Module 1: Sexual Reproduction in Flowers Flashcards
(gen) produces spores via meiosis
sporophyte
sporophyte: n or 2n
2n
(gen) germinate and divide via mitosis to produce multicellular gametophytes
spores
spore: n or 2n
n
(gen) produces gametes (egg and sperm) via mitosis
gametophyte
gametophyte: n or 2n
n
(gen) formed when gametes join; divide via mitosis to form sporophyte
zygote
zygote: n or 2n
2n
outermost whorl of flower; green leaf-like structures
sepals
set of sepals
calyx
whorl inner to the sepals
petals
set of petals
corolla
petals and sepals together
perianth
reproductive structure of angiosperms
flower
a flower is a modified ___
shoot
the 4 whorls of a flower are modified ____
leaves
flower stalk
pedicel
fleshy vegetative tissue that holds the floral parts
receptacle
3rd whorl; male reproductive structures
androecium
long projections coming out of staminal tube
stamen
stamen stalk with anthers at the tips
filament
contains microsporangia (pollen sacs) that produce pollen grains
anther
innermost whorl; female reproductive structures
gynoecium
individual unit of gynoecium; composed of stigma, style, ovary
carpel
swelling on the base of the flower
ovary
long, slender neck found inside staminal tube; connects to ovary at the base and terminates into stigma above
style
sticky structure that captures pollen
stigma
structures inside ovary which become seeds if fertilized
ovules
one carpel or many fused carpels
pistil
all 4 whorls present
complete flower
1 or more whorls missing
incomplete flower
contains both andro and gynoecium
perfect flower
contains only an andro or gynoecium
imperfect flower
plant that has both male and female flowers
monoecious plant
plant that has male and female flowers on separate plants
dioecious plant
(phase) megaspore mother cell in the megasporangium of the ovule undergoes meiosis to produce 4 haploid megaspores
megasporogenesis
(phase) suriviving megaspore divides by mitosis 3 times without cytokinesis to produce 1 cell with 8 nuclei which is then divided by membranes to form 7-celled embryo sac
megagametogenesis
diploid cell that divides into 4 haploid cells
megaspore mother cell
haploid cell; 1/4 survives
megaspore
how manty times does the surviving megaspore undergo mitosis?
3 times
how many cells are there in the embro sac?
7 cells
diploid cell that later forms endosperm
central cell
3 cells that position themselves opposite the micropyle; degenerate later on
antipodal cells
nucleus closest to micropyle
egg cell
2 nuclei on either side of egg cell; help attract and guide pollen tube
synergid cells
part of seed coat that develops from outer integument
testa
part of seed coat that develops from inner integument
tegmen
allows pollen tube to enter female gametophyte for fertilization
micropyle
(phase) diploid microsporocytes in microsporangia divide via meiosis to produce 4 haploid microspores
microsporogenesis
(phase) microspores develop into pollen grains
microgametogenesis
diploid cells found within 4 microsporangia in anther
microsporocyte
4 haploid cells that develop into pollen grains
microspores
layer of cells in the pollen sac that provides nutrition and important components to developing microspores
tapetum
smaller cell; nucleus divides by mitosis to form 2 sperm nuclei
generative cell
vegetative cell that extends through the style when pollen germinates
tube cell
thicker outer layer of pollen wall; contains sporopollenin
exine
inner layer of pollen wall
intine
complex waterproofing substance supplied by tapetal cells
sporopollenin
extension of the cytoplasm of the tube cell
pollen tube
joining of female gametophyte with 2 male gametes; ensures that endosperm only develops in ovules where egg has been fertilized
double fertilization
4 mechanisms that prevent self-fertilization
- being dioecius
- different maturity times
- structural barriers
- self-incompatibility