1. 2014 CELL DIVISION - MEIOSIS Výukový materiál MB 04 - 96 Tvůrce: Mgr. Šárka Vopěnková Tvůrce anglické verze: ThMgr. Ing. Jiří Foller Projekt: S anglickým jazykem do dalších předmětů Registrační číslo: CZ.1.07/1.1.36/03.0005 Tento projekt je spolufinancován ESF a SR ČR

2.  sexual reproduction  sexual cells = gametes  gamete + gamete = zygote  zygote > germ > adult individual  gametes have got the half number of chromosomes  46 chromosomes > 2 sets each of 23 chromosome  2 sets of chromosomes = diploid cells  one set of chromosomes = haploid cells MEIOSIS

3.  meiosis completes a special type of cell cycle, by which gametes develop  meiosis = gametogenesis  interphase ( G1, S phase a G2 phase) > meiosis:  only one replication of DNA in S phase  and two cell divisions followed quickly after each other  therefore - > originated cells are haploid  meiosis = reducing division MEIOSIS

4.  a) first meiotic division = heterotypical reducing:  different from mitosis  from 1 diploid cell develop 2 haploid cells  b) second meiotic division = homeotypical:  Identical with mitosis  from 2 haploid cells develop 4 haploid cells MEIOSIS

5.  a) first meiotic division = heterotypical reducing:  prophase:  conserved nucleolus and nuclear membrane  2 sets of homological chromosomes  pair homological chromosomes attach to each other = synapsis ( „zip fastening“)  pairs of connected homological chromosomes are called bivalents MEIOSIS

6.  bivalents are four-thread formations= tetrads  recombination process – crossing – over:  reciprocal exchange of parts non-sister chromatids, which are not genetically identical  new combinations of gather and mother genes develop  synapsis ends by the isolation of homological chromosomes MEIOSIS

7.  metaphase:  equatorial plane  ! division of centromeres does not happen > neither chromosomes  anaphase:  reduction of the chromosome number > to the poles travel whole, not divided two-chromatid chromosomes  random segregation of father and mother chromosomes > various combinations in gametes MEIOSIS

8.  telophase ………  b) second meiotic division= homeotypical:  normal mitosis 2 haploid cells  prophase, metaphase, anaphase, telophase  4 haploid cells originate MEIOSIS

9.  1) reduction of chromosome number  2) recombination of father and mother genes by the process crossing – over  3) random meiotic segregation  great genetic importance MEIOSIS - SIMMARY

10.  male (haploid) + female gamete (haploid)  = diploid zygote  by multiple division of the zygote ( = more mitosis) the whole organism develops  the most cells are diploid (multicellular organisms)  lower plants (non-vascular) + bacteria are haploid MEIOSIS

11.  diversification of cells into different types  all cells have the same, complete genetic base  they use only a part of the genetic information by their specialisation DIFFERENCIATION OF CELLS

12. PROCESS OF MEIOSIS – A SCHEMA

13. Genetic schema of miotic division of cell nucleus: a – e heterotypical prophase – a)laptotene b) zygotene c) pachytene d) diplotene e) diakinesis f) heterotypical metaphase (bivalents attached to the threads of division spindle) g) heterotypical anaphase (bichromatide chromosomes from bivalents separate from each other h) homeotypical prophase i)Homeotypical metaphase j) homeotypical anaphase j) (monochromatide daughter chromosomes go to the poles of the division spindle)

14. DESCRIBE THE PICTURE

15. COMPARISON OF MITOSIS AND MEIOSIS

16. Meioza I Meio II. COMPLETE INTO THE PICTURE MEIOSIS MITOSIS

17. SOURCES  CHALUPOVÁ-KARLOVSKÁ, Vlastimila. Obecná biologie: středoškolská učebnice : evoluce, biologie buňky, genetika : s 558 řešenými testovými otázkami. 2., opr. vyd. Olomouc: Nakladatelství Olomouc, 2010, 206 s. ISBN 978-807-1822-820  KUBIŠTA, Václav. Obecná biologie: úvodní učební text biologie pro 1. ročník gymnázií. 3. upr. vyd. Praha: Fortuna, c2000, 103 s. ISBN 80-716-8714-6.  ZÁVODSKÁ, Radka. Biologie buněk: základy cytologie, bakteriologie, virologie. 1. vyd. Praha: Scientia, 2006, 160 s. ISBN 80-869-6015-3