Plants and the colonization of land
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almost always used to ward off attack of virus, predators, the plant doesn’t need it to survive directly but uses this as protection from the world
secondary compound
Why are plants important?
agriculture food drugs and medicine fossil fuels conversion of the sun's energy biodiversity
what is the basis of agriculture
plants
How does a bee help plants reproduce?
it acts as a messanger, carrying the pollen containing sperm from male flowers to female flowers hich receive the sperm
where are female and male flowers located on a plant and why?
The female flowers are towards the bottom of the plant as flowers can turn male after growing for a while so the younger flowers at the base of the plant are female
What is the study of plants called?
botany
What is our definition of a plant?
charophytes (green algae) chlorophytes (green algae) embryophytes (land plants)
What is it called when a non-photosynthetic eukaryote engulfs a photosynthetic cyanobacterium (a prokaryote, now called a plasmid)?
primary endosymbiosis
What is it called when a non-photosynthetic eukaryote engulfs a photosynthetic eukaryote?
secondary endosymbiosis
what are the types of photosynthetic eukaryotes?
red and green algae
Explain the oxygen revolution
no oxygen in atmoshphere • organisms (cyanobacteria) took in CO2 which was plentiful • produced oxygen • air became so oxygen dense it became toxic for some • oxygen helped create ozone layer, life slowly moved to land • natural give and take of CO2 and oxygen we have today
What happened 4550 million years ago
the earth formed
what appeared 3500 million years ago
photosynthesis (cyanobacteria)
What are the two things that happened 1500 million years ago?
First plasmid was engulfed by eukaryote red and green algae diverge
When did the colonization of land begin
500 million year ago
What are the shared features of all plants in this course ? • chlorophytes • charophytes • embryophytes
1) they use starch as energy 2) they all contain chlorophyll b 3) cellulose is a major component of the cell wall 4) thylakoids are in stacks called grana
What are the shared features of land plants and charophytes/ what are the features of land plants ancestors?
1) cells begin dividing from inside, not outside 2) plasmodesmat, the connection between cells 3) sperm structure 4) rose-shaped cellulose synthesizing complexes 5) sporopolleinin 6) peroxisome enzymes
What are features of land plants/ embryophytes that seperate them from other plants in this course?
1) the cuticle 2) jacketed sex organs called gametangia 3) embryophyte condition 4) alternation of generations
Why do plants use starch as energy and not sugar?
Sugar is a good storage molecule because it is easily metabolised and not very reactive, however they absorb and retain water. Starch are chains of glucose so starch can be easily be broken into sugar and starch is insoluble so no water problem
what is chlorophyll b
chlorophyll b is an accesory pigment that passes enrgy to chlorophyll a which all photosynthetic eukaryotes have
what is unbranched rediues of glucose?
cellulose
what is amylose?
straight chain residues of glucose, 20% of starch in plants
what is amylopectin?
branched linked residues of glucose, 80% of starch in plants
what is the most common organic polymer on earth?
cellulose