Transcript Asplenium marinum tiny newborns. At this stage of its development

Plant Reproduction
More interesting than you thought
Seedless plants
Spore = A reproductive cell that develops
into an individual without union with other
cells.
Alternate between diploid and haploid
generations.
Male and female parts.
Haploid cells can function as an individual!
One of the first types of plants, they have
been around for a very long time.
Examples
 Asplenium marinum tiny newborns.
At this stage of its development are
a single frond green heart-shaped
Horsetail
Gymnosperms
“Naked seed” because they are not
covered by fruit thus no flowers
Separate diploid male and female parts
produce haploid sperm and eggs (like us).
Male cones only live for a few weeks.
Female cones can live for years.
Most of these are pollinated by wind.
Examples: pine, firs, cypresses, redwoods
Male cones and mature females cones
Pollination
 Because plants can’t go find a mate they require
the help of:
Pollination by wind, water or gravity, OR
Pollination by animals like, insects, birds, small
mammals, bats, etc.
 But the plant must supply something:
Some kind of reward such as food (nectar)
Some way to advertise such as odor, color, shape,
texture.
A way to get the pollen on the visitor but also a way to
transfer it to the next flower.
Wind pollination
 Flowers are usually unscented.
 Have either very reduced petals and sepals or
lack them altogether.
 Do not produce nectar.
 Male and female reproductive structures are
commonly found in separate plants.
 The male plants have numerous exposed
stamens, often on long filaments;
 The female flowers have long, often branched,
feathery stigmas.
Why?
 If you are not trying to
attract a pollinator,
you do not need to
advertise.
 It saves on energy.
 Negative – you need
to release A LOT of
pollen – part of the
reason so many
people have allergies.
Weeping willow
Pollination by Bats
 Over 300 species of fruit depend on bats for
pollination.
Mangoes, bananas, guavas
 Flowers visited by bats usually
Open at night
Large in size (1 – 3.5 inches)
Pale or white in color
Very fragrant
Copious dilute nectar
 They also feed on the insects in the flowers
Fun Fact
Plants have evolved different flowering
seasons
This means there is decreased
competition for pollinators
February = skunk cabbage
March & May = red columbine
August – Sept = cardinal flower
Partnerships
The yucca plant and yucca moths are so
interdependent that they can not live
without each other.
The female moth pollinates the plant and
then lays her eggs in the ovary.
She can smell if another female has
already laid eggs in an ovary.
Some of the seeds will help feed the
larvae.
Yucca
Pollination by Deception - Orchids
 Food Deception
Falsely advertise the
presence of food by
bright colors and sweet
scent.
Reproduction Deception
 Some orchids have co-evolved to be pollinated
by one specific type of insect
 The male “thinks” he is mating with a female
because the plant looks so much like the female
insect.
 The plant wins because pollination occurred.
The Corpse Flower?
 Rafflesia
The largest single
flower by weight.
It is a parasite.
 Titan Arum
The largest unbranched
inflorescence.
Carnivorous Plants
 There are 600 species
 They lure prey, catch prey, kill prey and then
digest and absorb the nutrients.
 This is NOT a method of pollination.
Pollination by entrapment
Sources
www.fs.fed.us/wildflowers/pollinators/index
.shtml
Botanical Society of America
www.anu.edu.au/BoZo/orchid_pollination
Botany.cz
 http://mundani-garden.blogspot.com/2010/12/sealover.html
Why is Meiosis Important?
It is important because it produces egg &
sperm cells (sex cells) which are haploids.
Since it makes haploid cells each new
generation starts off with the same number
of chromosomes as the parent.
Cell Divisions
How many cell divisions does mitosis go
through?
Only one, because it is making diploids.
How many cell divisions does meiosis go
through?
Two, so it can make a haploid cell.
What are the advantages &
disadvantages of sexual reproduction
 Advantage:
Genetic variation helps
a species survive
changing environment.
 Disadvantages:
Need time to grow
before they can
reproduce.
Requires energy to get
eggs and sperm
together.
Requires energy to
make egg & sperm.