Angiosperms

Question 1

what are flower parts

Answer 1

The Carpels: structures that house ovules

Stamens: have anthers that release pollen

Petals

Sepals

Ovary

Ovules:

Question 2

where do most flower parts come from

Answer 2

All but the Ovule are modified leaves.

Question 3

where are eggs found in a flower

Answer 3

eggs are found behind many sporophytic barriers (first type of plant to do this)

Question 4

what do the stigma and style do

Answer 4

The stigma and style screen pollen, and defend against pathogens

Question 5

where do you find seed in Angiosperms

Answer 5

The seeds develop with fruit, which is the ovary and its outside wall layers.

Question 6

what are the micro and megasporangium like in angiosperms

Answer 6

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.

Question 7

how do angiosperms get pollinated

Answer 7

Pollination is mainly wind or animal mediated (including but not limited to insects)

coloured petals and scents attract pollinators

Question 8

how do angiosperm ovules differ from gymnosperms

Answer 8

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)

Question 9

what happens to pollen when it reaches the flower

Answer 9

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.

Question 10

what is double fertilization

Answer 10

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.

Question 11

why are seeds important for humans

Answer 11

Two-thirds of all calories consumed by humans on this planet are from seed, in particular endosperm.

Seed makes us possible.

Question 12

what up with coco del mar

Answer 12

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.

Question 13

how do photosynthesized affect the atmosphere

Answer 13

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

Question 14

How did flowers help angiosperms

Answer 14

the advent of flowers helped angiosperms exploded and take over the world, exploding in diversity between 126-65 mya

Question 15

what is the difference, between petals, sepals, and tepals

Answer 15

• 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

Question 16

how can angiosperm species and their pollinators be closely entwined

Answer 16

• 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

Question 17

what is Hydnora africana

Answer 17

• 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

Question 18

what’s up with Orchids

Answer 18

• 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)

Question 19

How did angiosperms take over

Answer 19

• 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)

Question 20

what is Enhalus acoroides

Answer 20

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.

Question 21

how does Enhalus acoroides reproduce

Answer 21

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)

Question 22

what does inflorescence mean

Answer 22

A bunch of flowers on one stem