Classification of Organisms & Carbon and Energy Sources Flashcards
(226 cards)
What were the originally (but wrong) 5 Kingdoms of Life and how were they organized?
Monera, protista, fungi, plantae, animalia and they were classified by their morphology (looks) and nutrition (metabolism).
What are the Three Domains of Life and how are they classified?
Bacteria, Archaea, Eukaryota and they are classified by molecular information (ribosomal RNA gene sequences).
Which type of cell has a higher surface area to volume ratio?
Prokaryotes have a greater surface-area to volume ratio.
As cell size increases, what happens to surface area to volume ratio?
It decreases and thus the cell becomes less efficient.
How do Eukaryotic cells survive although having a much lower surface area to volume ratio than prokaryotes?
They have separate membranes that carry out specific function like energy production.
What organelles are present in prokaryotic cells?
Plasma membrane, ribosome, cytoplasm and nucleoid
What is the nucleoid?
It is DNA or genetic information that is not bound in a membrane.
Where did the mitochondria and chloroplast orginate from?
They came from prokaryote organisms that most likely were engulfed by the ancestor of eukaryotes.
What is definite proof that the mitochondria and chloroplast originate from an eukaryote engulfing or combining with a prokaryote?
The DNA of these organelles are unique and different from our DNA.
What is the Endosymbiotic Theory?
The theory that some eukaroyte organelles, mainly the chloroplast and mitochondria, originated from prokaryotes.
How are bacteria and archaea different from eukaroytes?
They lack a membrane bound nuclei, have no energy-producing organelles and have no true sexual reproduction.
What are the special features of a bacteria cell?
They have circular DNA, have a plasmid, have no nucleus, no membrane, no energy-producing organelles and a cell wall made of peptidoglycan.
What is the bacteria cell wall made of?
Peptidoglycan
Why are bacteria cells so small?
In order to make diffusion to be as efficient as possible.
What is diffusion?
The movement of particles from a high area of concentration to an area of low concentration.
What is horizontal gene transfer?
It is the major source of bacterial diversity. It is the transfer or exchange of genes between bacteria.
How do bacteria reproduce?
By binary fission.
What is the pilus?
A structure that connects bacteria and allows them to exchange and transfer genes generally from the plasmid.
What is the plasmid?
It is an extra set of circular genetic material that most bacteria have. They are usually not essential to survival but they give the bacteria adaptive advantages.
What is conjugation?
The method of DNA transfer from bacteria cell to bacteria cell through the pilus. (Mainly from plasmid)
What is transformation?
When cells take up DNA released from cell breakdown, it generally requires large amounts of heat.
What is transduction?
The process in which a virus incorporates its genetic material into its host.
What distinguishes archaea from bacteria?
They have a unique ribosomal RNA structure, cell wall that is not peptidoglycan and they can live in extreme conditions.
How does intestinal bacteria help the human body?
They can help with digestion, secretion of vitamins, absorbance of biomolecules and guide development of our intestine lining.