Topic 9 - Plants Conquer Land/ Bryophytes Flashcards
What are photoautrophs?
- the vast majority of the kingdom Plantae species.
- organisms that carry out photosynthesis.
- Using energy from sunlight, carbon dioxide and water are converted into organic materials to be used in cellular functions such as biosynthesis and respiration
what is a terrestrial environment?
- an environment that is solely made up of landforms. It refers to the land area of the earth, which includes both artificial and natural surfaces.
what were the first photosynthesizers that transitioned from water to land were rewarded with bounteous habitat?
- bright sunlight unfiltered by water and suspended material.
- atmosphere with an abundance of carbon dioxide.
- soil rich in mineral nutrients
- at first relatively few herbivores or pathogens. so no organism to eat them.
what were the very first terrestrial photosynthesizers were?
- cyanobacteria for 1.2 BYA.
what are isolated spores?
- there are a lot in terrestrial sediment samples.
- they are in clumps of 2 or 4.
- spores were found embedded in tissue that looks like true plant tissue for 450 MYA.
- spore is used for a single-celled propagule that can grow to a
larger (usually multicelled) individual without having to fuse with another cell first
what are the 4 main groups of extant plants?
- non-vascular plants
- seedless vascular plants
- gymnosperms
- angiosperms
- 3 and 4 –> monophyletic
- 1 and 2 –> paraphyletic
what does the kingdom plantae share a common ancestor with?
- green algae.
- within green
algae, plants are
most closely
related to
charophytes
what are charophytes?
- the group of green algae whose ancestral lineage gave rise to land plants
what are three of the shared features of charophytes?
- they have rosette-shaped cellulose-synthesizing protein complexes. (make the cellulose microfibrils of the cell wall)
- the structure of the plant sperm of charophytes (only for those that have flagellated sperm.
- both plants and charophytes have a phragmoplast that forms during cell division.
what is the phragmoplast?
- phragm = barrier
- it helps construct the cell plate between the daughter cells, which goes on to become a new cell wall
what is the cutoff for plant?
- some systematists put chlorophytes,
charophytes and embryophytes together
as Kingdom Viridiplantae - virid = green
- the charophytes and plants are within the kingdom plantae just for embryophytes.
what is the first synapomorphy of members of kingdom plantae are:
- Multicellular, dependent embryos.
a. zygotes are retained within tissues of the
female parent, develop into embryob. embryo has specialized placental cells
and depends on parent for nutrients
what is the second synapomorphy of members of kingdom plantae are:
- alteration of generations.
a. this refers to the life cycle that has both multicellular haploid cells and a multicellular diploid body.
what are the steps of alternation of generations?
- you start off with a gametophyte and the gametophyte makes gametes through mitosis.
- The gametes fertilize and form a diploid zygote via mitosis.
- then through mitosis a diploid sporophyte is made.
- sporophytes make spores through meiosis which are haploid.
what is the third synapomorphy of members of kingdom Plantae are:
- sporopollenin
- they are tough stable polymer in walls of plant
spores, including pollen - there is no sporopollenin in spores of
charophytes
a. sporopollenin is present in walls
of charophyte zygotes - some other derived features are
synapomorphies of large clades within the
Plantae but are not shown by all plants
what is the other name?
- kingdom embryophyta
what is the first derived feature of Plantae?
- adaptations for water conservation.
- they have waxy cuticle on the epidermis and acts as waterproofing. (it also protect the plant from microbial attack)
- stomata pores in the epidermis of leaves and other photosynthetic organs. (allows gas exchange between air and leaf interior. )
what does the stomata pores allow?
- water to exit via evaporation
- change in shape of cells broadening stomata can reduce the size of the openings
- stomata = mouth
what is the second derived feature of planate?
- lignifies vascular tissue for internal transport.
- they contain lignin which adds strength and ridgity.
what is lignin?
- a complex polymer of alcohol
what are the two main types of vascular tissue?
- xylem cells carry water and minerals up from dead roots.
- phloem cells distribute organic products in living cells.
what is the third derived feature of planate?
- they have apical meristems (have the capacity to become different tissues)
-the apical meristem is a complex structure at tip (=apex) of shoots and roots.
what are meristems?
- they are undifferentiated tissue from which new, differentiated cells arise.
- meristems are simple in non-vascular plants.
Are resources more compartmentalized in terrestrial compared to aquatic habitats?
true
what are the three extant phyla of nonvascular plants?
- phylum Hepatophyta, liverworts. (hepato= liver, phyta =plant)
- Phylum Anthrocerophyta, hornworts (ceros =horn)
- phylum bryophyta, mosses. (bryo =mosses)
what is a bryophyte?
- refers to only one phylum, but informal term bryophyte refers to all non-vascular plants.
what are hornworts thought to be a sister taxa group to?
They are sister taxa with vascular plants.
what do bryophytes lack?
- lack true vascular tissue therefore they are low-growing plants because their tissues are unable to support much weight.
-water, gases and nutrients can’t be transported around
the body of a bryophyte, so they have to be absorbed or
created by each cell or by an adjacent cell
how thick are bryophyte tissues?
- one or few cells thick
what is the dominant phase of life cycle for a brophytes?
- haploid (1N) gametophytes
what organs do bryophyte gametophytes have
for making eggs and sperm?
- ‘female’ archegonium produces a single egg
- ‘male’ antheridium produces many flagellated
sperm
in what type of environment do bryophytes need to live in to reproduce sexually ?
- moist places
what is the moss life cycle in steps?
- you start off with haploid spores
- The male gametophyte has antheridia which produces sperm. The female gametophyte has an archegonia which produces eggs.
- Together the haploid sperm and the haploid eggs get fertilized within the archegonium.
- Then a diploid zygote is formed.
- A diploid embryo is developed
- a diploid young sporophyte is developed
- This produces diploid female gametophytes and mature sporophytes.
- From the diploid mature sporophyte the haploid sporangium is released.
what do sphagnum moss form?
- it forms extensive deposits of organic material called peat.
what is a peat?
-decayed organic matter
what is a muskeg?
- peat bogs
what inhibits bacterial growth in sphaagum?
- phenolic compounds and acidic secretions.
- this make sit hard for bacteria to decompose
what are sphagnum good for?
- it has a good absorptive nature. , it can be used as diapers, menstruation pads and antiseptic binding for wounds.
what is peats used as?
- used as fuel, it can be dried and then you can burn it.
what else can sphagnum be used for?
- for soil conditioner b/c of water storage capacity of its large dead cells.
- it can maintain water levels
What happens to Co2 levels when peatlands are lost?
- the co2 levels increase as loss of peatlands b/c forest fires cause more co2.
