Seed Plants-Chapter 31 Flashcards
seed plants evolved from spore-bearing plants known as _______________
progymnosperms
What are the function of the seed?
(1) protect the embryo
(2) easily dispersed
(3) introduces a dormant phase into life cycle
pollen grains that are dispersed by wind or a pollinator
male gametophytes
develop within an ovule, enclosed within diploid sporophyte tissue
female gametophyte
plants with “naked seeds”, ovule is exposed on a scale in a cone, all lack flowers and fruits of angiosperms
gymnosperms
pollen grains develop from microspores in male cones by meiosis, female pine cones form on the upper branches of the same tree (female cones are larger and have woody scales), two ovules develop on each scale
gymnosperm reproduction
each ovule contains a ___________ that is surrounded by the integument, one layer becomes the seed coat
megaspore
the ____________ emerges from the pollen grain, it digests its way to the archegonium, delivers its sperm, and then fertilizes
pollen tube
megagametophyte is from the ___________ and the microgametophyte is from the _________
female, male
the largest phylum gymnosperms, include pines, spruces, firs, cedars and others, coastal redwood is tallest tree, bistleconepine is oldest tree
coniferophyta
slow growing gymnosperms of tropical and subtropical regions, sporophytes resemble palm trees, known as cycads
cycadophyta
only gymnosperms with vessels in their xylem, vessels are large tubes for moving water, (drug ephedrine)
gnetophyta
only one living species remains (ginko biloba), dioecious because male and female reproductive structeres from on different trees
ginkgophyta
__________ are the flowering fruit
angiosperms
the bud at the end of a stalk is called the _________
pedicel
the pedicel expands at the tip to form a ______________ to which other parts attach
receptacle
flowering parts are organized in circles called ___________
whorls
outermost whorl
sepal
second whorl
petals
third whorl
stamens
included in the third whorl is the pollen bearing ________ and a stalk called a _________
filament
innermost whorl
carpel
the carpel consists of one or more carpels that house the ___________ gametophyte
female
swollen base containing ovules, later develops into a fruit
ovary
tip
stigma
neck or stalk
style
the female gametophyte has _____ haploid nuclei
8
two of the eight become _________
polar nuclei
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female
pollen production occurs in the _________, dipolid cells undergo meiosis
adfa
___________ is the mechanical transfer of pollen from anther to stigma, pollen grains develop a pollen tube that is guided to the embryo sac
pollination
one of the two pollen grain cells lags behind, this _________ cell divides to produce _____________
generative cells
two sperm cells
as the pollen tube enters the embryo sac, a _________________ occurs, one sperm unites with egg to form the diploid ________, other sperm unites with the two polar nuclei to form the tripolid (3n) ____________ that provides nutrients to the embryo
double fertilization
zygote
endosperm
when the seed germinates, a young ____________ plant emerges
sporophyte
What are the 3 steps of embryogenesis?
(1) storage of food in the cotyledons or endosperm
(2) ovule tissue forms a seed coat
(3) development of carpel wall (ovary) into a fruit
the endosperm varies between plants, nutrients are stored in thick, flesh _________
cotyledons
the integuments develop into a ________, encloses the seed with its dormant embryo and stored food
seed coat
maintain dormancy under unfavorable conditions, protect the young sporophyte, provide food for the embryo until it can produce its own, facilitate the dispersal of the embryo
seeds
one a __________ forms, most of the embryo’s metabolic activities cease
seed coat
___________ cannot take place until water and oxygen reach the embryo, viable for up to thousands of years
germination
seeds don’t germinate until conditions are appropriate, water dependent, wait for passing through intestines, may wait for fires to release ______
seeds
the ovary wall is termed the _________ (has 3 layers), its fate determines the fruit type
pericarp
thin pericarp skin, fleshy inner and middle pericarp, multiple carpels fused, multiple seeds, tomatoes and squash
true berries
carpels with seeds along former style, pericarps flatten to form a dry pod, peas and beans
legumes
during seed formation, adfaksjfskl;j
mature fruiting body
thin pericarp skin, fleshy middle pericarp, one seed surrounded b hard pit made by inner pericarp, includes peach, plum, and cherry
drupe
percarps fuse and dry to form a light “wing”, maple and ash
samara
similar to true berries, many ovaries that are not fused, blackberries and raspberries
aggregate fruits
many flowers form many fruits that fuse together around a stem, each flower produces it’s own three pericarps, ex. pineapple and fig
multiple fruits
the __________ represent the prior sporophyte generation, the _______ represents the next __________
fruit and seed coat
embryo
the fruits and seed coat are from the _______________________
prior sporophyte generation
the developing seed contains remnants of the ________________
gametophyte generation
ingestion and transportation by birds or other vertebrates, hitching a ride with hooked spines on birds and mammals, burial in caches by herbivores, blowing in the wind, and floating in the water helps in ___________
fruit dispersal
