cell reproduction page #1 warm up where are your genes located?
TRANSCRIPT
Cell ReproductionPage #1
Warm Up
Where are your genes located?
http://people.na.infn.it/~nicodem/research/cell_genes.jpg
•DURING MOST OF THE CELL’S LIFE, DNA FORMS A TANGLED MASS CALLED CHROMATIN.
•CHROMATIN LOOKS LIKE A PLATE OF SPAGHETTI.
•RIGHT BEFORE A CELL DIVIDES, THE CHROMATIN FORMS INTO CHROMOSOMES
(X-SHAPED).
MOST OF THE TIME ONCE IN A WHILE
CHROMATIN CHROMOSOMES
Cell Division
• Chromosomes = Tightly coiled, rod-shaped DNA• Chromosomes are made of chromatin• Human body produces 2 trillion cells per day & 25
million per second• Cells are formed by cell division of older cells
1. When a cell divides, DNA is first copied & then distributed
2. Each cell ends up with a complete set of DNA
Chromosome Number
• Each human somatic cell has 2 copies of 23 different chromosomes – Total 46– Somatic = any cell that is NOT a sex cell– (also called body cells or autosomes)
Sets of Chromosomes
• Each pair is made up of 2 homologous chromosomes– Homologous chromosomes = chromosomes that are similar
in size, shape, & genetic content
– Each homologue comes from one of the parents• One from mom
• One from dad
Cells Can Be Diploid or Haploid
• Diploid = a cell that contains 2 sets of chromosomes (2n)
• Haploid (monoploid) = a cell that contains only 1 set of chromosomes (1n or n)
Chromosomes Determine Your Gender
• Humans have 23 pairs of chromosomes
• 22 pairs are autosomes (chromosomes NOT directly involved in determining sex)
• 1 pair are sex chromosomes (contain genes that WILL determine the sex)– X & Y chromosomes
X & Y Chromosomes
• Male = XY• Female = XX• Male (dad) can donate an X or a Y to
offspring• Female (mom) can ONLY donate an X
So-Which parent determines the sex of the baby?
MALEXY
Gametes
• Gametes are reproductive cells– Males = sperm (n = 23)– Female = egg (n = 23)
• Combine in fertilization to make a: – Zygote (2n = 46)
Haploid VS Diploid
Page #2
““UnderstandingUnderstandingthe concepts ofthe concepts of
Haploid and Haploid and Diploid”Diploid”
Haploid and DiploidHaploid and Diploid
Introducing VocabularyIntroducing Vocabulary
Diploid= DIH – Diploid= DIH – ploydployd
Haploid= HA – Haploid= HA – ploydployd
Let’s take a look at the terms first….Let’s take a look at the terms first….
Diploid= Diploid= Di Di Ploid Ploid““DiDi” means “” means “twotwo””
Haploid and DiploidHaploid and Diploid
Let’s take a look at the terms first….Let’s take a look at the terms first….
Haploid= Haploid= HaHa Ploid Ploidthink “think “HAHAlf”lf”
haploidhaploid is is half half of diploid.of diploid.
Haploid and DiploidHaploid and Diploid
ReviewReview
““DiploidDiploid” means” means
Haploid and DiploidHaploid and Diploid
Half Two
ReviewReview
““HaploidHaploid” means” means
Haploid and DiploidHaploid and Diploid
Half Two
GOOD JOB !!!GOOD JOB !!!
You’re on the way !!!You’re on the way !!!
Introducing VocabularyIntroducing Vocabulary
Gamete= GA - Gamete= GA - meatmeat
Somatic= So-MA-Somatic= So-MA-tiktik
A A “Gamete”“Gamete” is a is a generic term for a generic term for a
“sex cell”.“sex cell”. An example would be An example would be
a a spermsperm or an or an eggegg..
Haploid and DiploidHaploid and Diploid
Gametes areGametes are HaploidHaploid in in
chromosome chromosome number.number.
Haploid and DiploidHaploid and Diploid
The The numbernumber of of chromosomes that a chromosomes that a
gamete gamete would contain would contain would be would be described described
as______as______
Haploid and DiploidHaploid and Diploid
Haploid Diploid
““Somatic cellsSomatic cells” ” refers to refers to every every otherother cell cell in the in the
body body exceptexcept gametes.gametes.
Haploid and DiploidHaploid and Diploid
ReviewReview
SpermSperm or or EggEgg = = GametesGametesAll All Other Other cells = cells = SomaticSomatic
CellsCells
Haploid and DiploidHaploid and Diploid
Gamete or Somatic Cell ?Gamete or Somatic Cell ?
A Liver CellA Liver Cell
Haploid and DiploidHaploid and Diploid
GameteSomatic
Cell
Gamete or Somatic Cell ?Gamete or Somatic Cell ?
A Sperm CellA Sperm Cell
Haploid and DiploidHaploid and Diploid
GameteSomatic
Cell
Gamete or Somatic Cell ?Gamete or Somatic Cell ?
A Brain CellA Brain Cell
Haploid and DiploidHaploid and Diploid
GameteSomatic
Cell
Gamete or Somatic Cell ?Gamete or Somatic Cell ?
A Lung CellA Lung Cell
Haploid and DiploidHaploid and Diploid
GameteSomatic
Cell
Gamete or Somatic Cell ?Gamete or Somatic Cell ?
An EggAn Egg
Haploid and DiploidHaploid and Diploid
GameteSomatic
Cell
Gamete or Somatic Cell ?Gamete or Somatic Cell ?
A Skin CellA Skin Cell
Haploid and DiploidHaploid and Diploid
GameteSomatic
Cell
Keep Going !!!Keep Going !!!
HAlf way There !!!HAlf way There !!!
Somatic Cells Somatic Cells areare DiploidDiploid in in chromosome chromosome
number.number.
Haploid and DiploidHaploid and Diploid
The The numbernumber of of chromosomes that a chromosomes that a somatic cell somatic cell would would contain would be contain would be described as______described as______
Haploid and DiploidHaploid and Diploid
Haploid Diploid
ReviewReview
Gametes =Gametes = haploid haploidSomatic Cells = Somatic Cells =
diploiddiploid
Haploid and DiploidHaploid and Diploid
Mathematically SpeakingMathematically Speaking
if if haploid=nhaploid=n,,then then diploid=2ndiploid=2n
Haploid and DiploidHaploid and Diploid
Mathematically Mathematically SpeakingSpeaking
or… or… haploid is haploid is ½½ of of diploiddiploid
or… or… diploid is diploid is 2x2x haploid haploid
Haploid and DiploidHaploid and Diploid
ReviewReview
SpermSperm or or EggEgg = = GametesGametes==HaploidHaploid==nnAll All Other Other Cells = Cells = SomaticSomatic CellsCells==DiploidDiploid==2n2n
Haploid and DiploidHaploid and Diploid
Humans have Humans have 4646 chromosomes in their chromosomes in their somatic cellssomatic cells. These . These
cells are cells are ____________
Haploid and DiploidHaploid and Diploid
Haploid Diploid
Humans have Humans have 2323 chromosomes in their chromosomes in their gametesgametes. These cells . These cells
are are ____________
Haploid and DiploidHaploid and Diploid
Haploid Diploid
IfIf humans humans diploiddiploid number = number = 4646, what , what
is the is the haploidhaploid number?number?
Haploid and DiploidHaploid and Diploid
23 92
IfIf humans humans haploidhaploid number = number = 2323, what , what
is the is the diploiddiploid number?number?
Haploid and DiploidHaploid and Diploid
46 92
IfIf chimps chimps diploiddiploid number = number = 4848, what , what
is the is the haploidhaploid number?number?
Haploid and DiploidHaploid and Diploid
24 96
IfIf chimps chimps haploidhaploid number = number = 2424, what , what
is the is the diploiddiploid number?number?
Haploid and DiploidHaploid and Diploid
48 96
Review AgainReview Again
Sperm or Egg = Gametes=Haploid= Sperm or Egg = Gametes=Haploid= nnAll Other Cells = Somatic Cells=Diploid= All Other Cells = Somatic Cells=Diploid= 2n2n
Haploid and DiploidHaploid and Diploid
IfIf humans humans diploiddiploid number = number = 4646,, How many How many
chromosomes in achromosomes in a liverliver cell ? cell ?
Haploid and DiploidHaploid and Diploid
23 46
IfIf humans humans diploiddiploid number = number = 4646,, How many How many
chromosomes in a chromosomes in a spermsperm cell ? cell ?
Haploid and DiploidHaploid and Diploid
23 46
IfIf humans humans diploiddiploid number = number = 4646,, How many How many
chromosomes in achromosomes in a brainbrain cell ? cell ?
Haploid and DiploidHaploid and Diploid
23 46
IfIf humans humans diploiddiploid number = number = 4646,, How many How many
chromosomes in achromosomes in a lunglung cell ? cell ?
Haploid and DiploidHaploid and Diploid
23 46
IfIf humans humans diploiddiploid number = number = 4646,, How many How many
chromosomes in an chromosomes in an eggegg cell ? cell ?
Haploid and DiploidHaploid and Diploid
23 46
IfIf humans humans diploiddiploid number = number = 4646,, How many How many
chromosomes in achromosomes in a skinskin cell ? cell ?
Haploid and DiploidHaploid and Diploid
23 46
Up so far !!!Up so far !!!
ALMOST THERE !!!ALMOST THERE !!!
Review Last RoundReview Last Round
Sperm or Egg = Gametes=Haploid= Sperm or Egg = Gametes=Haploid= nnAll Other Cells = Somatic Cells=Diploid= All Other Cells = Somatic Cells=Diploid= 2n2n
Haploid and DiploidHaploid and Diploid
If If chimp’schimp’s haploid haploid number = number = 2424,, How many How many
chromosomes in achromosomes in achimp’schimp’s liverliver cell ? cell ?
Haploid and DiploidHaploid and Diploid
24 48
If If chimp’schimp’s haploid haploid number = number = 2424,, How many How many
chromosomes in achromosomes in achimp’schimp’s eggegg cell ? cell ?
Haploid and DiploidHaploid and Diploid
24 48
If If Horse’sHorse’s diploid diploid number = number = 6464,, How many How many
chromosomes in achromosomes in aHorse’sHorse’s liverliver cell ? cell ?
Haploid and DiploidHaploid and Diploid
32 64
If If Alligators’sAlligators’s diploid diploid number = number =
3232,, How many How many chromosomes in achromosomes in aAlligators’sAlligators’s liverliver
cell ?cell ?
Haploid and DiploidHaploid and Diploid
32 64
If If Dog’sDog’s diploid diploid number = number = 7878,, How many How many
chromosomes in achromosomes in aDog’sDog’s spermsperm cell ? cell ?
Haploid and DiploidHaploid and Diploid
39 78
http://www.goldiesroom.org/http://www.goldiesroom.org/Shockwave_Pages/REG-15-Shockwave_Pages/REG-15-haplodvdiploid.htmhaplodvdiploid.htm
Mitosis Animation Mitosis Animation
http://www.goldiesroom.org/http://www.goldiesroom.org/Shockwave_Pages/REG-14-tnm--Shockwave_Pages/REG-14-tnm--celldivision.htmcelldivision.htm
Page #3 Karyotype
• Karyotype = a photo of the chromosomes in a dividing cell that shows the chromosomes arranged by size.
Karyotype cont’d
• Each of an individual’s 46 chromosomes has thousands of genes so the presence of all chromosomes is essential for normal functioning– Humans who are missing a chromosome don’t
survive– Humans with more than two copies of a
chromosome, called trisomy, may survive but will not develop properly.
What is wrong?
The Cell Cycle
• Repeating sequence of cell growth and division during an organism’s life
• 90% of cell life is spent in INTERPHASE
• Then it may go into MITOSIS & CYTOKINESIS
INTERPHASE(divided into mini-phases)
• G1(first growth) phase = Cell grows rapidly
• S (synthesis) phase = DNA copied
• G2 (2nd growth) phase = Nucleus prepares to divide
http://publications.nigms.nih.gov/insidethecell/ch4_interphase_big.html
AFTER INTERPHASE
• Mitosis
• Cytokinesis
• http://www.cellsalive.com/cell_cycle.htm
Mitosis and Meiosis
WARM UP
Females are X___Males are X___
Having 3 copies of a chromosome is called a ______________
Mitosis and Meiosis
• Mitosis:-division of somatic (body) cells- results in two daughter cells that are identical
• Meiosis-division of gametes (sex cells)
Mitosis
• Interphase
• Prophase
• Metaphase
• Anaphase
• Telophase
The Cell Cycle is Carefully Controlled
• Key check points which feedback signals from the cell will delay the next step
• Controlled by proteins!
1. Cell Growth CHECKPOINT (G1) – Start – Nerve/muscle cells stop here
2. DNA Synthesis CHECKPOINT (G2) – Enzymes
3. Mitosis CHECKPOINT – Back to G1 phase
Page #4When Control is Lost -- Cancer
• Cancer = Cell growth is uncontrolled - does not respond to control mechanisms.
• Causes: Mutations that cause over-production of growth molecules – (accelerator) or by in-activating proteins that slow or stop the cell cycle (brakes)
• Tobacco and UV radiation linked to increased cancer risk.
Change in Chromosome Number
• Trisomy = humans with more than 2 copies of chromosomes – improper development
• Karyotype = a photo of the chromosomes in a dividing cell.
• Disjunction = when egg/sperm cells form – each chromosome and homologue separate – sometimes one or more chromosomes fail to separate - unequal distribution.
• Down Syndrome - 3 copies of chromosome 21- NONDISJUNCTION
Change in Chromosome Structure
• Mutation – A change in an organism’s chromosomal structure.
• Deletion = piece of chromosome breaks off completely – lacks of a set of genes – fatal
• Duplication = chromosome fragment attaches to its homologous chromosome –two copies of a gene set
• Inversion = chromosome piece reattaches to original chromosome, but in reverse orientation.
• Translocation = chromosome piece reattaches to a nonhomologous chromosome.
Interphase
• Interesting things happen!1. Cell preparing to divide2. Genetic material doubles
Prophase
• Chromosome pair up!1. Chromosomes thicken and shorten
-become visible-2 chromatids joined by a centromere
2. Centrioles move to the opposite sides of the nucleus
3. Nucleolus disappears
Metaphase
• Chromosomes meet in the middle!
1. Chromosomes arrange at equator of cell
2. Become attached to spindle fibres by centromeres
3. Homologous chromosomes do not associate
Anaphase
• Chromosomes get pulled apart1. Spindle fibres contract pulling
chromatids to the opposite poles of the cell
Telophase
• Now there are almost two!1. Chromosomes uncoil2. Spindle fibres disintegrate3. Centrioles replicate
Cytokinesis
• Cell splits
http://www.cellsalive.com/mitosis.htm
Metaphase
Telophase
Prophase
Anaphase
http://www.youtube.com/watch?v=HV5kPiDYC3M
Cell Reproduction Cell Reproduction Page #5Page #5
Warm UpWarm Up
List the stages of mitosis in orderList the stages of mitosis in order
IPMATIPMAT
MeiosisMeiosis
Meiosis = Meiosis = Cell divisionCell division that produces only that produces only haploid cells (half the number of haploid cells (half the number of chromosomes)chromosomes)Sex cells or gametesSex cells or gametesSpermatogenesisSpermatogenesisOogenesisOogenesis
Meiosis Occurs in Two StagesMeiosis Occurs in Two Stages
Meiosis IMeiosis I
Meiosis IIMeiosis II
Follows the same order as MITOSIS, but it Follows the same order as MITOSIS, but it does it does it TWICETWICE
Meiosis IMeiosis I
Homologous chromosomes Homologous chromosomes are separated into are separated into separate separate cells.cells.
Interphase IInterphase I
Cell doubles its DNA and Cell doubles its DNA and then doubles it againthen doubles it again
http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/meiosis1.html
Prophase IProphase I
Chromosomes formChromosomes formCrossing over takes placeCrossing over takes place
http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/meiosis3.html
Crossing OverCrossing Over
Exchanging corresponding segments of Exchanging corresponding segments of DNADNA
Important because it gives a new Important because it gives a new combination of combination of genes.genes.
Crossing OverCrossing Overhttp://waynesword.palomar.edu/images/cross3.jpghttp://waynesword.palomar.edu/images/cross3.jpg
Metaphase IMetaphase I
Chromosomes line up Chromosomes line up in the in the middlemiddle..
http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/meiosis4.html
Anaphase IAnaphase I
Chromosomes Chromosomes separateseparate
http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/meiosis5.html
Telophase ITelophase I
Cell begins to divide Cell begins to divide & 2 new cells form & 2 new cells form (cytokinesis)(cytokinesis)
Each cell has Each cell has chromosomeschromosomes
http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/Meiosis6.html
Meiosis IIMeiosis II
ChromatidsChromatids of each chromosome are of each chromosome are separated into separate cellsseparated into separate cells
http://botit.botany.wisc.edu/images/130/Meiosis/Lilium_microsporogenesis/Meiosis_II.html
Prophase IIProphase II
Chromosomes form in Chromosomes form in both cellsboth cells
http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/Meiosis7.html
Metaphase IIMetaphase II
Chromosomes line up Chromosomes line up along middle of cellalong middle of cell
http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/Meiosis8.html
Anaphase IIAnaphase II
Chromosomes Chromosomes separate and are separate and are pulled apart into pulled apart into chromatidschromatids
http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/Meiosis9.html
http://www.scq.ubc.ca/filter/wp-content/uploads/2007/10/sister-chromatid.gif
Telophase IITelophase II
Chromatids gather at Chromatids gather at ends of cellsends of cells
Cytokinesis occurs – Cytokinesis occurs – (cell splits apart)(cell splits apart)
http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/Meiosis10.html
End Result of Meiosis & End Result of Meiosis & CytokinesisCytokinesis
44 new cells each with new cells each with half as much half as much geneticgenetic info as the parentinfo as the parent
http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/Meiosis10.html
http://www.cellsalive.com/meiosis.htm
SpermatogenesisSpermatogenesis
http://www.soc.ucsb.edu/sexinfo/images/12-06-spermatogenesis.gif
OogenesisOogenesis
http://img.sparknotes.com/content/testprep/bookimgs/sat2/biology/0003/oogenesis.gif