AS.020.151 Chapter Notes - Chapter 7: Cell Division, Dna Replication, Sexual Reproduction
12 Jun 2018
School
Department
Course
Main%Concepts:
-why%cells%need%to%divide
-cell%division%in%prokaryotes%vs%eukaryotes
-prokaryotic%cell%division:%binary%fission
-all%cell%division:%signal,%replication,%segregation,%cytokinesis
-Cell%Cycle%(diagram):%G1,%S,%G2,%M
-DNA%replication%in%prokaryotes%and%eukaryotes
-homologous%chromosomes
-eukaryotic%chromosome%structure
-cytokinesis%in%pro%vs%euk
-mitosis%and%meiosis
-goal%of%mitosis:%two%identical%cells%(PPMAT)
-goal%of%meiosis:%produce%gametes%(half%DNA%of%original%cells)
-asexual%vs.%sexual%reproduction
-meiosis%I%and%meiosis%II
Different%Modes%of%Cell%Reproduction
Cell%division:%parent%cell%duplicates%genetic%material%and%divides%into%two%similar%cells
-important%in%growth%and%repair%of%tissues%and%reproduction
Two%basic%strategies:%Asexual%and%Sexual%reproduction
Asexual%reproduction:%offspring%are%clones%of%the%parent%organisms,%genetically%identical%(ignoring%mutation)
Sexual%reproduction:%fusion%of%two%gametes,%offspring%have%considerable%genetic%variation
In%many%diploids,%gametes%form%by%meiosis
Meiosis: cell%division%resulting%in%daughter%cells%with%half%the%DNA%of%the%parent
-DNA%randomly%separated,%so%daughter%cells%vary%from%each%other
-creates%genetic%diversity->natural%selection%and%evolution
Cells%not%specialized%for%reproduction-somatic%cells (two%sets%of%chromosomes,%and%chromosomes%are%in%
homologous%pairs)
Gametes- single%set%of%chromosomes,%one%homolog%from%each%pair,%haploid,%n
-two%haploid%gametes%fuse%to%form%zygote%in%fertilization%(two%sets%of%chromosomes,%diploid,%2n)
-in%most%organisms,%zygote%divides%by%mitosis,%forming%a%new%organism%with%diploid%somatic%cells
Asexual%Reproduction
Prokaryotes-binary%fission
Eukaryotes- mitosis
All%cell%division…
Signal- signal%from%in%or%outside%the%cell%that%initiated%cell%division
DNA%replication
DNA%segregation- cell%must%distribute%replicated%DNA%to%each%of%the%two%new%cells
Cytokinesis-division%of%the%cytoplasm
Binary%Fission%(Prokaryotes):
Cell%division%results%in%the%reproduction%of%an%entire%single-celled%organism
Cell%grows%in%size,%replicates%DNA,%and%then%separates%the%cytoplasm%and%DNA%into%two%new%cells
Eukaryotic%Cell%Cycle
Will%cell%enter%next%phase?
CDK%protein%is%always%present,%but%Cyclin%only%appears%at%certain%times%in%the%cell%cycle.
Cyclin%binds%to%CDK,%exposing%CDK's%active%site,%produces%signal%cascade%to%move%onto%next%phase
Cyclin%made%when%it%shouldn't%be->%cancer->%keep%dividing%and%continuing%through%the%cell%cycle
Mitosis
Goal:%Produce%two%identical%daughter%cells
Steps:
Copying%DNA
Separating%chromosomes
Separating%cell%(reforming%cell%membrane)
Homologous%chromosomes:%two%chromosomes%that%are%similar%but%
not%identical%(different%forms%of%the%same%gene,%one%from%each%
parent)
Sometimes%mitosis%in%M%
and%sometimes%meiosis
Meiosis
Goal: Produce%gametes%(cells%w/%half%DNA%of%original)
Measuring%DNA%in%cell:
Somatic%cells- 2n%and%diploid%(two%copies%of%each%chromosome- one%from%mom%and%one%from%dad)
Gametes- n%and%haploid%(1%copy%of%each%chromosome- randomly%from%mom%or%dad)
Steps:
Two%steps-Meiosis%I%and%Meiosis%II
Meiosis%I1)
Goal:%to%separate%homologous%chromosomes
Meiosis%II2)
Goal:%to%separate%sister%chromatids
Chapter%7:%Cell%Cycle%and%Cell%Division
Monday, October 23, 2017
1:49 PM
Main%Concepts:
-why%cells%need%to%divide
-cell%division%in%prokaryotes%vs%eukaryotes
-prokaryotic%cell%division:%binary%fission
-all%cell%division:%signal,%replication,%segregation,%cytokinesis
-Cell%Cycle%(diagram):%G1,%S,%G2,%M
-DNA%replication%in%prokaryotes%and%eukaryotes
-homologous%chromosomes
-eukaryotic%chromosome%structure
-cytokinesis%in%pro%vs%euk
-mitosis%and%meiosis
-goal%of%mitosis:%two%identical%cells%(PPMAT)
-goal%of%meiosis:%produce%gametes%(half%DNA%of%original%cells)
-asexual%vs.%sexual%reproduction
-meiosis%I%and%meiosis%II
Different%Modes%of%Cell%Reproduction
Cell%division:%parent%cell%duplicates%genetic%material%and%divides%into%two%similar%cells
-important%in%growth%and%repair%of%tissues%and%reproduction
Two%basic%strategies:%Asexual%and%Sexual%reproduction
Asexual%reproduction:%offspring%are%clones%of%the%parent%organisms,%genetically%identical%(ignoring%mutation)
Sexual%reproduction:%fusion%of%two%gametes,%offspring%have%considerable%genetic%variation
In%many%diploids,%gametes%form%by%meiosis
Meiosis: cell%division%resulting%in%daughter%cells%with%half%the%DNA%of%the%parent
-DNA%randomly%separated,%so%daughter%cells%vary%from%each%other
-creates%genetic%diversity->natural%selection%and%evolution
Cells%not%specialized%for%reproduction-somatic%cells (two%sets%of%chromosomes,%and%chromosomes%are%in%
homologous%pairs)
Gametes- single%set%of%chromosomes,%one%homolog%from%each%pair,%haploid,%n
-two%haploid%gametes%fuse%to%form%zygote%in%fertilization%(two%sets%of%chromosomes,%diploid,%2n)
-in%most%organisms,%zygote%divides%by%mitosis,%forming%a%new%organism%with%diploid%somatic%cells
Asexual%Reproduction
Prokaryotes-binary%fission
Eukaryotes- mitosis
All%cell%division…
Signal- signal%from%in%or%outside%the%cell%that%initiated%cell%division
DNA%replication
DNA%segregation- cell%must%distribute%replicated%DNA%to%each%of%the%two%new%cells
Cytokinesis-division%of%the%cytoplasm
Binary%Fission%(Prokaryotes):
Cell%division%results%in%the%reproduction%of%an%entire%single-celled%organism
Cell%grows%in%size,%replicates%DNA,%and%then%separates%the%cytoplasm%and%DNA%into%two%new%cells
Eukaryotic%Cell%Cycle
Will%cell%enter%next%phase?
CDK%protein%is%always%present,%but%Cyclin%only%appears%at%certain%times%in%the%cell%cycle.
Cyclin%binds%to%CDK,%exposing%CDK's%active%site,%produces%signal%cascade%to%move%onto%next%phase
Cyclin%made%when%it%shouldn't%be->%cancer->%keep%dividing%and%continuing%through%the%cell%cycle
Mitosis
Goal:%Produce%two%identical%daughter%cells
Steps:
Copying%DNA
Separating%chromosomes
Separating%cell%(reforming%cell%membrane)
Homologous%chromosomes:%two%chromosomes%that%are%similar%but%
not%identical%(different%forms%of%the%same%gene,%one%from%each%
parent)
Sometimes%mitosis%in%M%
and%sometimes%meiosis
Meiosis
Goal: Produce%gametes%(cells%w/%half%DNA%of%original)
Measuring%DNA%in%cell:
Somatic%cells- 2n%and%diploid%(two%copies%of%each%chromosome- one%from%mom%and%one%from%dad)
Gametes- n%and%haploid%(1%copy%of%each%chromosome- randomly%from%mom%or%dad)
Steps:
Two%steps-Meiosis%I%and%Meiosis%II
Meiosis%I1)
Goal:%to%separate%homologous%chromosomes
Meiosis%II2)
Goal:%to%separate%sister%chromatids
Chapter%7:%Cell%Cycle%and%Cell%Division
Monday, October 23, 2017
1:49 PM
Main%Concepts:
-why%cells%need%to%divide
-cell%division%in%prokaryotes%vs%eukaryotes
-prokaryotic%cell%division:%binary%fission
-all%cell%division:%signal,%replication,%segregation,%cytokinesis
-Cell%Cycle%(diagram):%G1,%S,%G2,%M
-DNA%replication%in%prokaryotes%and%eukaryotes
-homologous%chromosomes
-eukaryotic%chromosome%structure
-cytokinesis%in%pro%vs%euk
-mitosis%and%meiosis
-goal%of%mitosis:%two%identical%cells%(PPMAT)
-goal%of%meiosis:%produce%gametes%(half%DNA%of%original%cells)
-asexual%vs.%sexual%reproduction
-meiosis%I%and%meiosis%II
Different%Modes%of%Cell%Reproduction
Cell%division:%parent%cell%duplicates%genetic%material%and%divides%into%two%similar%cells
-important%in%growth%and%repair%of%tissues%and%reproduction
Two%basic%strategies:%Asexual%and%Sexual%reproduction
Asexual%reproduction:%offspring%are%clones%of%the%parent%organisms,%genetically%identical%(ignoring%mutation)
Sexual%reproduction:%fusion%of%two%gametes,%offspring%have%considerable%genetic%variation
In%many%diploids,%gametes%form%by%meiosis
Meiosis: cell%division%resulting%in%daughter%cells%with%half%the%DNA%of%the%parent
-DNA%randomly%separated,%so%daughter%cells%vary%from%each%other
-creates%genetic%diversity->natural%selection%and%evolution
Cells%not%specialized%for%reproduction-somatic%cells (two%sets%of%chromosomes,%and%chromosomes%are%in%
homologous%pairs)
Gametes- single%set%of%chromosomes,%one%homolog%from%each%pair,%haploid,%n
-two%haploid%gametes%fuse%to%form%zygote%in%fertilization%(two%sets%of%chromosomes,%diploid,%2n)
-in%most%organisms,%zygote%divides%by%mitosis,%forming%a%new%organism%with%diploid%somatic%cells
Asexual%Reproduction
Prokaryotes-binary%fission
Eukaryotes- mitosis
All%cell%division…
Signal- signal%from%in%or%outside%the%cell%that%initiated%cell%division
DNA%replication
DNA%segregation- cell%must%distribute%replicated%DNA%to%each%of%the%two%new%cells
Cytokinesis-division%of%the%cytoplasm
Binary%Fission%(Prokaryotes):
Cell%division%results%in%the%reproduction%of%an%entire%single-celled%organism
Cell%grows%in%size,%replicates%DNA,%and%then%separates%the%cytoplasm%and%DNA%into%two%new%cells
Eukaryotic%Cell%Cycle
Will%cell%enter%next%phase?
CDK%protein%is%always%present,%but%Cyclin%only%appears%at%certain%times%in%the%cell%cycle.
Cyclin%binds%to%CDK,%exposing%CDK's%active%site,%produces%signal%cascade%to%move%onto%next%phase
Cyclin%made%when%it%shouldn't%be->%cancer->%keep%dividing%and%continuing%through%the%cell%cycle
Mitosis
Goal:%Produce%two%identical%daughter%cells
Steps:
Copying%DNA
Separating%chromosomes
Separating%cell%(reforming%cell%membrane)
Homologous%chromosomes:%two%chromosomes%that%are%similar%but%
not%identical%(different%forms%of%the%same%gene,%one%from%each%
parent)
Sometimes%mitosis%in%M%
and%sometimes%meiosis
Meiosis
Goal: Produce%gametes%(cells%w/%half%DNA%of%original)
Measuring%DNA%in%cell:
Somatic%cells- 2n%and%diploid%(two%copies%of%each%chromosome- one%from%mom%and%one%from%dad)
Gametes- n%and%haploid%(1%copy%of%each%chromosome- randomly%from%mom%or%dad)
Steps:
Two%steps-Meiosis%I%and%Meiosis%II
Meiosis%I1)
Goal:%to%separate%homologous%chromosomes
Meiosis%II2)
Goal:%to%separate%sister%chromatids
Chapter%7:%Cell%Cycle%and%Cell%Division
Monday, October 23, 2017 1:49 PM
Document Summary
Goal of meiosis: produce gametes (half dna of original cells) Cell division: parent cell duplicates genetic material and divides into two similar cells. Important in growth and repair of tissues and reproduction. Asexual reproduction: offspring are clones of the parent organisms, genetically identical (ig. Sexual reproduction: fusion of two gametes, offspring have considerable genetic variation. Meiosis: cell division resulting in daughter cells with half the dna of the parent. Dna randomly separated, so daughter cells vary from each other. Cells not specialized for reproduction- somatic cells (two sets of chromosomes, and chromo homologous pairs) Gametes- single set of chromosomes, one homolog from each pair, haploid, n. Two haploid gametes fuse to form zygote in fertilization (two sets of chromosomes, diploid, 2. In most organisms, zygote divides by mitosis, forming a new organism with diploid somatic c. Eukaryotes- mitosis entical (ignoring mutation) ariation d chromosomes are in. Signal- signal from in or outside the cell that initiated cell division.
