Evolution and Biogeography of Australian Flora

Question 1

plants arose from

Answer 1

an algae like ancestor

Question 2

bryophytes

Answer 2

earliest branching, oldest plants

• liverworts, mosses, hornworts
• use spores not seeds
• lack vascular tissue (small)

Question 3

pteridophyte

Answer 3

oldest vascular plants

• lycophytes, ferns and horsetails
• use spores but height helps with dispersal

Question 4

gymnosperms

Answer 4

oldest seed producing plants (naked seeds)

• pines, conifers
• pollen and seeds by cones (sexual organs)

Question 5

angiosperms

Answer 5

most recent and common (enclosed seeds)

• 90% land plants
• flowers and fruit aid pollenation
• sexual selection

Question 6

why are there similar species in southern areas?

Answer 6

past connections and continental drift

Question 7

australia in Gondwana

Answer 7

• cretaceous and cenozoic: Australia was part of Gondwana (NZ, South America, Africa etc.)
• Australia left Antarctica 30 mill yr ago
• isolation and evolution

Question 8

eucalypts facts

Answer 8

75% of biomass

700 species, most endemic to Australia

Question 9

break up of Gondwana and eucalypts

Answer 9

160mya

• Australia, Antarctica, South America and NZ were connected
• eucalyptus ancestors in wet rainforests
• eucalyptus pollen 100-66mya (cretaceous)
• monsoonal (not many fossils) climate, volcanic activity and bushfires - oils make fires easy to start but hard to maintain

Question 10

where did eucalyptus go in NZ, South America etc.

Answer 10

• need fire to regenerate
• wet conditions = fungi, bacteria, disease
• too wet in NZ

Question 11

arrival of humans

Answer 11

arrived 50 000 years ago from Indonesia and china
charcoal evidence suggests earlier
extinctions

Question 12

terrestrial environments

Answer 12

tropical, subtropical, temperate, warm temperate

• great divide - wetter on the East (rainforests) and frier on the west (dry woodland)
• deserts in central australia

Question 13

El Nino - Southern Oscillation

Answer 13

2-3 year cycle
usually warm aid goes west to east (cools and descends) high pressure zone
air in the east warms during EN and low pressure in east - drought and bushfire

Question 14

la nina

Answer 14

above average rainfall and flooding

Question 15

el nino and la niña are enhanced by

Answer 15

climate change

Question 16

marine environments

Answer 16

pacific, southern and Indian oceans

latitude and structure of continental shelf affects environments

Question 17

relic and major components of Australian flora

Answer 17

relic live in moist, rainforests

major has adapted to arid conditions

Question 18

dominance of hard leaves

Answer 18

sclerophylls

• survive with low nutrients, water stress and fires
• short leaves, thick cuticle and sunken stomata

Question 19

succulents

Answer 19

• store water in leaves and stems
• xerophytes (live in dry conditions)
• sunken stomata

Question 20

myrtaceae

Answer 20

eucalyptus family. 4-5 perianth parts and numerous stamens

Question 21

proteaceae

Answer 21

banks family - 4 lobed perianth, 4 stamen

Question 22

ericaceae

Answer 22

heath family - stiff leaves and tube like flowers, infertile soils

Question 23

mimosaceae

Answer 23

wattles - 1000 species, increase nitrogen content of soils

Question 24

fabaceae

Answer 24

pea family

Question 25

asteraceae

Answer 25

daisy family

Question 26

orchidaceae

Answer 26

orchids

Question 27

northern plants

Answer 27

migration of plants from elsewhere into the north | seeds in tufts or hairs disperse

Question 28

how to flowers spread pollen

Answer 28

attracting animals to flowers and fruit

Question 29

stamen

Answer 29

male reproductive parts filament: holds anther away from flower for pollinators to access anther: contains pollen grains (each has two sperm cells)

Question 30

sepal

Answer 30

modified leaves that surround the bud. make up perianth that envelops the reproductive parts

Question 31

petals

Answer 31

modified leaves that also make up perianth | - colours attract pollinators

Question 32

pistil

Answer 32

female reproductive part. pollen lands on the sigma and germinates, sending a pollen tube containing sperm down the style. pollen tube delivers sperm to the ovary (egg in an ovule)

Question 33

inflorescence

Answer 33

arrangement of flowers like with banksia can support birds lots of nectar

Question 34

indigenous use of plants

Answer 34

``` medicine insect repellent dye transport fire have multiple uses ```