bio 402 – field biology dr. charles horn newberry college
TRANSCRIPT
BIO 402 – Field BiologyDr. Charles Horn
Newberry College
Presence of a complex reproductive structure = FLOWER
FLOWER (an organ) Commonly see both sexes together in
the same flower
Axis on which the flower parts are attached = RECEPTACLE
Four WHORLS (parts) to a flower
SEPALS – protect the developing flowercollectively called CALYXtypically green, leaf-like
PETALS – attract pollinators (transfer male reproductive cells to female reproductive cells)
collectively called COROLLA or PERIANTH
typically color related to type of pollinator
STAMENS – male reproductive composed of filament + anther
4 spore producing chambers per anther = LOCULE
CARPELS – female reproductivecollectively called PISTIL (stigma + style + ovary)
One to many chambers in each ovary each chamber = LOCULE contain OVULES one to many OVULES per locule
Diagrammatic version:
Ovule structure:a) integument (surrounding protective layer)b) embryo sac
MEGASPORE MOTHER CELL (2n) (meiosis … 3 die)
1 MEGASPORE (1n) (mitosis)
8-NUCLEATE EMBRYO SAC
3 antipodals + 2 polar nuclei1 egg cell +2 synergids +
All parts equal around receptacle = actinomorphic
Parts of different sizes = zygomorphic
PERFECT - both stamens & carpels in same flower
IMPERFECT - only one sex in a flower male and female flowers
MONOECIOUS - stamens & carpels on same plant (separate flowers)
DIOECIOUS – stamens & carpels on different plants
Based on number of flower parts
Monocots = flower parts in multiples of three (3, 6, 9 …)
Dicots = flower parts in multiples of four or five (4, 5, 8, 10 …)
Is a stem or branched system on which flowers are produced.
Can be simple (one stem with one flower = scape) or highly branched (=panicle)