meiosis chapter 8 part ii. octopus sex male reaches under his mantle with tentacle, removes packet...
TRANSCRIPT
![Page 1: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/1.jpg)
MeiosisMeiosis
Chapter 8Chapter 8
Part IIPart II
![Page 2: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/2.jpg)
Octopus Sex Octopus Sex
Male reaches under his mantle with Male reaches under his mantle with tentacle, removes packet of sperm, tentacle, removes packet of sperm, and insert it into female’s egg and insert it into female’s egg chamberchamber
Eggs are fertilized and give rise to Eggs are fertilized and give rise to new octopusesnew octopuses
![Page 3: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/3.jpg)
Limpet SexLimpet Sex
Larva can become adult of either sexLarva can become adult of either sex
Depends on whether other limpets are Depends on whether other limpets are
present and what their sex ispresent and what their sex is
Adults can change sex in response to Adults can change sex in response to
new arrivalsnew arrivals
![Page 4: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/4.jpg)
![Page 5: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/5.jpg)
Slipper snailsSlipper snails
HermaphroditicHermaphroditic Stacked on top of each otherStacked on top of each other Young are always maleYoung are always male Can stay male or change to femaleCan stay male or change to female Cannot go back to maleCannot go back to male
![Page 6: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/6.jpg)
![Page 7: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/7.jpg)
Sexual ReproductionSexual Reproduction
Chromosomes are duplicated in Chromosomes are duplicated in germ cellsgerm cells
Germ cells undergo meiosis and Germ cells undergo meiosis and cytoplasmic divisioncytoplasmic division
Cellular descendents of germ cells Cellular descendents of germ cells become gametesbecome gametes
Gametes meet at fertilization Gametes meet at fertilization
![Page 8: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/8.jpg)
Meiosis
![Page 9: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/9.jpg)
Asexual Reproduction Asexual Reproduction
Single parent produces offspringSingle parent produces offspring
All offspring are genetically identical All offspring are genetically identical to one another and to parentto one another and to parent
![Page 10: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/10.jpg)
Sexual ReproductionSexual Reproduction
InvolvesInvolves
MeiosisMeiosis
Gamete productionGamete production
FertilizationFertilization Produces genetic variation among Produces genetic variation among
offspringoffspring
![Page 11: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/11.jpg)
Homologous Homologous Chromosomes Carry Chromosomes Carry
Different AllelesDifferent Alleles Cell has two of each chromosome Cell has two of each chromosome
One chromosome in each pair from One chromosome in each pair from
mother, other from fathermother, other from father
Paternal and maternal chromosomes Paternal and maternal chromosomes
carry different allelescarry different alleles
![Page 12: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/12.jpg)
Alleles- Different forms of a Alleles- Different forms of a genegene
![Page 13: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/13.jpg)
What is a gene?What is a gene?
Chemical factors that determine Chemical factors that determine traitstraits
![Page 14: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/14.jpg)
Sexual Reproduction Sexual Reproduction Shuffles AllelesShuffles Alleles
Through sexual reproduction, Through sexual reproduction, offspring inherit new combinations offspring inherit new combinations of alleles, which leads to variations of alleles, which leads to variations in traitsin traits
This variation in traits is the basis This variation in traits is the basis for evolutionary changefor evolutionary change
![Page 15: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/15.jpg)
Gamete FormationGamete Formation
Gametes are sex cells (sperm, eggs)Gametes are sex cells (sperm, eggs) Arise from germ cellsArise from germ cells
testes
ovaries
anther ovary
![Page 16: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/16.jpg)
![Page 17: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/17.jpg)
![Page 18: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/18.jpg)
Chromosome NumberChromosome Number
Sum total of chromosomes in a cellSum total of chromosomes in a cell
Germ cells are diploid (2Germ cells are diploid (2nn))
Gametes are haploid (Gametes are haploid (nn))
Meiosis halves chromosome numberMeiosis halves chromosome number
![Page 19: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/19.jpg)
Meiosis: Two DivisionsMeiosis: Two Divisions
Two consecutive nuclear divisions Two consecutive nuclear divisions Meiosis IMeiosis I
Meiosis IIMeiosis II
DNA is NOT duplicated between DNA is NOT duplicated between
divisionsdivisions
Four haploid nuclei are formedFour haploid nuclei are formed
![Page 20: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/20.jpg)
Meiosis IMeiosis I
Each homologue in the cell pairs with its partner,
then the partners separate
![Page 21: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/21.jpg)
Meiosis IIMeiosis II
The two sister chromatids of each The two sister chromatids of each duplicated chromosome are duplicated chromosome are separated from each otherseparated from each other
one chromosome (duplicated)
two chromosomes (unduplicated)
![Page 22: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/22.jpg)
Stages of MeiosisStages of Meiosis
Meiosis IMeiosis I
Prophase IProphase I Metaphase IMetaphase I Anaphase IAnaphase I Telophase ITelophase I
Meiosis IIMeiosis II
Prophase IIProphase II Metaphase IIMetaphase II Anaphase IIAnaphase II Telophase IITelophase II
![Page 23: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/23.jpg)
Meiosis I - StagesMeiosis I - Stages
Prophase I Metaphase I Anaphase I Telophase I
![Page 24: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/24.jpg)
46
92 9292
![Page 25: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/25.jpg)
92
46x2 46x2 46x2 23x4
![Page 26: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/26.jpg)
![Page 27: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/27.jpg)
![Page 28: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/28.jpg)
Section 11-4
Figure 11-15 Meiosis
Meiosis I
![Page 29: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/29.jpg)
Meiosis II
Meiosis I results in two haploid (N) daughter cells, each with half the number of chromosomes as the original.
Prophase II Metaphase II Anaphase II Telophase IIThe chromosomes line up in a similar way to the metaphase stage of mitosis.
The sister chromatids separate and move toward opposite ends of the cell.
Meiosis II results in four haploid (N) daughter cells.
Section 11-4
Figure 11-17 Meiosis II
![Page 30: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/30.jpg)
Prophase IProphase I
Each duplicated, condensed Each duplicated, condensed chromosome pairs with its homologuechromosome pairs with its homologue
Homologues swap segmentsHomologues swap segments
Each chromosome becomes attached Each chromosome becomes attached to microtubules of newly forming to microtubules of newly forming spindlespindle
![Page 31: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/31.jpg)
Crossing-Over
![Page 32: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/32.jpg)
Crossing-Over
![Page 33: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/33.jpg)
Crossing-Over
![Page 34: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/34.jpg)
Crossing OverCrossing Over
•Each chromosome
becomes zippered to its
homologue
•All four chromatids are
closely aligned
•Non-sister chromosomes
exchange segments
![Page 35: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/35.jpg)
Effect of Crossing OverEffect of Crossing Over
After crossing over, each After crossing over, each
chromosome contains both maternal chromosome contains both maternal
and parental segmentsand parental segments
Creates new allele combinations in Creates new allele combinations in
offspringoffspring
![Page 36: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/36.jpg)
Metaphase IMetaphase I
Chromosomes are pushed and pulled Chromosomes are pushed and pulled into the middle of cellinto the middle of cell
Sister chromatids of one homologue Sister chromatids of one homologue orient toward one pole, and those of orient toward one pole, and those of other homologue toward opposite pole other homologue toward opposite pole
The spindle is now fully formedThe spindle is now fully formed
![Page 37: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/37.jpg)
Anaphase IAnaphase I
Homologous chromosomes Homologous chromosomes
segregate from each other segregate from each other
The sister chromatids of each The sister chromatids of each
chromosome remain attachedchromosome remain attached
![Page 38: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/38.jpg)
Telophase ITelophase I
The chromosomes arrive at opposite The chromosomes arrive at opposite
polespoles
The cytoplasm dividesThe cytoplasm divides
There are now two haploid cellsThere are now two haploid cells
This completes Meiosis IThis completes Meiosis I
![Page 39: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/39.jpg)
Meiosis II - StagesMeiosis II - Stages
Prophase II Metaphase II Anaphase II Telophase II
![Page 40: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/40.jpg)
Prophase IIProphase II
Microtubules attach to the Microtubules attach to the kinetochores of the duplicated kinetochores of the duplicated chromosomeschromosomes
Motor proteins drive the movement Motor proteins drive the movement of chromosomes toward the of chromosomes toward the spindle’s equatorspindle’s equator
![Page 41: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/41.jpg)
Metaphase IIMetaphase II
All of the duplicated chromosomes All of the duplicated chromosomes are lined up at the spindle are lined up at the spindle equator, midway between the equator, midway between the polespoles
![Page 42: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/42.jpg)
Anaphase IIAnaphase II
Sister chromatids separate to Sister chromatids separate to become independent chromosomesbecome independent chromosomes
Motor proteins interact with Motor proteins interact with microtubules to move the separated microtubules to move the separated chromosomes to opposite poleschromosomes to opposite poles
![Page 43: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/43.jpg)
Telophase IITelophase II
The chromosomes arrive at opposite The chromosomes arrive at opposite ends of the cellends of the cell
A nuclear envelope forms around A nuclear envelope forms around each set of chromosomeseach set of chromosomes
The cytoplasm dividesThe cytoplasm divides There are now four haploid cells There are now four haploid cells
![Page 44: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/44.jpg)
Random Alignment Random Alignment
During transition between prophase During transition between prophase I and metaphase I, microtubules I and metaphase I, microtubules from spindle poles attach to from spindle poles attach to kinetochores of chromosomes kinetochores of chromosomes
Initial contacts between Initial contacts between microtubules and chromosomes are microtubules and chromosomes are randomrandom
![Page 45: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/45.jpg)
Random AlignmentRandom Alignment
Either the maternal or paternal Either the maternal or paternal member of a homologous pair can member of a homologous pair can end up at either poleend up at either pole
The chromosomes in a gamete are a The chromosomes in a gamete are a mix of chromosomes from the two mix of chromosomes from the two parents parents
![Page 46: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/46.jpg)
Possible Chromosome Possible Chromosome CombinationsCombinations
As a result of random alignment, the As a result of random alignment, the number of possible combinations of number of possible combinations of
chromosomes in a gamete is: chromosomes in a gamete is:
22nn
((nn is number of chromosome types) is number of chromosome types)
![Page 47: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/47.jpg)
Possible Possible ChromosomChromosom
eeCombinatioCombinatio
ns ns
or
or
or
1 2 3
![Page 48: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/48.jpg)
Plant Life CyclePlant Life Cycle
multicelled sporophyte
multicelled gametophytes
zygote
gametes spores
meiosisfertilization
mitosis
mitosis
Diploid
Haploid
![Page 49: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/49.jpg)
Animal Life CycleAnimal Life Cycle
multicelled body
gametes
zygote
meiosisfertilization
mitosis
Diploid
Haploid
![Page 50: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/50.jpg)
SpermatogenesisSpermatogenesis
GrowthMitosis I,
Cytoplasmic divisionMeiosis II,
Cytoplasmic division
spermatids (haploid)
secondary spermatocytes
(haploid)
primary spermatocyte
(diploid)
spermato-gonium
(diploid male reproductive
cell)
![Page 51: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/51.jpg)
OogenesisOogenesis
Growth Mitosis I,Cytoplasmic division
Meiosis II,Cytoplasmic division
ovum (haploid)
primary oocyte (diploid)
oogonium (diploid
reproductive cell) secondary
oocyte haploid)
first polar body
haploid)
three polar bodies
haploid)
![Page 52: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/52.jpg)
FertilizationFertilization
Male and female gametes unite and Male and female gametes unite and
nuclei fusenuclei fuse
Fusion of two haploid nuclei produces Fusion of two haploid nuclei produces
diploid nucleus in the zygotediploid nucleus in the zygote
Which two gametes unite is randomWhich two gametes unite is random Adds to variation among offspringAdds to variation among offspring
![Page 53: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/53.jpg)
Factors Contributing to Factors Contributing to Variation Among Variation Among
OffspringOffspring Crossing over during prophase ICrossing over during prophase I
Random alignment of Random alignment of
chromosomes at metaphase Ichromosomes at metaphase I
Random combination of gametes Random combination of gametes
at fertilizationat fertilization
![Page 54: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/54.jpg)
MitosisMitosis FunctionsFunctions
Asexual Asexual reproductionreproduction
Growth, repair Growth, repair Occurs in somatic Occurs in somatic
cellscells Produces clonesProduces clones
Mitosis & Meiosis Mitosis & Meiosis ComparedCompared
MeiosisMeiosis Function Function
Sexual reproductionSexual reproduction
Occurs in germ Occurs in germ cellscells
Produces variable Produces variable offspringoffspring
![Page 55: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/55.jpg)
Prophase vs. Prophase I Prophase vs. Prophase I
Prophase (Mitosis)Prophase (Mitosis) Homologous pairs do not interact with Homologous pairs do not interact with
each othereach other
Prophase I (Meiosis) Prophase I (Meiosis) Homologous pairs become zippered Homologous pairs become zippered
together and crossing over occurstogether and crossing over occurs
![Page 56: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/56.jpg)
Anaphase, Anaphase I, Anaphase, Anaphase I, and Anaphase IIand Anaphase II
Anaphase I (Meiosis)Anaphase I (Meiosis)
Homologous chromosomes are separated Homologous chromosomes are separated
from each otherfrom each other
Anaphase/Anaphase II Anaphase/Anaphase II
(Mitosis/Meiosis)(Mitosis/Meiosis)
Sister chromatids of a chromosome are Sister chromatids of a chromosome are
separated from each otherseparated from each other
![Page 57: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/57.jpg)
Results of Mitosis and Results of Mitosis and MeiosisMeiosis
MitosisMitosis Two diploid cells producedTwo diploid cells produced
Each identical to parentEach identical to parent
MeiosisMeiosis Four haploid cells producedFour haploid cells produced
Differ from parent and one anotherDiffer from parent and one another
![Page 58: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/58.jpg)
Pre-Natal Tests - help to determine if an at risk baby is healthy
![Page 59: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/59.jpg)
Sex chromosomes
Human Karyotype
![Page 60: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/60.jpg)
Sex Chromosomes
![Page 61: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/61.jpg)
Down Syndrome (trisomy 21),
47,XY,+21.
47: the total number of chromosomes (46 is normal).
XY: the sex chromosomes (male).
+21: designates the extra chromosome as a 21.
![Page 62: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/62.jpg)
Klinefelter’s Syndrome
47, XXY
![Page 63: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/63.jpg)
Turner’s SyndromeTurner’s Syndrome
Only one complete XOnly one complete X The second could also be incompleteThe second could also be incomplete In almost all cases, unable to repro. In almost all cases, unable to repro.
Or menstruate Or menstruate
![Page 64: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/64.jpg)
HermaphroditeHermaphrodite
XX/XY or XOXX/XY or XO 350-400 Known cases350-400 Known cases
![Page 65: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/65.jpg)
Gene Therapy - an absent or faulty gene is replaced by a working gene
Has not been very successful
![Page 66: Meiosis Chapter 8 Part II. Octopus Sex Male reaches under his mantle with tentacle, removes packet of sperm, and insert it into females egg chamber Male](https://reader036.vdocuments.net/reader036/viewer/2022062511/5514f504550346a80c8b4ec3/html5/thumbnails/66.jpg)