General Questions Flashcards
What part did chlorophyll containing Cyanobacteria, play in the Earth’s environment and evolutionary history?
The appearance of chlorophyll-containing Cyanobacteria created a ‘safety-net’ for heterotrophs who run the risk of consuming all available resources. These Cyanobacteria uses photosynthesis to create their own organic molecules. This produced oxygen in the atmosphere; favoured by complex life, which could use the high-oxygen atmosphere as a more efficient way of synthesising ATP (aerobic respiration).
What is the ‘prebiotic soup’ ?
A theory proposed by Alexander Oparin and J.B.S Haldane. Which proposes that environmental conditions on Earth (such as high UV radiation and large quantities of lightning events) caused Methane (CH4), Ammonia (NH3), Water (H20) and hydrogen (H2) to react with each other forming Amino Acids, which to this day are used by cells to create proteins for life.
Who is LUCA? And what made it successful in comparison to is earlier ancestors?
LUCA is the Last Universal Common Ancestor. It contained either DNA or RNA and its success can be attributed to the ability to form a cellular membrane so that there could be a barrier between the interior and exterior, therefore controlling what enters and leaves.
What is the difference between Eukaryotic cells and Prokaryotic cells?
Eukaryotic cells contain membrane-bound organelles.
Prokaryotic organelles are not bound by a membrane
Eukaryotic cells have DNA contained within the nuclei membrane .
Prokaryotic cells have no membrane, therefore the DNA is contained within the cytosol.
Plants and Algae are Eukaryotes. They have Ribosomes, centrosomes etc which are all bound by cell membranes.
But what differs then from other organisms within the kingdom?
Most eukaryotes have a mitochondria which is the power-house; producing ATP. But plants and algae have Plastids instead. Chloroplasts are a type of plastid.
