Submit Search
Upload
cytology-mitosis-and-meiosis.pptx
•
Download as PPTX, PDF
•
0 likes
•
5 views
G
greed first
Follow
meoisis and mitosis ppt
Read less
Read more
Science
Report
Share
Report
Share
1 of 32
Download now
Recommended
Conditions: Chromosome number anomalies
Conditions: Chromosome number anomalies
meducationdotnet
Explanation slides Somatic Mutations cancer
Explanation slides Somatic Mutations cancer
meducationdotnet
Meiosis
Meiosis
University of Johannesburg
Biology! Meiosis
Biology! Meiosis
Sibongile Slinda
Unit 3 meiosis
Unit 3 meiosis
Mildred Mashau from UJ
Unit 3 meiosis
Unit 3 meiosis
ayanda hlope
Unit 3 meiosis
Unit 3 meiosis
university of johannesburg
Unit%203%20 meiosis[1]
Unit%203%20 meiosis[1]
sinegugulethu
Recommended
Conditions: Chromosome number anomalies
Conditions: Chromosome number anomalies
meducationdotnet
Explanation slides Somatic Mutations cancer
Explanation slides Somatic Mutations cancer
meducationdotnet
Meiosis
Meiosis
University of Johannesburg
Biology! Meiosis
Biology! Meiosis
Sibongile Slinda
Unit 3 meiosis
Unit 3 meiosis
Mildred Mashau from UJ
Unit 3 meiosis
Unit 3 meiosis
ayanda hlope
Unit 3 meiosis
Unit 3 meiosis
university of johannesburg
Unit%203%20 meiosis[1]
Unit%203%20 meiosis[1]
sinegugulethu
Unit 3 meiosis
Unit 3 meiosis
Nomfundo Thamane
Unit 3 meiosis
Unit 3 meiosis
Moses Mothoagae
Unit 3 meiosis
Unit 3 meiosis
Nkosingiphile Ximba
Unit 3 meiosis
Unit 3 meiosis
Lwazi Simelane
Unit 3 meiosis
Unit 3 meiosis
science91
Unit 3 meiosis
Unit 3 meiosis
siphesihle gloria Hlongwane
Liife sciences....meiosis
Liife sciences....meiosis
Lungileh Ngobese
Unit 3 meiosis
Unit 3 meiosis
sphiwe benedicta mhlaba
Clinical Photos - Chromosome structure abnormality
Clinical Photos - Chromosome structure abnormality
meducationdotnet
Test PPT 20140429
Test PPT 20140429
meducationdotnet
13 ge lecture presentation
13 ge lecture presentation
mahmood jassim
Presentation1 dudrah
Presentation1 dudrah
Dudrah Moyo
Chapter 8 Bio
Chapter 8 Bio
descartin
Karyotypes - Various
Karyotypes - Various
meducationdotnet
J Oral Maxillofac Pathol. 2014 Sep; 18(Suppl 1) S2–S5. do.docx
J Oral Maxillofac Pathol. 2014 Sep; 18(Suppl 1) S2–S5. do.docx
christiandean12115
Meiosis
Meiosis
Danelle Oosthuizen
08 lecture presentation
08 lecture presentation
Uconn Stamford
Conditions Cancer familial bowel FAP
Conditions Cancer familial bowel FAP
meducationdotnet
Biology form 4 chapter 5 cell dvision part 2 (meiosis)
Biology form 4 chapter 5 cell dvision part 2 (meiosis)
Nirmala Josephine
CHAPTER4The-Biological-And-Environmental-Causes-of-DisabilitiesMgaPogiNagPres...
CHAPTER4The-Biological-And-Environmental-Causes-of-DisabilitiesMgaPogiNagPres...
jaysonablao0703
INTEGRITY_Fontanos-and-Salubre.pdf
INTEGRITY_Fontanos-and-Salubre.pdf
greed first
Social Support and Services.pdf
Social Support and Services.pdf
greed first
More Related Content
Similar to cytology-mitosis-and-meiosis.pptx
Unit 3 meiosis
Unit 3 meiosis
Nomfundo Thamane
Unit 3 meiosis
Unit 3 meiosis
Moses Mothoagae
Unit 3 meiosis
Unit 3 meiosis
Nkosingiphile Ximba
Unit 3 meiosis
Unit 3 meiosis
Lwazi Simelane
Unit 3 meiosis
Unit 3 meiosis
science91
Unit 3 meiosis
Unit 3 meiosis
siphesihle gloria Hlongwane
Liife sciences....meiosis
Liife sciences....meiosis
Lungileh Ngobese
Unit 3 meiosis
Unit 3 meiosis
sphiwe benedicta mhlaba
Clinical Photos - Chromosome structure abnormality
Clinical Photos - Chromosome structure abnormality
meducationdotnet
Test PPT 20140429
Test PPT 20140429
meducationdotnet
13 ge lecture presentation
13 ge lecture presentation
mahmood jassim
Presentation1 dudrah
Presentation1 dudrah
Dudrah Moyo
Chapter 8 Bio
Chapter 8 Bio
descartin
Karyotypes - Various
Karyotypes - Various
meducationdotnet
J Oral Maxillofac Pathol. 2014 Sep; 18(Suppl 1) S2–S5. do.docx
J Oral Maxillofac Pathol. 2014 Sep; 18(Suppl 1) S2–S5. do.docx
christiandean12115
Meiosis
Meiosis
Danelle Oosthuizen
08 lecture presentation
08 lecture presentation
Uconn Stamford
Conditions Cancer familial bowel FAP
Conditions Cancer familial bowel FAP
meducationdotnet
Biology form 4 chapter 5 cell dvision part 2 (meiosis)
Biology form 4 chapter 5 cell dvision part 2 (meiosis)
Nirmala Josephine
CHAPTER4The-Biological-And-Environmental-Causes-of-DisabilitiesMgaPogiNagPres...
CHAPTER4The-Biological-And-Environmental-Causes-of-DisabilitiesMgaPogiNagPres...
jaysonablao0703
Similar to cytology-mitosis-and-meiosis.pptx
(20)
Unit 3 meiosis
Unit 3 meiosis
Unit 3 meiosis
Unit 3 meiosis
Unit 3 meiosis
Unit 3 meiosis
Unit 3 meiosis
Unit 3 meiosis
Unit 3 meiosis
Unit 3 meiosis
Unit 3 meiosis
Unit 3 meiosis
Liife sciences....meiosis
Liife sciences....meiosis
Unit 3 meiosis
Unit 3 meiosis
Clinical Photos - Chromosome structure abnormality
Clinical Photos - Chromosome structure abnormality
Test PPT 20140429
Test PPT 20140429
13 ge lecture presentation
13 ge lecture presentation
Presentation1 dudrah
Presentation1 dudrah
Chapter 8 Bio
Chapter 8 Bio
Karyotypes - Various
Karyotypes - Various
J Oral Maxillofac Pathol. 2014 Sep; 18(Suppl 1) S2–S5. do.docx
J Oral Maxillofac Pathol. 2014 Sep; 18(Suppl 1) S2–S5. do.docx
Meiosis
Meiosis
08 lecture presentation
08 lecture presentation
Conditions Cancer familial bowel FAP
Conditions Cancer familial bowel FAP
Biology form 4 chapter 5 cell dvision part 2 (meiosis)
Biology form 4 chapter 5 cell dvision part 2 (meiosis)
CHAPTER4The-Biological-And-Environmental-Causes-of-DisabilitiesMgaPogiNagPres...
CHAPTER4The-Biological-And-Environmental-Causes-of-DisabilitiesMgaPogiNagPres...
More from greed first
INTEGRITY_Fontanos-and-Salubre.pdf
INTEGRITY_Fontanos-and-Salubre.pdf
greed first
Social Support and Services.pdf
Social Support and Services.pdf
greed first
Liquids.pdf
Liquids.pdf
greed first
BELIEF_Castor & Alilain.pdf
BELIEF_Castor & Alilain.pdf
greed first
Optimism 🤩🤩.pdf
Optimism 🤩🤩.pdf
greed first
choices (1).pdf
choices (1).pdf
greed first
aquatic-and-physical-therapy-center.pptx
aquatic-and-physical-therapy-center.pptx
greed first
6-The-1888-Controversy.pptx
6-The-1888-Controversy.pptx
greed first
Theology-and-Principles-of-Health-PPT-template.pptx
Theology-and-Principles-of-Health-PPT-template.pptx
greed first
Biochem-Laboratory-42.docx
Biochem-Laboratory-42.docx
greed first
ECHINOCOCCUS GRANULOSUS.pdf
ECHINOCOCCUS GRANULOSUS.pdf
greed first
Chap17 Carboxylic Acids (1).pdf
Chap17 Carboxylic Acids (1).pdf
greed first
ch11_lecture_blood.pdf
ch11_lecture_blood.pdf
greed first
Amines.pptx
Amines.pptx
greed first
ASMIA BIO SILI.docx
ASMIA BIO SILI.docx
greed first
REPORT.docx
REPORT.docx
greed first
More from greed first
(16)
INTEGRITY_Fontanos-and-Salubre.pdf
INTEGRITY_Fontanos-and-Salubre.pdf
Social Support and Services.pdf
Social Support and Services.pdf
Liquids.pdf
Liquids.pdf
BELIEF_Castor & Alilain.pdf
BELIEF_Castor & Alilain.pdf
Optimism 🤩🤩.pdf
Optimism 🤩🤩.pdf
choices (1).pdf
choices (1).pdf
aquatic-and-physical-therapy-center.pptx
aquatic-and-physical-therapy-center.pptx
6-The-1888-Controversy.pptx
6-The-1888-Controversy.pptx
Theology-and-Principles-of-Health-PPT-template.pptx
Theology-and-Principles-of-Health-PPT-template.pptx
Biochem-Laboratory-42.docx
Biochem-Laboratory-42.docx
ECHINOCOCCUS GRANULOSUS.pdf
ECHINOCOCCUS GRANULOSUS.pdf
Chap17 Carboxylic Acids (1).pdf
Chap17 Carboxylic Acids (1).pdf
ch11_lecture_blood.pdf
ch11_lecture_blood.pdf
Amines.pptx
Amines.pptx
ASMIA BIO SILI.docx
ASMIA BIO SILI.docx
REPORT.docx
REPORT.docx
Recently uploaded
Manassas R - Parkside Middle School 🌎🏫
Manassas R - Parkside Middle School 🌎🏫
qfactory1
Artificial Intelligence In Microbiology by Dr. Prince C P
Artificial Intelligence In Microbiology by Dr. Prince C P
PRINCE C P
Is RISC-V ready for HPC workload? Maybe?
Is RISC-V ready for HPC workload? Maybe?
Patrick Diehl
Call Girls in Aiims Metro Delhi 💯Call Us 🔝9953322196🔝 💯Escort.
Call Girls in Aiims Metro Delhi 💯Call Us 🔝9953322196🔝 💯Escort.
aasikanpl
Bentham & Hooker's Classification. along with the merits and demerits of the ...
Bentham & Hooker's Classification. along with the merits and demerits of the ...
Nistarini College, Purulia (W.B) India
insect anatomy and insect body wall and their physiology
insect anatomy and insect body wall and their physiology
DrAnita Sharma
Behavioral Disorder: Schizophrenia & it's Case Study.pdf
Behavioral Disorder: Schizophrenia & it's Case Study.pdf
SELF-EXPLANATORY
Microphone- characteristics,carbon microphone, dynamic microphone.pptx
Microphone- characteristics,carbon microphone, dynamic microphone.pptx
priyankatabhane
Best Call Girls In Sector 29 Gurgaon❤️8860477959 EscorTs Service In 24/7 Delh...
Best Call Girls In Sector 29 Gurgaon❤️8860477959 EscorTs Service In 24/7 Delh...
lizamodels9
Scheme-of-Work-Science-Stage-4 cambridge science.docx
Scheme-of-Work-Science-Stage-4 cambridge science.docx
yaramohamed343013
Twin's paradox experiment is a meassurement of the extra dimensions.pptx
Twin's paradox experiment is a meassurement of the extra dimensions.pptx
Eran Akiva Sinbar
LIGHT-PHENOMENA-BY-CABUALDIONALDOPANOGANCADIENTE-CONDEZA (1).pptx
LIGHT-PHENOMENA-BY-CABUALDIONALDOPANOGANCADIENTE-CONDEZA (1).pptx
malonesandreagweneth
Call Girls in Munirka Delhi 💯Call Us 🔝8264348440🔝
Call Girls in Munirka Delhi 💯Call Us 🔝8264348440🔝
soniya singh
TOTAL CHOLESTEROL (lipid profile test).pptx
TOTAL CHOLESTEROL (lipid profile test).pptx
dharshini369nike
Engler and Prantl system of classification in plant taxonomy
Engler and Prantl system of classification in plant taxonomy
Nistarini College, Purulia (W.B) India
Spermiogenesis or Spermateleosis or metamorphosis of spermatid
Spermiogenesis or Spermateleosis or metamorphosis of spermatid
Sarthak Sekhar Mondal
Hot Sexy call girls in Moti Nagar,🔝 9953056974 🔝 escort Service
Hot Sexy call girls in Moti Nagar,🔝 9953056974 🔝 escort Service
9953056974 Low Rate Call Girls In Saket, Delhi NCR
Neurodevelopmental disorders according to the dsm 5 tr
Neurodevelopmental disorders according to the dsm 5 tr
ssuser06f238
Call Girls in Hauz Khas Delhi 💯Call Us 🔝9953322196🔝 💯Escort.
Call Girls in Hauz Khas Delhi 💯Call Us 🔝9953322196🔝 💯Escort.
aasikanpl
Call Girls In Nihal Vihar Delhi ❤️8860477959 Looking Escorts In 24/7 Delhi NCR
Call Girls In Nihal Vihar Delhi ❤️8860477959 Looking Escorts In 24/7 Delhi NCR
lizamodels9
Recently uploaded
(20)
Manassas R - Parkside Middle School 🌎🏫
Manassas R - Parkside Middle School 🌎🏫
Artificial Intelligence In Microbiology by Dr. Prince C P
Artificial Intelligence In Microbiology by Dr. Prince C P
Is RISC-V ready for HPC workload? Maybe?
Is RISC-V ready for HPC workload? Maybe?
Call Girls in Aiims Metro Delhi 💯Call Us 🔝9953322196🔝 💯Escort.
Call Girls in Aiims Metro Delhi 💯Call Us 🔝9953322196🔝 💯Escort.
Bentham & Hooker's Classification. along with the merits and demerits of the ...
Bentham & Hooker's Classification. along with the merits and demerits of the ...
insect anatomy and insect body wall and their physiology
insect anatomy and insect body wall and their physiology
Behavioral Disorder: Schizophrenia & it's Case Study.pdf
Behavioral Disorder: Schizophrenia & it's Case Study.pdf
Microphone- characteristics,carbon microphone, dynamic microphone.pptx
Microphone- characteristics,carbon microphone, dynamic microphone.pptx
Best Call Girls In Sector 29 Gurgaon❤️8860477959 EscorTs Service In 24/7 Delh...
Best Call Girls In Sector 29 Gurgaon❤️8860477959 EscorTs Service In 24/7 Delh...
Scheme-of-Work-Science-Stage-4 cambridge science.docx
Scheme-of-Work-Science-Stage-4 cambridge science.docx
Twin's paradox experiment is a meassurement of the extra dimensions.pptx
Twin's paradox experiment is a meassurement of the extra dimensions.pptx
LIGHT-PHENOMENA-BY-CABUALDIONALDOPANOGANCADIENTE-CONDEZA (1).pptx
LIGHT-PHENOMENA-BY-CABUALDIONALDOPANOGANCADIENTE-CONDEZA (1).pptx
Call Girls in Munirka Delhi 💯Call Us 🔝8264348440🔝
Call Girls in Munirka Delhi 💯Call Us 🔝8264348440🔝
TOTAL CHOLESTEROL (lipid profile test).pptx
TOTAL CHOLESTEROL (lipid profile test).pptx
Engler and Prantl system of classification in plant taxonomy
Engler and Prantl system of classification in plant taxonomy
Spermiogenesis or Spermateleosis or metamorphosis of spermatid
Spermiogenesis or Spermateleosis or metamorphosis of spermatid
Hot Sexy call girls in Moti Nagar,🔝 9953056974 🔝 escort Service
Hot Sexy call girls in Moti Nagar,🔝 9953056974 🔝 escort Service
Neurodevelopmental disorders according to the dsm 5 tr
Neurodevelopmental disorders according to the dsm 5 tr
Call Girls in Hauz Khas Delhi 💯Call Us 🔝9953322196🔝 💯Escort.
Call Girls in Hauz Khas Delhi 💯Call Us 🔝9953322196🔝 💯Escort.
Call Girls In Nihal Vihar Delhi ❤️8860477959 Looking Escorts In 24/7 Delhi NCR
Call Girls In Nihal Vihar Delhi ❤️8860477959 Looking Escorts In 24/7 Delhi NCR
cytology-mitosis-and-meiosis.pptx
1.
© 2009 NHS
National Genetics Education and Development Centre Genetics and Genomics for Healthcare www.geneticseducation.nhs.uk Mitosis and Meiosis This PowerPoint file contains a number of slides that may be useful for teaching of genetics concepts. You may use these slides and their contents for non-commercial educational purposes. This presentation contains diagrams of: • Mitosis • Meiosis • Meiotic non-disjunction
2.
© 2009 NHS
National Genetics Education and Development Centre Genetics and Genomics for Healthcare www.geneticseducation.nhs.uk What is the purpose of mitosis? Cell division Products genetically identical Growth of organism
3.
© 2009 NHS
National Genetics Education and Development Centre Genetics and Genomics for Healthcare www.geneticseducation.nhs.uk
4.
© 2009 NHS
National Genetics Education and Development Centre Genetics and Genomics for Healthcare www.geneticseducation.nhs.uk Fig. 2.6 ©Scion Publishing Ltd The stages of mitosis See next slides for individual stages
5.
© 2009 NHS
National Genetics Education and Development Centre Genetics and Genomics for Healthcare www.geneticseducation.nhs.uk
6.
© 2009 NHS
National Genetics Education and Development Centre Genetics and Genomics for Healthcare www.geneticseducation.nhs.uk
7.
© 2009 NHS
National Genetics Education and Development Centre Genetics and Genomics for Healthcare www.geneticseducation.nhs.uk
8.
© 2009 NHS
National Genetics Education and Development Centre Genetics and Genomics for Healthcare www.geneticseducation.nhs.uk
9.
© 2009 NHS
National Genetics Education and Development Centre Genetics and Genomics for Healthcare www.geneticseducation.nhs.uk Meiosis • Function Reduction division (23 chromosomes per gamete) reassortment of genes by: • crossing-over • independent segregation of chromosomes • Mechanism Each homologue (e.g. “chromosome 7”) replicates to give two sister chromatids Homologues pair (e.g. maternal chromosome 7 and paternal chromosome 7) Exchange of material between non-sister chromatids: crossing-over, recombination Chiasmata (visible cytologically) are the physical manifestations of crossing-over
10.
© 2009 NHS
National Genetics Education and Development Centre Genetics and Genomics for Healthcare www.geneticseducation.nhs.uk A homologous pair of parental chromosomes (e.g. chromosome 7) In meiosis I each chromosome duplicates producing two sister chromatids Crossing-over (Recombination) Gene re-assortment by crossing-over meiosis II
11.
© 2009 NHS
National Genetics Education and Development Centre Genetics and Genomics for Healthcare www.geneticseducation.nhs.uk Each spermatogonium in the testis at age 15 is the result of 30 previous cell divisions This spermatogonium maintains the stock of spermatogonia and continues to divide Four spermatozoa Every 16 days from puberty At the age of 25: 310 cell divisions have had to occur to produce a particular sperm. The number of cell divisions required to produce a human sperm Four spermatozoa
12.
© 2009 NHS
National Genetics Education and Development Centre Genetics and Genomics for Healthcare www.geneticseducation.nhs.uk MEIOSIS I Each spermatogonium in testis at age 15 is result of 30 previous mitotic cell divisions Pool of spermatogonia maintained and continues to divide 4 spermatozoa (Every 16 days from puberty) At the age of 25: 310 cell divisions have had to occur to produce a particular sperm. The number of cell divisions required to produce a human sperm primary spermatocyte SG SG SG SC SC secondary spermatocytes MEIOSIS II SC 4 spermatids differentiation MITOSIS SG
13.
© 2009 NHS
National Genetics Education and Development Centre Genetics and Genomics for Healthcare www.geneticseducation.nhs.uk 22 mitotic cell divisions by 5 months gestation to make a stock of 2,600,000 oocytes Each month one is ovulated MEIOSIS I completed at ovulation Polar body Meiosis II completed at fertilisation 2nd polar body Zygote The number of cell divisions required to produce a human egg cell
14.
© 2009 NHS
National Genetics Education and Development Centre Genetics and Genomics for Healthcare www.geneticseducation.nhs.uk The stock of oocytes is ready by 5 months gestation. Each remains in maturation arrest at the crossing-over stage until ovulation Each month one is ovulated Meiosis I not completed until ovulation Polar body Meiosis II not completed until fertilisation 2nd polar body Zygote Oocytes, time and the completion of meiosis There may be a lengthy interval between onset and completion of meiosis (up to 50 years later) Accumulating effects on the primary oocyte during this phase may damage the cell’s spindle formation and repair mechanisms predisposing to non-disjunction.
15.
© 2009 NHS
National Genetics Education and Development Centre Genetics and Genomics for Healthcare www.geneticseducation.nhs.uk
16.
© 2009 NHS
National Genetics Education and Development Centre Genetics and Genomics for Healthcare www.geneticseducation.nhs.uk Fig. 2.7 ©Scion Publishing Ltd The stages of meiosis. Meiosis is used only for the production of sperm and eggs. It consists of two successive cell divisions, producing four daughter cells (although in oogenesis only one of these develops into a mature oocyte; the others form the polar bodies). Meiosis has two main functions: to reduce the chromosome number in the gamete to 23, and to ensure that every gamete is genetically unique.
17.
© 2009 NHS
National Genetics Education and Development Centre Genetics and Genomics for Healthcare www.geneticseducation.nhs.uk
18.
© 2009 NHS
National Genetics Education and Development Centre Genetics and Genomics for Healthcare www.geneticseducation.nhs.uk
19.
© 2009 NHS
National Genetics Education and Development Centre Genetics and Genomics for Healthcare www.geneticseducation.nhs.uk Fig. 2.8 © Scion Publishing Ltd Examples of chromosomes during meiosis. (a) Two cells from a testicular biopsy showing chromosomes during prophase I of male meiosis. Each of the 23 structures is a bivalent, consisting of two homologous chromosomes, each having two chromatids. Note the end-to-end pairing of the X and Y chromosomes. (b) A bivalent seen in meiosis in an amphibian, which has large chromosomes that make the four- stranded structure clear.
20.
© 2009 NHS
National Genetics Education and Development Centre Genetics and Genomics for Healthcare www.geneticseducation.nhs.uk Fig. 2.12 © Scion Publishing Ltd The effects of non-disjunction in meiosis. The non-disjunction involves only the single pair of chromosomes (meiosis I) or the single chromosome (meiosis II) shown; all the other chromosomes (not shown) disjoin and segregate normally.
21.
© 2009 NHS
National Genetics Education and Development Centre Genetics and Genomics for Healthcare www.geneticseducation.nhs.uk Fig. 2.17 ©Scion Publishing Ltd Possible ways the chromosomes could segregate in the first meiotic division. During prophase 1, matching chromosome segments pair, resulting in a cross-shaped tetravalent containing the normal and translocated copies of chromosomes 1 and 22. At anaphase 1 they pull apart, and the diagram shows various ways this could happen. The gamete that gave rise to Baby Elliot is circled. Other more complex segregation patterns (3:1 segregation) are also possible.
22.
© 2009 NHS
National Genetics Education and Development Centre Genetics and Genomics for Healthcare www.geneticseducation.nhs.uk Fig. 2.21 ©Scion Publishing Ltd During meiosis I matching chromosome segments pair. If one chromosome has an inversion compared to its homolog, they usually form a looped structure.
23.
© 2009 NHS
National Genetics Education and Development Centre Genetics and Genomics for Healthcare www.geneticseducation.nhs.uk
24.
© 2009 NHS
National Genetics Education and Development Centre Genetics and Genomics for Healthcare www.geneticseducation.nhs.uk Normal monosomic gametes Normal meiosis Reduction division MEIOSIS I MEIOSIS II Results of crossing-over not shown Replicate DNA
25.
© 2009 NHS
National Genetics Education and Development Centre Genetics and Genomics for Healthcare www.geneticseducation.nhs.uk MEIOSIS I MEIOSIS II Results of crossing-over not shown Replicate DNA Nondisjunction during meiosis I Non-disjunction Disomic gametes Nullisomic gametes
26.
© 2009 NHS
National Genetics Education and Development Centre Genetics and Genomics for Healthcare www.geneticseducation.nhs.uk MEIOSIS I MEIOSIS II Results of crossing-over not shown Replicate DNA Nondisjunction during meiosis II Non-disjunction Disomic Nullisomic Monosomic Monosomic gametes
27.
© 2009 NHS
National Genetics Education and Development Centre Genetics and Genomics for Healthcare www.geneticseducation.nhs.uk Parental origin of meiotic error leading to aneuploidy Chromosome abnormality Paternal (%) Maternal (%) Trisomy 21 (Down) 15 85 Trisomy 18 (Edwards) 10 90 Trisomy 13 (Patau) 15 85 45,X (Turner) 80 20 47,XXX 5 95 47,XXY 45 55 47,XYY 100 0
28.
© 2009 NHS
National Genetics Education and Development Centre Genetics and Genomics for Healthcare www.geneticseducation.nhs.uk New mutations: increase with paternal age 0 1 2 3 4 5 24 29 34 39 44 47 Paternal age Relative frequency Marfan Achondroplasia Higher mutation rates in males are likely to be related to the greater number of germ cell divisions
29.
© 2009 NHS
National Genetics Education and Development Centre Genetics and Genomics for Healthcare www.geneticseducation.nhs.uk Meiosis Animation from Tokyo Medical University Genetics Study Group Hironao NUMABE, M.D
30.
© 2009 NHS
National Genetics Education and Development Centre Genetics and Genomics for Healthcare www.geneticseducation.nhs.uk Non-disjunction in meiosis I resulting in trisomy 21 Down syndrome Animation from Tokyo Medical University Genetics Study Group Hironao NUMABE, M.D
31.
© 2009 NHS
National Genetics Education and Development Centre Genetics and Genomics for Healthcare www.geneticseducation.nhs.uk Normal disomy Mitosis Non-disjunction Normal disomy Trisomy Monosomy (lethal to cell) Somatic mosaicism (eg trisomy 21) as a result of mitotic non-disjunction
32.
© 2009 NHS
National Genetics Education and Development Centre Genetics and Genomics for Healthcare www.geneticseducation.nhs.uk Meiotic Non-disjunction (Trisomy 21: 75% meiosis 1) Trisomy Monosomy (lethal)
Download now