Angiosperms Flashcards
what are flower parts
The Carpels: structures that house ovules
Stamens: have anthers that release pollen
Petals
Sepals
Ovary
Ovules:
where do most flower parts come from
All but the Ovule are modified leaves.
where are eggs found in a flower
eggs are found behind many sporophytic barriers (first type of plant to do this)
what do the stigma and style do
The stigma and style screen pollen, and defend against pathogens
where do you find seed in Angiosperms
The seeds develop with fruit, which is the ovary and its outside wall layers.
what are the micro and megasporangium like in angiosperms
The megasporangium is inside the ovule, and the microsporangium is inside the anthers on the stamen.
The microsporangium produces microspores. Within each microspore a male gametophyte will form.
The microgametophyte is pollen, one of its cells is a tube cell, which upon germination become the pollen tube that will deliver its two gametes into the egg.
how do angiosperms get pollinated
Pollination is mainly wind or animal mediated (including but not limited to insects)
coloured petals and scents attract pollinators
how do angiosperm ovules differ from gymnosperms
The ovule is different from that of gymnosperms:
- it is located inside an ovary
- the megagametophyte (=embryo sac) is reduced to 7 cells
- there are two female gametes (an egg and central cell)
what happens to pollen when it reaches the flower
When pollen lands on the stigma of the carpel, it germinates and the pollen tube pushes first through the stigma.
Then the style and into the ovary, a cavity that houses numerous ovules.
The pollen tube finds an ovule, enters and deposits its two male gametes.
what is double fertilization
One gamete fuses with the egg to form the zygote
the other fuses with the central cell to form the endosperm, a triploid tissue.
This is called double fertilization. The endosperm stores nutrients to feed the developing embryo.
Two-thirds of all calories consumed by humans on this planet are from seed, in particular endosperm.
Seed makes us possible.
why are seeds important for humans
Two-thirds of all calories consumed by humans on this planet are from seed, in particular endosperm.
Seed makes us possible.
what up with coco del mar
The endosperm in the seed of the palm Coco del Mar (which is the largest seed in the world), can be pretty significant.
It allows an embryo to survive for months while floating around the Indian Ocean. The seed will land on beaches and germinate.
how do photosynthesized affect the atmosphere
Plants produce oxygen during the day, and release carbon dioxide during the night
Over the course of life on earth, different groups like Cyanobacteria, Red alga, and plants evolved, and starting spewing Oxygen into the atmosphere, raising its level to 21% in earths atmosphere
How did flowers help angiosperms
the advent of flowers helped angiosperms exploded and take over the world, exploding in diversity between 126-65 mya
what is the difference, between petals, sepals, and tepals
- the petals and sepals are similar, but different in colour and form. (sepals are the green petal looking things in many flowers)
- if they are the same colour, petals and sepals are called Tepals
how can angiosperm species and their pollinators be closely entwined
- Some flowers have evolved specific shapes to accommodate particular pollinators, such as long tubular flowers for hummingbirds
- The co-evolution of flowers and their pollinators has led to intricate relationships and specialized adaptations
what is Hydnora africana
- Jackal food
- Some flowers have evolved specific shapes to accommodate particular pollinators, such as long tubular flowers for hummingbirds
- The co-evolution of flowers and their pollinators has led to intricate relationships and specialized adaptations
what’s up with Orchids
- lots of them (25,000+ species)
- really big petal called the labellum
- attracts insects
- insects fall in, the only exit is at the back of the labellum where the pollen is
- many groups of people organized around orchids (600+ orchid societies)
How did angiosperms take over
- halved their absolute genome size (compared to gymnosperms) promoting a higher mutation rate.
- Less DNA per cell allowed smaller cells, which meant more cells per leaf, including stomata per leaf. This led to better gas exchange and therefore better photosynthesis
- they reproduced more efficiently, taking less time then gymnosperms
- corn takes 7 hours, pine takes 15 months (pollination to fertilization)
what is Enhalus acoroides
Enhalus acoroides, eel grass or tape seagrass, grows on Iriomote Island, one of the southernmost islands of Okinawa, Japan.
Due to lowest tides being when there is a full moon, and especially in the full moon in July when this plant is flowering. The abiotic evets of tide and wind contribute to the only sea surface pollination mechanism known from any plant in the world.
how does Enhalus acoroides reproduce
Tide go up, males release flowers which rise to surface in air bubbles.
Tide goes down
Female flowers eat males
Female plant buries fruit in soil (called negative geotropism, growing against gravity)
what does inflorescence mean
A bunch of flowers on one stem
