How To Use Nucellus In A Sentence
-
The entrance of pollen-tubes into the nucellus by the chalaza, instead of through the micropyle, was first fully demonstrated by Treub in his paper "Sur les
More Letters of Charles Darwin — Volume 2
-
Only one pollen tube tip entered the nucellus through the micropyle.
-
(Liliaceae) polyembryony results from an adventitious production of embryos from the cells of the nucellus around the top of the embryo-sac.
Encyclopaedia Britannica, 11th Edition, Volume 2, Part 1, Slice 1
-
The nucellus is a cellular tissue enveloping one large cell, the embryo-sac or macrospore.
Encyclopaedia Britannica, 11th Edition, Volume 2, Part 1, Slice 1
-
In some cases the embryo or the embryo-sac sends out suckers into the nucellus and ovular integument.
Encyclopaedia Britannica, 11th Edition, Volume 2, Part 1, Slice 1
-
During sexual megagametophytic development (with the embryo sac as the megagametophyte and the egg cell as megagamete), a sub-epidermal cell of the nucellus tissue differentiates into a megaspore-mother cell which undergoes meiosis I and II to form four megaspores.
-
In addition, the grains were observed to float in water with sacci uppermost, consistent with the suggestion that distally placed sacci serve to orientate the germinal furrow of the pollen grain towards the nucellus of an inverted ovule.
-
The development of the ovule, which represents the macrosporangium, is very similar to the process in Gymnosperms; when mature it consists of one or two coats surrounding the central nucellus, except at the apex where an opening, the micropyle, is left.
Encyclopaedia Britannica, 11th Edition, Volume 2, Part 1, Slice 1
-
The plants included are, however, mainly well-established parasites, and the absence of nucellus is only one of those characters of reduction to which parasites are liable.
Encyclopaedia Britannica, 11th Edition, Volume 2, Part 1, Slice 1
-
In some plants the nucellus is not thus absorbed, but itself becomes a seat of deposit of reserve-food constituting the _perisperm_ which may coexist with endosperm, as in the water-lily order, or may alone form a food-reserve for the embryo, as in _Canna_.
Encyclopaedia Britannica, 11th Edition, Volume 2, Part 1, Slice 1
-
A nucellar dome has been formed in the massive nucellar cap and the integument has overgrown the nucellus and formed a wide-open micropyle.
-
A protractor was used to measure the angle of this line to the transverse line and hence the angle to the apex of the nucellus.
-
Ovular characters determine the grouping in the Dicotyledons, van Tieghem supporting the view that the integument, the outer if there be two, is the lamina of a leaf of which the funicle is the petiole, whilst the nucellus is an outgrowth of this leaf, and the inner integument, if present, an indusium.
Encyclopaedia Britannica, 11th Edition, Volume 2, Part 1, Slice 1
-
In some plants the nucellus is not thus absorbed, but itself becomes a seat of deposit of reserve-food constituting the _perisperm_ which may coexist with endosperm, as in the water-lily order, or may alone form a food-reserve for the embryo, as in _Canna_.
Encyclopaedia Britannica, 11th Edition, Volume 2, Part 1, Slice 1
-
Insemineae include forms in which the nucellus is not developed, and therefore there can be no seed.
Encyclopaedia Britannica, 11th Edition, Volume 2, Part 1, Slice 1
-
As the development of embryo and endosperm proceeds within the embryo-sac, its wall enlarges and commonly absorbs the substance of the nucellus (which is likewise enlarging) to near its outer limit, and combines with it and the integument to form the _seed-coat_; or the whole nucellus and even the integument may be absorbed.
Encyclopaedia Britannica, 11th Edition, Volume 2, Part 1, Slice 1
-
The inner integument initiates as a ring of cells around the circumference of the ovule primordium and exhibits symmetrical cylindrical growth until it surrounds and encases the nucellus.
-
At this stage the triploid endosperm nuclei are approximately the same size as the diploid nuclei of the pericarp and nucellus.
-
In a species of _Allium_, embryos have been found developing in the same individual from the egg-cell, synergids, antipodal cells and cells of the nucellus.
Encyclopaedia Britannica, 11th Edition, Volume 2, Part 1, Slice 1
-
Other barriers may also exist because xylem-mobile safranin failed to enter the ovary although the xylem passes around the nucellus and into the stylar tissue.
-
(Liliaceae) polyembryony results from an adventitious production of embryos from the cells of the nucellus around the top of the embryo-sac.
Encyclopaedia Britannica, 11th Edition, Volume 2, Part 1, Slice 1
-
Ovular characters determine the grouping in the Dicotyledons, van Tieghem supporting the view that the integument, the outer if there be two, is the lamina of a leaf of which the funicle is the petiole, whilst the nucellus is an outgrowth of this leaf, and the inner integument, if present, an indusium.
Encyclopaedia Britannica, 11th Edition, Volume 2, Part 1, Slice 1
-
Other barriers may also exist because xylem-mobile safranin failed to enter the ovary although the xylem passes around the nucellus and into the stylar tissue.
-
Within the ovary, pollen tubes also grew in the ECM to penetrate the micropyle and subsequently grew intercellularly within the nucellus up to the embryo sac.
-
Diboll and Larson report that there are no plasmodesmata connecting the nucellus to the embryo sac.
-
Ovules consisted of an outer integument that surrounded the inner integument to form the micropyle, with the inner integument surrounding the nucellus and embryo sac.
-
Instead, it appears that there is a barrier to movement between the post-phloem symplast and the nucellus.
-
In wheat, evidence was found that a barrier occurred in the chalaza, a small zone of cells between the maternal vascular tissue and the nucellus.