-
heterosporous life
cycles using microspores and
megaspores arose independently in
several plant groups during the
Devonian period.
Microspores are haploid, and are...
-
diploid microspore mother-cells,
which then
produce four
haploid microspores by meiosis.
These become pollen grains,
within which the
microspores divide...
- Freeman. Ray, Ankita. "Structure of
Microspores and the
Development of Male
Gametophyte (=
germination of
Microspores)".
Retrieved 13
April 2017. Petersen...
-
produced internally, and the
megaspores (formed
within the ovules) and the
microspores are
involved in the
formation of more
complex structures that form the...
- for the
microspores that form by
meiotic division from the
sporogenous cells. In a
process called microsporogenesis, four
haploid microspores are produced...
-
heterosporous (two
kinds of
spores are produced).: 18
These plants produce both
microspores and megaspores,
which give rise to
gametophytes that are functionally...
-
distinct sizes (heterospory or anisospory):
larger megaspores and
smaller microspores. When the two
kinds of
spore are
produced in
different kinds of sporangia...
- meiosis,
whereas in
microsporogenesis all four
microspores survive. In gymnosperms, such as conifers,
microspores are
produced through meiosis from microsporocytes...
- Like all seed plants, they are heterosporous,
having two
spore types,
microspores (male) and
megaspores (female) that are
typically produced in pollen...
- and
female cones. In the male cones,
microspores are
produced from
microsporocytes by meiosis. The
microspores develop into
pollen grains,
which contain...
