2024 Tus sau: Elizabeth Oswald | [email protected]. Kawg hloov kho: 2024-01-13 00:07
Teb tiav: Thaum lub sijhawm microsporogenesis, meiosis tshwm sim hauv microspore niam hlwb. Thaum lub anther tseem hluas, ib pab pawg ntawm cov kab mob sib xyaw ua ke nyob hauv nruab nrab ntawm txhua microsporangium. Cov hlwb hauv nruab nrab no tso rau hauv microsporangium tsim cov 'sporogenous cov ntaub so ntswg'.
Microsporogenesis Nws tshwm sim qhov twg?
Kev tsim ntawm microspores hauv microsporangia (lossis paj paj sacs) ntawm cov noob nroj tsuag. Ib lub cell diploid nyob rau hauv microsporangium, hu ua microsporocyte los yog paj ntoos niam cell, nkag mus rau meiosis thiab ua rau muaj plaub haploid microspores.
YMeiosis hauv Microsporogenesis yog dab tsi?
Microsporogenesis lossis txiv neej meiosis yog theem ntxov tshaj plaws hauv paj ntoos ontogeny. Nws muaj cov kev faib tawm nuclear cuam tshuam nrog cytoplasmic divisions lossis cytokinesis. Cov txheej txheem no pib nrog microsporocytes lossis paj paj noob qes nyob rau hauv lub hnab ntawv callose nyob rau hauv uas meiosis tshwm sim.
Muaj pes tsawg mitosis thiab meiosis tshwm sim hauv Microsporogenesis?
Ib qho kev faib meiotic thiab ib qho kev faib mitotic muaj nyob hauv microsporogenesis.
Yuav ua li cas thaum Microsporogenesis?
Microsporogenesis suav nrog cov xwm txheej uas ua rau tsim cov haploid unicellular microspores. Thaum lub sij hawm microsporogenesis lub diploid sporogenous hlwb txawv li microsporocytes (pollen niam hlwb lossismeiocytes) uas faib los ntawm meiosis los ua plaub haploid microspores.
Pom zoo:
Lub sijhawm twg cov ammonite tshwm sim hauv ntiaj teb?
Ammonites nyob rau lub sijhawm ntawm Ntiaj Teb keeb kwm hu ua the Jurassic thiab Cretaceous. Ua ke, cov no sawv cev rau lub sijhawm luv ntawm txog 140 lab xyoo. Lub Sijhawm Jurassic tau pib txog 201 lab xyoo dhau los thiab Cretaceous Lub Sijhawm xaus li 66 lab xyoo dhau los.
Lub sijhawm calvin lub voj voog twg ntawm cov hauv qab no tshwm sim?
Qhov twg hauv qab no tshwm sim thaum Calvin lub voj voog ntawm photosynthesis? Cov pa roj carbon dioxide hloov mus rau cov tshuaj uas tuaj yeem siv los ua suab thaj. Koj nyuam qhuav kawm 50 nqe lus! Dab tsi tshwm sim thaum lub caij Calvin?
Lub sijhawm meiosis hla dhau tshwm sim ntawm?
Kev hla dhau tshwm sim thaum prophase I ntawm meiosis ua ntej tetrads tau ua raws li txoj kab nruab nrab hauv metaphase I. Los ntawm meiosis II, tsuas yog viv ncaus chromatids tseem nyob thiab homologous chromosomes tau tsiv mus rau cais cov hlwb.
Lub sijhawm meiosis thaum twg kev sib tw ntawm chromosomes tshwm sim?
Thaum lub sijhawm prophase I, cov chromosomes condense thiab pom hauv lub nucleus. Vim tias txhua tus chromosome tau muab luam tawm thaum lub sijhawm the S theem uas tau tshwm sim ua ntej prophase I, txhua tus tam sim no muaj ob tus muam chromatids koom nrog ntawm centromere.
Lub sijhawm kuv lub sijhawm dawb lossis thaum kuv lub sijhawm dawb?
yog li, qhov no txhais tau tias "thaum kuv lub sijhawm dawb" tsis siv ntauthiab koj muab "hauv kuv lub sijhawm dawb" ntau dua nyob rau qhov kawg ntawm kab lus. Piv txwv li: Kuv tau taug kev tus dev thaum kuv lub sijhawm dawb.
