In message , Nick Maclaren
writes
In article ,
Stewart Robert Hinsley writes:
|
| One question arising from that, which I have been puzzled about for some
| years, is a pollen tube part of the receiving flower, or grown from the
| pollen grain? Most advanced books assume that you know that, and most
| elementary ones don't get that far ....
|
| From http://jcs.biologists.org/cgi/content/abstract/91/1/49
|
| "Two microtubule (MT) cytoskeletal systems coexist in the tubes of
| bicellular angiosperm pollens, one in the vegetative (tube) cell of the
| male gametophyte and the other in the generative cell within it."
Er, thanks, but mapping that jargon into the related by different verbiage
used by other books and papers takes me quite a lot of effort. Even parsing
that appalling sentence is bad enough! For example, does the terminal "it"
refer to the vegetative cell or the gametophyte?
Computer science papers ("not a science and nothing to do with computing")
papers are often worse, which is disgraceful for what should be an
engineering discipline, of the sort that is used by many people outside
the field. At least the area of angiosperm pollen germination physiology
is of little direct practical relevance to outsiders :-(
Regards,
Nick Maclaren.
I was assuming that you were as good as decoding the jargon as me, as I
haven't any formal training (post age 14) in biology either.
Angiosperms, as you may know, have the unusual characteristic of double
fertilisation. One sperm cell fertilizes the egg cell to produce a
diploid zygote, and the other another cell in the female gametophyte to
form the diploid or triploid (depending on clade) endosperm. Angiosperm
pollens either have two or three cells; a vegetative cell, and either
two sperm cells, or a generative cell which divides, post-germination,
into two sperm cells. The reference to bicellular angiosperm pollens
refers to the latter case. The vegetative cell encloses the other cell
or cells.
The key point in the quoted sentence is the reference to the vegetative
cell of the male gametophyte (pollen grain) as a tube cell.
(I've made a start on botancal jargon -
http://www.malvaceae.info/Biology/SexDistribution.html - but I haven't
finished the pages on pollen development and morphology.)
--
Stewart Robert Hinsley