Exam 2 (lect 9,11)

Question 1

angiosperm time

Answer 1

200-250 million years ago

sudden appearance of abundant/diverse in Cretaceous period

Question 2

competitive exclusion hypothesis

Answer 2

why angiosperms exploded so quickly?

exploited more niches and compete with gymnosperms (only adapted to some enviros)

Question 3

2 hypotheses for gymnosperm to angiosperm

Answer 3

1. Anthophyte

2. Gnepine

Question 4

anthophyte hypothesis

Answer 4

morphological data
gymnosperms NOT monophyletic group but para
Gnetophytes are most closely allied (no archegonia, pollen tube, xylem vessels)

Question 5

gnepine hypothesis

Answer 5

DNA seq data
angio and gymno are both monophyletic groups
gnetophytes are most closely related to Pines)
no extant close relatives to angiosperms
convergent evol

Question 6

oldest angiosperm lineage

Answer 6

amborella trichopoda

Question 7

4 basal groups of angiosperm lineages

Answer 7

1. amborella trichopoda
2. nymphaeceae (water lilies + relatives)
3. austrobaileyales (star anise + relatives)
4. Mangoliidae (magnolias + relatives)

Question 8

star anise

Answer 8

basal angiosperm
austrobaileyales
spice (chinese cooking)
Pho
shikimic acid is precursor for tamiflu (antiviral for influenza)

Question 9

monocots diff from dicots

Answer 9

one cotyledon (seedling after germ)
parallel leaf venation (grasses)

Question 10

dicots diff from monocots

Answer 10

two cotyledons

netlike leaf venation

Question 11

dicots phyletic group

Answer 11

para b/c basal and then eudicots

Question 12

monocots phyletic group?

Answer 12

monophyletic

Question 13

monocot v dicot diversity

Answer 13

mono ~90,000 species

eudictos ~200,000

Question 14

monocot species ex

Answer 14

bamboos, birds of paradise, onions, grasses, frilium, orchids

Question 15

inconspicuous flowers

Answer 15

1. grasses and other wind pollinated (reduced)
2. showy parts can be leaves and not petals (poinsettas w flowers in middle)
3. catkins of trees (windpollination, small bunches)
4. self fert species (weeds, don’t need to attract pollinator)

Question 16

anther in life cycle

Answer 16

hold microsporocytes aka microspore mother cells
4 microsporangia in 2 pairs
split at junction when mature, spread pollen
microspore mother cells (2n) divide via meiosis to form tetrads of haploid pollen grains

Question 17

ovary in angio life cycle

Answer 17

change

holds ovules, fleshy part

Question 18

microsporangia in gymno v angio

Answer 18

gymno - borne in cones or stobili

angio - borne in flowers (anthers)

Question 19

angiosperm pollen

Answer 19

3 cells! super reduced male gametophyte
gymno pollen had 5 cells
has tube cell and generative cell

Question 20

megagametophyte angiosperm

Answer 20

heterosporous
4 megaspores with 3 degenerating
divides 3 times resulting in cell with 8 nuclei
cell walls form 7 cells
one cell has 2 nuclei (polar nuceli, binucleate)
NO archegonia

Question 21

cell walls of female gametophyte angio

Answer 21

form 7 cells, 3 at the walls
3 antipodals
2 synergids (same end as micropyle, between is the egg cell)

Question 22

fertiliz angio

Answer 22

after pollination, pollen germ and mature male gametophye grows to female gametophye
pollen tube grows through papilla on stigma on the style

Question 23

pollen tube

Answer 23

tube nucleus controls growth
coils around ovule to reach micropyle
only living cells on the growing end

Question 24

synergids

Answer 24

2 cells in the megagametophyte
secrete to direct pollen tube and rupture of pollen tube to release sperm
surround egg cell
on side with micropyle

Question 25

double fertiliz

Answer 25

1. one sperm nucleus fuses with egg (dip zygote) | 2. other sperm nuc fuses with the 2 polar nuclei (triploid)

Question 26

double fertiliz in gnetophyte

Answer 26

common in some but a bit different ephedra supports sister theory anthophyte hypothesis

Question 27

ovule develop

Answer 27

into seed zygote to embryo (2n) = new sporophyte embryonic leaves, cotyledon, primary root

Question 28

ovary develop

Answer 28

sperm + 2 polar nuclei --> endosperm (3n) = nutrient tissue | fruit! seed coat

Question 29

darwin abominable mystery

Answer 29

sudden rapid diversification of flowering plants | there is a long unrecorded history of angiosperms prior to creetaceous (not in fossil record)

Question 30

new caledonia

Answer 30

island off the coast of australia basal angiosperm (amborella trichopoda) possible diversification here with no clear fossil record

Question 31

rapid diversific due to pollinator

Answer 31

gaston de saporta relationship with insect explosion of pollinator and flowering at same time co-radiation/co-diversification

Question 32

flowers of basal angiosperms

Answer 32

radially symmetric white or red/maroon pollinators receive pollen as reward, rarely nectar (bees feed pollen to offspring) petals/sepal indistinguishable

Question 33

pollinator of basal angio

Answer 33

insect pollin occured early (ya happening in gymno) diptera/flies first beetle pollination

Question 34

pollinator deceit

Answer 34

trick pollinators to come heat attract pollinator to lay eggs mimic insect to 'mate'

Question 35

cretaceous flower in fossil record

Answer 35

NJ, 90 mya fossil similar to water lily (nymphaeaeceae) beetle pollination involves insect entrapment

Question 36

water lily pollination

Answer 36

2 openings 1. female, beetles with pollen come and get trapped 2. cover with male pollen and send off to pollinate other flowers

Question 37

bat pollination syndrome

Answer 37

night, dull white or green strong, fermented odors ample nectar reward (larger animal) desert SW, tropics

Question 38

bee pollination syndrome

Answer 38

day, Yellow, blue, purple, UV patterns light, sweet scent pollen and nectar reward

Question 39

coevolution btwn plants and pollinator

Answer 39

possible explanation of rapid angiosperm diversific

Question 40

darwin's orchid

Answer 40

gradual increase in nectar spur length due to ongoing coevol with same pollinator. 1:1 interaction insect with hella long tounge

Question 41

pollinator shifts

Answer 41

other theory of rapid angiosperm diversific more often animals are not a ubiquitous distrib in part of species range, one pollinator becomes predominant and rapid evol for selection of the pollinator punctuated change due to pollination shift

Question 42

columbine genus (aquilegia)

Answer 42

nectar spurs. tested pollinator hypoth pollination syndromes related to floral traits nearly non-overlapping distrib of spur lengths among pollination syndromes bee, humming bird, hawkmoth

Question 43

hummingbird intermediate

Answer 43

between bee to hawkmoth eurasia cannot jump to optimal size for hawkmoth bird necesary!!

Question 44

pollinator limitation

Answer 44

shift reproductive strategy wind pollination selfing switch to new pollinator

Question 45

wind pollination syndrome

Answer 45

lots of flowers, many pollen grains, unisexual flowers (don't have both parts), open habitats (before leaves on trees) ragweed, oak, bamboo

Question 46

self-pollination evol

Answer 46

``` from outcrossing do not separate by time (dichogamy) 1. colonizing species ('weedy') 2. marginal habitats (edge of range, fewer plants and pollinators) 3. annual life history (one shot) arabidopsis thaliana ```