L2 Time Flashcards
what is the name for the current geological time period and when did it begin
holocene, 11,700 years ago
how long ago was the extinction of dinosaurs
65 million years ago
in what geological time period was the extinction of the dinosaurs
cretaceous
what is missing in non-vascular plants
xylem and phloem
what is the benefit of a vascular system
allows plants to grow taller
what were the first plants
charophytes - a group of green algae
what developed after charophytes
bryophytes
what developed after bryophytes
early vascular plants - seedless
ferns and horsetails
what were the first seed plants
gymnosperms - conifers and pines
what is the evolution and diversification of angiosperms often referred to as
the radiation of flowering plants
when was the precambrian period
650 million years ago
when were the earliest forms of plant life found and what were they
precambrian (650 MYA) - algae
how was land mass arranged in the precambrian period
into a supercontinent = Rodinia
when were the Cambrian and Ordovician periods and what plant form was present
540-440 million years ago
aquatic life dominated by algae
what followed the Ordovician period and when was it
Silurian period
440-410 million years ago
what key event occured in the Silurian period for plants
soil developement led to movememnt out of water
what is the name for the extinct group of primitive land plants
Cooksonia
does the Cooksonia have vascular tissue
yes, is the oldest known plant to have a stem with vascular tissue
what were Cooksonia a transition between
primitive non-vascular bryophytes and vascular plants
where are most of the type specimens of Cooksonia found
UK
what ways did a plant need to adapt in order to survive on land
surface to prevent drying out
pores for gas exchange and water regulation
vascular system to distribute water, minerals and food
support to give structure to plant body + grow taller
anchoring system
fertilisation without aqueous environment
what surface do plants have to prevent drying out
thick and waxy cuticle
pores for gas exchange and regulation of water loss =
stomata
vascular system to distribute water, minerals anfd food =
xylem and phloem
support to give structure to the plant body andn allows them to grow taller =
vascular tissue and lignin
anchoring system =
roots
accomplish fertilisation without aqueous environment =
pollen (wind or insect dispersal)
what is the purpose of having a formant embryo
ability to wait for suitable environmental conditions before sprouting
when were the first forests and what geological time periods were they found
Devonian and Carboniferous
395-286 million years ago
when did gymnosperms develop
Devonian and Carboniferous
what was the structure of land masses in the Devonian and Carboniferous periods
supercontinent Pangea
what changes occured in the global climate in the Devonian and Carboniferous periods
changed from warm, humid and ice-free to cooler, drier climates with extensive glaciation
where was the extensive glaciation found
high latitudes of Southern hemisphere
what is the scientific name for the ‘scale tree’
Lepidodendron
what are the Lepidodendron
axtinct genus of primitive tree
what are Lepidodendrons related to
clubmosses (seedless vascular plants)
what genus do present day ‘clubmosses’ belong to and are they true mosses
Lycopodium
not really a moss as it has a vascular system
what are the Calamites
an extinct genus od arborescent (trees) horsetails
when were Carboniferous swamp forests present and what did they result in
350-300 million years ago
resulting in coal formation
what caused a drop in carbon dioxide in the carboniferous period
CO2 removed by plant growth and limestone rock formation
carbon not released by decaying plants (did not have time to fully decay)
when was the evolution of gymnosperms
early Carboniferous period ~ 360 million years ago
when was the upper Permian period
~ 260 million years ago
what proprtion of global flora was gymnosperms in the Upper Permian period
60%
what does it mean to say that gymnosperms have ‘naked seeds’
their seeds are not enclosed in an ovule
do gymnopserms have flowers or fruits
neither
4 groups of extant gymnopserms
conifers,
cyads,
Ginko biobla,
Gnetales
what is the general structure of a cyad
palm like leaves with large cone
where is Ginko biloba found
only found in China
what are the three genuses of Gnetales
Ephedra
Gnetum
Welwitschia
where are Ephedra found
arid areas
where are Gnetum found
tropical evergreens
what is the single extant species od Weleitschia and where is it found
Welwitschia mirabilis
endemic to Namib desert of Namiba and Angola
when did the first flowering plants appear and what geological time period was this
~ 140 million years ago
in the Cretaceous period
by which point had angiosperms become globally dominant
early Tertiary - 65 million years ago
where did the earliest angiosperms develop
near the equator = palaeotropics
how long after after the first vascular plants did angiosperms appear
300 million years later
what group do grasses belong to
angiosperms
what occured during the Eocene Epoch
appearance of grasses
how many species of grasses are there
10,000
what role to grasses play in the human diets
provide 52% of the carbohydrates
how has India moved through time and what did this form
moved from SOuthern to northern hemisphere forming the himalayas
how do clouds interact with a mountain
clouds drop rain on the side of the mountain they approach first leaving the other side to become arid
how are plants classified into biomes
according to structural character of vegetation (physiognomy)
what was the climate in the early carboniferous period
narroe tropical everwet (China, Scandinacia, Greenland, N America)
higher palaeolatitudes had warm temperature
ice in the South
what was the climate in the Permian period and what plants radiated
radiation of gymnosperms
increasing global warmth and aridity
no ice
what was the climate in the Eocene period and what plamts were present
all floras dominated by woody plants
land area is almost completely forested, no ice and little desert
tropical everwet, evergreen angiosperms with large leves (modern tropical forests)
when was the Eocene
during the Tertiary period
55-34 million years ago
what plant is a characteristic fossil of the Eocene
Mangrove plant
what plants are present in Britain at the end of the Tertiary period
tropical flora gone, more typical European forest
