CO OZNACZA SŁOWO MEGASPORE
Megaspore
Megaspores, zwane także makrami, są rodzajem zarodników, występujących w roślinach heterosporalnych. Te rośliny mają dwa typy zarodników, megaspory i mikrosomy. Ogólnie mówiąc, megaspore lub duże zarodniki kiełkują w żeńskim gametoficie, który wytwarza komórki jajowe. Są one zapłodnione przez plemnik wytwarzany przez męski gametofytek rozwijający się z mikrospamu. Rośliny heterosporacyjne obejmują: ▪ rośliny nasienne ▪ paprocie wodne ▪ szpiczki ...
Definicja słowa megaspore w słowniku
Definicja megaspore w słowniku to komórka roślin kwitnących, która powoduje powstanie worka zarodkowego.
KSIĄŻKI POWIĄZANE ZE SŁOWEM «MEGASPORE»
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megaspore w następujących pozycjach bibliograficznych Książki powiązane ze słowem
megaspore oraz krótkie ich fragmenty w celu przedstawienia kontekstu użycia w literaturze.
1
Paleobotany: The Biology and Evolution of Fossil Plants
It has been suggested, however, that the megaspore in these lycopsids, unlike
the megaspore of a seed, was shed from the sporangium at maturity in the typical
free-sporing manner. This assumption has been based on the occurrence of ...
Edith L. Taylor, Thomas N. Taylor, Michael Krings,
2009
2
Plant Cell Biology: Structure and Function
Introduction: In female reproduction, megaspore mother cells undergo meiosis to
give rise to four haploid cells. Only one survives as a functional megaspore.
Whereas many pollen grains develop in each anther (Plates 54, 56), megaspores
...
Brian E. S. Gunning, Martin W. Steer,
1996
3
The
Megaspore-Membrane of the Gymnosperms...
This is a reproduction of a book published before 1923.
Robert Boyd Thomson,
2012
Second, of the four haploid megaspores produced by meiosis, three consistently
abort, leaving only one func— tional megaspore. This single megaspore also
undergoes a great increase in size, correlated with the increased availability of ...
5
Aquatic and Wetland Plants of Northeastern North America, ...
A hand lens is essential for resolving megaspore ornamentation, and a
compound microscope fitted with an ocular micrometer is necessary for
determining spore diameter. Twenty megaspores should be measured to
determine average spore ...
Garrett E. Crow, Norman C. Fassett, C. Barre Hellquist,
2006
6
Conifer Reproductive Biology
Claire G. Williams. 4.4 From Megaspore and Monospory to Haploid Female
Gametophyte 61 Box 4.1 Mosaicism in the female gametophyte Rare exceptions
to monospory have been reported for several taxa. In roughly 1% of Pinus
sylvestris ...
7
INTERNATIONAL REVIEW OF CYTOLOGY
Thus, megaspores outside of the biophysical focal point may abort, whereas the
functional megaspore undergoes cenocytic development forming the
megagametophyte. The organization of the tetrad is subject to considerable
variability in ...
Scott D. Russell, Christian Dumas,
1992
8
Flora of the Northeast: A Manual of the Vascular Flora of ...
Three upper faces of megaspore with thin, somewhat parallel-walled ridges,
lower half honeycombed with coarse pits. (Fig. 14) Megaspores mostly 0.6-0. 8
mm in diameter 4. /. lacustris Megaspores mostly less than 0.6 mm in diameter 5.
Dennis W. Magee, Harry E. Ahles,
2007
:>i>; Megaspore Haustoria Fig. 310. Kinds of megaspore tetrads : A. Linear, B. T-
shaped, C. 1-shaped, D. Decussate, E. isobilateral. The megaspore mother cell
undergoes meiosis first to form a dyad and then a megaspore tetrad. During ...
10
Apomixis in Angiosperms
The functional megaspore then becomes free from callose. In addition.
megasporocytes of Gasteria verrucosai11'1l2 and other flowering plants111
provide an example of polarity in distribution of cell organelles; most are
concentrated at the ...