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Chapter 10: Flowers and Reproduction - Coggle Diagram
Chapter 10: Flowers and Reproduction
Sexual Reproduction
The Plant Life Cycle
spores
no syngamy
can undergo mitosis
do not produce diploid plant
produces haploid plant
grow into new haploid plant
known as gametophyte
gamete
syngamy/fertilization
gametes fuse with other gametes
produces diploid zygote
does not undergo syngamy
it will die
cannot live alone
cannot grow into haploid individual
Gametes
sperm
males
meiosis
haploid sex cells
egg
females
meiosis
sperm + egg
zygote
becomes new diploid individual
Sporophyte Phase (sporophyte generation)
critical factor
sporophytes are always diploid
organs w/ cells
capable of meiosis
results in haploid spores
only in plants
in animals (haploid gametes)
Mammalian Gametes
two types
megagametes
megaspores
only 1 produced in life cycle
cannot swim
large eggs
meggametophytes
produce females
oogamous mammals
microgametes
microspores
only one produced in life cycle
small sperm
able to swim
microgametophytes
produce males
oogamous mammals
Flower Structure
four types of floral appendages
sepals
petals
stamens
carpels
complete flower
flower contains all 4
incomplete flower
lack 1 or more of appendages
sepals
lowermost/outermost of the 4 appendages
modified leaves
enclose other flower parts as they mature
typically the toughest, waxiest part of flower
protect flower buds
fend off bacteria/fungal spores
high humidity maintained inside bud
deters insects
petals
attract correct pollinators
perianth
sepals + petals
above sepal on receptacle
corolla
petals together
leaf like
broad
flat
thin
different from leaves
thinner than leaves
a more delicate structure
contains multiple pigments other than chlorophyll
few or no fibers
stamens
above petals
androecium
"male" part of flower
technically not male because spores are produced instead of gametes
produces pollen
made of two parts
filament
stalk
anther
when pollen is produced
diploid cells
each one is 4 long columns
distinct
meiosis
carpels
located at highest part of receptacle
3 main parts
stigma
catches pollen grains
style
elevates stigma to useful position
ovary
where megaspores are produced
Gemetophytes
microgametophytes
located in pollen cell wall
large vegetative cell
small generative cells
forms 2 sperm cells
pollen tube
germinates pollen grain on stigma
penetrates loose, open tissue
absorbs nutrients from stigma
downward growth through style into ovary
megagametophytes
embryo sac
multi-nucleated megagametophyte
nuclei migrate through cytoplasm (pulled by microtubules)
2 at center, 3 at ends
Fertilization
syngamy of sperm & egg
plasmogamy
fusion of protoplast of gametes
karyogamy
fusion of nuclei
endosperm nucleus
2nd sperm nucleus released from pollen tube
migrates from synergy to central cell
undergoes karyogamy
both polar nuclei
establishes large endosperm nucleus
triploid
3 sets of genes
double fertilization
one sperm fertilizes egg
forms zygote
other sperm fertilizes polar nuclei
forms primary endosperm nucleus
extraordinarily active
rapid division (mitosis)
cell cycle lasts a few hours
Embryo & Seed Development
suspensor
usually delicate
ephemeral in angiosperms
not easily detectable in mature seed
pushes embryo deep into endosperm
coyledons
embryos of seed plants
leaf like structure
involved in nutrient transfer from endosperm
nutrient storage
embryo is an elongated cylinder
epicotyl
embryonic stem
radicle
embryonic root
hypocotyl
root/shoot junction
Fruit Development
fruit
mature ovule
three distinct layers during growth
exocarp
outer layer
skin/peel
mesocarp
middle layer
flesh
endocarp
innermost layer
pit of cherry
thin
may be tough
pericarp
fruit wall
thickness varies with fruit type
Flower Structure & Cross-pollination
cross pollination
self-pollination
same flower/same plant
pollination of carpel by pollen
all genes come from same parent
pollination of carpel
pollen of different individual
sperm & egg cells from different plants
new combo of genes
may be better adapted than parents
evolution favors cross-pollination
genetic diversity
better adaptations
stamen and style maturation times
self fertilization
not effective
anthers and stigmas mature at different times
stamens/carpel can't form
stamen and carpel develop
only if anthers/stigmas mature at same time
pollen from cross-pollination
stigma and pollen incompatibility
compatibility barriers
chemical reaction between pollen and carpels
prevent pollen growth
occurs in self pollination
one compatible system
pollen tube grows
stigma and style test proteins on surface
if one protein is produced by incompatible gene
style and stigma both block pollen growth
self-pollination
plant can't self pollinate
pollen tube genes match
style/stigma blocking occurs
monoecious & dioecious species
non-essential organs
no spore production
may be sepals or petals
lack stamen/carpels
two types of flowers
perfect flower
contains both essential/non-essential organs
could lack sepals/petals (or both)
no spore production
considered non-essential organs
imperfect flower
lacks either essential or non-essential organs (or both)
incomplete flowers
essential organs
produce important spores
if lacking, sexual reproduction is affected
monoecious
condition of having staminate flowers
corn, cat tails
located on same plant
dioecious
dioecy
produce only staminate flowers
located on different plant
marijuana
dates
willows
animal pollinated flowers
zygomorphic
insects
bats
birds
bilaterally symmetrical
one longitudinal plane
two halves (mirror images)
coevolution
occurs between birds/flowers
flower becomes adapted for visitation
actinomorphic
known as regular
radially symmetrical
any longitudinal cut through the middle
produces mirror images
wind pollinated flowers
distinct set of modification
large feathery stigma
good at catching pollen
increases surface area
ovaries do not need special protection
flower may be very small
mutation to prevent petals
saved energy
can be used in other areas of flower
sepals reduced or absent
grasses
hickories
oaks
all conifers
grow in dense populations
range lands or forests
ovary position
define position
half-inferior ovary
other parts are perigynous
appear attached to side
sepals, stamens, petals
intermediate/partially buried ovaries
inferior ovary
parts are epigynous
ovary under other parts
can result if receptacle tissue grows upward around ovary
superior ovary
parts are hypogynous
ovary above other parts
most common arrangment
no fusion occurs
Fruit Types & Seed Dispersal
true fruits & accessory fruits
multiple fruits
type of compound fruit
figs
mulberries
pineapple
formed by crowding together
simple fruits
develops from single carpel/ovary or fused carpels of single flower
most common type of fruit
true fruits
contain only ovarian tissue
develops only from carpel tissue
accessory fruits
called false fruit if non-ovarian tissue is present
aggregate fruit
develops from crowding together
carpels
type of compound fruit
raspberries
classification of fruit types
dry fruits
not typically eaten
dehiscent fruits
break open/release seeds
develop from compound gynoecium
schizocarp
mericarps
compound ovary that breaks
capsule
opens many different ways
splitting along lines of fusion
splitting between lines of fusion
splitting into top/bottom
opening by small pores
developing from single carpel
legume
peas
fruit breaks open along both sides
follicle
fruit breaks open along one side
milkweeds
indehiscent fruits
do not break open/release seeds
developing from a single carpel
caryopsis
occurs during maturation
simple/small contains one seed
achene
similar to caryopsis
seed/fruit remain distinct
fruit wall thin and papery
samara
one-seeded fruit
winglike outgrowths of ovary wall
maple
ash
alder
developing from a compound gynoecium
nut
pericarp hard at maturity
all but one ovule degenerate during development
walnut
fleshy fruits
usually eaten by animals
berry
fleshy fruit with all 3 layers
soft
contain endocarp, mesocarp, and exocarp
pome
similar to berry
endocarp is papery/leathery
apple
drupe
similar to berry
sclerenchymatous
endocarp is hard
cherry or peach
pepo
exocarp is tough
pumpkins
hard rind
inner soft tissue
may not be differentiated into 2 distinct layers
hesperidium
exocarp is leathery
citrus
Inflorescences and Pollination
inflorescences
collective visual sign to pollinator
discrete group of flowers
two basic arrangements
determinate inflorescences
limited growth potential
due to apex being converted to flower
terminal flower usually opens first
lower ones open afterwards succesively
simplest type
bract
with axillary flower
below terminal flower
indeterminate inflorescences
lowermost/outermost open first
new flowers initiated
raceme
major inflorescence axis
flowers born on pedicels
all are about same length
catkins
flowers imperfect
staminate
carpellate
almost always small, wind pollinated
spadix
spike-like inflorescence
with imperfect flowers
both types occur
main axis thick/fleshy
minute flowers embedded
subtended or enclosed by bract
called a spathe
panicle
branched raceme
several flowers per branch
spike
flowers are sessile
lack a pedicel
similar to raceme
Concepts
2 functions of reproduction
producing offspring with identical genetics
creating new individuals with different genetics
asexually reproduced plants
can quickly replicate
usually not long-distance dispersed
seeds
produced by sexual reproduction
often have long distance dispersal
may be widely dispersed
germinate in numerous diverse sites
Asexual Reproduction
fragmentation
individual becomes self sufficient
if middle plant dies
act as individuals
ends become separated
establishing adventitious roots
large spreading/vining plants
grows to several meters long
modifications
cacti
branches poorly attached
break off easily
parts form roots
becomes independent
saxifrage, pineapple trees, grass
plantlets are formed
small bulbs
bulbils
where flowers would be expected
willows and thistles
adventitious shoot buds
forms on roots
grow into plants
adventitious buds
may grow out even if parent is still alive
small clusters of trees
may consist of single individual
