig. 14.3 page 461)
2. Division Phase
•two processes:
1. mitosis - division of the nucleus (genetic info)
2. cytokinesis - division of the cytoplasm
•unlike interphase, these are the shortest events in the Cell Cycle but they also vary for different types of cells (fig 14.3, p. 461)
The Cell Cycle - P. 460
•this cycle is how our cells (eukaryotic) reproduce themselves through two main
stages:
1. interphase - the growth phase
2. mitosis / cytokinesis - the division phase
1. interphase
includes making new molecules (increasing the cells volume & mass)& DNA is copied or replicated
interphase happens in 3 parts or phases:
•G1 (gap 1) –rapid growth and metabolic activities (chemical reactions) to get ready for celldivision
•S (synthesis) - DNA is replicated
•G2(gap2) - cell prepares for cell division (centrioles replicate)
interphase is the longest part of the cell cycle but varies for different types of cells (see fig. 14.3 page 461)
2. Division Phase
•two processes:
1. mitosis - division of the nucleus (genetic info)
2. cytokinesis - division of the cytoplasm
•unlike interphase, these are the shortest events in the Cell Cycle but they also vary for different types of cells (fig 14.3, p. 461)
Mitosis Stage 1 - Prophase
•chromatin coils to form thick, condensed chromosomes
•nuclear membrane and nucleolus disappear
•centrioles move to opposite poles of the cell
•spindle fibers start to form between the 2 centrioles
•chromatin coils to form thick, condensed chromosomes
•nuclear membrane and nucleolus disappear
•centrioles move to opposite poles of the cell
•spindle fibers start to form between the 2 centrioles
Mitosis Stage 2 - Metaphase
•spindle fibers attach to the centromere of each duplicated chromosome
•Centrioles have reached opposite poles
•duplicated chromosomes line up along the equator of the cell (a spindle fiber from one pole is attached to one sister chromatid of the duplicated chromosome and a spindle fiber from the opposite pole is attached to the other sister
chromatid
- Why?)
•spindle fibers attach to the centromere of each duplicated chromosome
•Centrioles have reached opposite poles
•duplicated chromosomes line up along the equator of the cell (a spindle fiber from one pole is attached to one sister chromatid of the duplicated chromosome and a spindle fiber from the opposite pole is attached to the other sister
chromatid
- Why?)
Mitosis Stage 3 - Anaphase
• the centromere hlding each sister chromatid splits apart
•the chromatids get pulled to opposite poles by shortening spindle fibers
•cytokinesis begins
• the centromere hlding each sister chromatid splits apart
•the chromatids get pulled to opposite poles by shortening spindle fibers
•cytokinesis begins
Mitosis Stage 4 - Telophase
•begins when the chromatids have reached the two opposite poles of the cell
•now the chromatids are called single unduplicated chromosomes
•chromosomes begin to unwind
•spindle fibers disappear
•nuclear membranes reform around each new set of chromosomes
•cytokinesis finishes
•begins when the chromatids have reached the two opposite poles of the cell
•now the chromatids are called single unduplicated chromosomes
•chromosomes begin to unwind
•spindle fibers disappear
•nuclear membranes reform around each new set of chromosomes
•cytokinesis finishes
•Cytokinesis
- the separation of the cytoplasm of the cell (usually) after the stages of mitosis have split the genetic info. (Fig. 14.8 and Fig. 14.9 page 465)
• Animal cell - furrow forms to pinch cell in half
•Plant cell - cell plate forms to pinch cell in half (cell wall)
• When this process is complete, two new daughter cells have been formed from the one parent cell and are identical copies of the original parent cell
•The daughter cells contain the exact same genetic info (the
same # of chromosomes)
- the separation of the cytoplasm of the cell (usually) after the stages of mitosis have split the genetic info. (Fig. 14.8 and Fig. 14.9 page 465)
• Animal cell - furrow forms to pinch cell in half
•Plant cell - cell plate forms to pinch cell in half (cell wall)
• When this process is complete, two new daughter cells have been formed from the one parent cell and are identical copies of the original parent cell
•The daughter cells contain the exact same genetic info (the
same # of chromosomes)
Function of Mitosis
• growth (how we grow or the pumpkin on page 461)
•repair (regenerate damaged tissues -a cut on your finger)
•some simpler organisms can regenerate entire body parts (starfish arm or lobster claw)
•maintenance of the body (replace cells that die or don’t work properly - red blood cells)
mitosis and cytokinesis occur in our body cells (also known as somatic cells)
Objective #2 maintaining the Chromosome Number
•Why do your cells need to copy their DNA before they can create a copy of
themselves.
-- so that each new skin cell will have a full set of genetic info (DNA)
•the function of mitosis is to maintain the same number of chromosomes from the original parent cell to the two new daughter cells
•What would happen if the parent cell underwent mitosis before the genetic info was
copied?
--the two new daughter cells would only have half the genetic info needed
•eg. all human somatic cells have 46 chromosomes
•DNA is copied during interphase, before mitosis occurs
•If mitosis occurred first, each daughter cell would have 23 chromosomes instead ofthe 46 that it needs.
Objective 5 file below - radiation and chemotherapy (handout given in class)
• growth (how we grow or the pumpkin on page 461)
•repair (regenerate damaged tissues -a cut on your finger)
•some simpler organisms can regenerate entire body parts (starfish arm or lobster claw)
•maintenance of the body (replace cells that die or don’t work properly - red blood cells)
mitosis and cytokinesis occur in our body cells (also known as somatic cells)
Objective #2 maintaining the Chromosome Number
•Why do your cells need to copy their DNA before they can create a copy of
themselves.
-- so that each new skin cell will have a full set of genetic info (DNA)
•the function of mitosis is to maintain the same number of chromosomes from the original parent cell to the two new daughter cells
•What would happen if the parent cell underwent mitosis before the genetic info was
copied?
--the two new daughter cells would only have half the genetic info needed
•eg. all human somatic cells have 46 chromosomes
•DNA is copied during interphase, before mitosis occurs
•If mitosis occurred first, each daughter cell would have 23 chromosomes instead ofthe 46 that it needs.
Objective 5 file below - radiation and chemotherapy (handout given in class)
radiation_and_chemotherapy.docx | |
File Size: | 14 kb |
File Type: | docx |
Objective 6-7 meiosis file below
meiosis_and_sexual_reproduction_2013.docx | |
File Size: | 15 kb |
File Type: | docx |
Objective 8 - Crossing over - p. 471 and pic p. 473•when non-sister chromatids exchange sections of a chromosome.
•this allows greater variation in the sex cells (recombination of genes)
•after crossing over, the chromosome will contain some genetic information from the mother, and some from the father
•occurs in prophase I of meiosis
•this allows greater variation in the sex cells (recombination of genes)
•after crossing over, the chromosome will contain some genetic information from the mother, and some from the father
•occurs in prophase I of meiosis
Objective 9 file below - spermatogenesis and oogenesis (handout given in
class)
spermatogenesis_and_oogenesis.docx | |
File Size: | 14 kb |
File Type: | docx |
Objective 10
•After meiosis I the cytoplasm has divided unevenly
•most of the cytoplasm goes to the primary oocyte
•the other cell is the polar body - it is not viable
•both of these cells undergo meiosis II
•primary oocyte produces an ovum and another polar body
•the polar body divides to produce two polar bodies
•In total there is one egg (ovum) and 3 polar bodies, which disintegrate
•The purpose is to ensure the ovum has enough nutrients after it has been fertilized but before it attaches to the uterus
•After meiosis I the cytoplasm has divided unevenly
•most of the cytoplasm goes to the primary oocyte
•the other cell is the polar body - it is not viable
•both of these cells undergo meiosis II
•primary oocyte produces an ovum and another polar body
•the polar body divides to produce two polar bodies
•In total there is one egg (ovum) and 3 polar bodies, which disintegrate
•The purpose is to ensure the ovum has enough nutrients after it has been fertilized but before it attaches to the uterus
Objective 11 - Comparing the structure of sperm and eggs p. 478
Eggs
•100 microns in diameter•
•Only live one day if unfertilized; implants after in endometrium
•Mitochondria – 140,000
•300,000-400,000 oogonia – 1 egg produced each month
•Non-motile
•No acrosome, but has a special coating – becomes impenetrable once fertilized
Sperm
•50 microns long (tail is 40 of those)
•Mitochondria – process fat before ejaculation; fructose after
•Mitochondria – 50-100, which supplies ATP
•300-500 million sperm
•Sperm have flagella to swim
•Sperm head has a cap – acrosome (contains enzymes)
Objective 12 - handout given in class (and refer to p. 479 for background info on stem cell research)
Objective 13-14 - handout given in class (attached below)
Eggs
•100 microns in diameter•
•Only live one day if unfertilized; implants after in endometrium
•Mitochondria – 140,000
•300,000-400,000 oogonia – 1 egg produced each month
•Non-motile
•No acrosome, but has a special coating – becomes impenetrable once fertilized
Sperm
•50 microns long (tail is 40 of those)
•Mitochondria – process fat before ejaculation; fructose after
•Mitochondria – 50-100, which supplies ATP
•300-500 million sperm
•Sperm have flagella to swim
•Sperm head has a cap – acrosome (contains enzymes)
Objective 12 - handout given in class (and refer to p. 479 for background info on stem cell research)
Objective 13-14 - handout given in class (attached below)
modes_of_reproduction.pdf | |
File Size: | 424 kb |
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