Unit 4 - Chapter 32.3 Angiosperms

Question 1

Are flowers gametophyte structures or sporophyte structures?

Answer 1

Sporophyte

Question 2

Anthophyta (synapomorphies?)

Answer 2

The one division of angiosperms! flowering, fruiting plants!
-Last diverging division of plants
-COMPLEX vascular tissues: xylem with tracheids AND vessels, efficient transport.
-Broad leaves
-Abscission (leaves fall off
-Flowers
-Fruit
-3n endosperm develops after fertilization

Question 3

Darwin’s “Abominable Mystery”

Answer 3

WHAT IS THE ORIGIN OF FLOWERING PLANTS???
…Cretacious pd. ~135MYA pollen/fossils of angiosperms found
~190MYA Molecular clock leads us to think angiosperms may have evolved around this time?

Question 4

Fruits

Answer 4

Synapomorphy of angiosperms: protect seeds

Question 5

Double Fetilization

Answer 5

Two sperm cells enter ovary. One fuses w egg, other fuses with polar nuclei to form triploid endosperm

Question 6

Angiosperm vs Gymnosperm endosperm

Answer 6

-Gymnosperms form endosperm whether or not the eggs are fertilized
-Angiosperms form endosperm when eggs are fertilized (via double fertilization

Question 7

Flower Anatomy (perianth, filament, anther, ovule, style, stigma

Answer 7

-Perianth (“sepals” look like small leaves; and petals)
-Stamen (“Filament” stems; “anther” heads. male reproductive parts)
-Carpel (Ovary, “Style” stem; “Stigma” heads where pollen grains land)

Question 8

Calyx

Answer 8

All sepals collectively are referred to as the Calyx.

Question 9

How does sperm reach flower eggs?

Answer 9

-Lands on stigma, burrows down through style until it makes its way into the ovary

Question 10

Angiosperm life cycle

Answer 10

-Pollen grains leave anther and land on stigma, each sends down two sperm through the style and into the ovules
-Both sperm enter an ovule. One fuses with an egg to form a zygote, the other fuses with two haploid “polar nuclei” to form the triploid endosperm
-OVULE MATURES INTO THE SEED !!!

Question 11

Plant Importance to humans!

Answer 11

-Edible
-medicine
-wood, fibers, fuels

Question 12

Hypothetical EVOLUTIONARY origin of Carpels

Answer 12

-Leaflike structures that fold slightly over ovules
-Folds fully into a cylinder shape closed by sticky secretions
-Cylinder seals into a fully closed off tube
-Parts of this sealed tube differentiate into ovary, style, and stigma. This is now a pistil composed of one carpel, eventually multiple carpels will fuse into compound pistils

Question 13

Sepal

Answer 13

Leaf-like structures that protect the flower in bud, and support it in bloom

Question 14

Hypothetical EVOLUTIONARY origin of stamens

Answer 14

-Leaflike structure with microsporangia
-Structure becomes narrower
-Microsporangia cluster to the tip of the leafish structure (becoming the anther), leafish part becomes the filament (stem-ish structure) of the stamen.

Question 15

Amborella

Answer 15

-Earliest diverging angiosperms!
NO vessels; dioecious; many unfused parts

Question 16

Water Lillies; Star Anise; Magnoliids

Answer 16

2nd, 3rd, and 4th diverging.
Evolutionary trend of structures fusing; and # of sepals, petals, etc decreasing

Question 17

Monocots

Answer 17

“One Cotyledon”
-scattered vascular bundles
-Parallel veins
-Linear leaves
-herbs
-grains!

Question 18

Cotyledon

Answer 18

First leaf that emerges from a seed

Question 19

Scattered vascular bundle

Answer 19

Trait of monocots. Bundles of xylem and phloem are not uniform in the plant

Question 20

Eudicot

Answer 20

Two cotyledons
-Vascular bundles in a ring
-net venation (netlike branching veins)

Question 21

Pollination… examples of driving forces

Answer 21

-insects
-birds
-mammals
-herps
-elements (wind, water)
-self-pollination

Question 22

Two major types of pollination

Answer 22

-Selfing (within the same flower/plant)
-Outcrossing (between two plants)

Question 23

Pollination Co-evolution

Answer 23

-Flower evolves a specific shape, then an animal evolves morphology to better grab nectar, pollen, lipids, fragrances