Lecture 2: The Diversity of Life Flashcards
What are the characteristics of life? (8 things)
Cellular Organisation Reproduction Metabolism Homeostasis Heredity Response to Stimuli Growth and Development Adaptation through evolution
How big are Eukaryotes?
10-100µm
How big are Prokaryotes?
less than 5µm
How big are organelles? (e.g Mitochondria and Chloroplasts)
Mitochondria: 1-10µm
Chloroplasts: 2-5µm
1µm=?
1000 nm
What is Evolution
When you have organisms that vary, pass on their characteristics
and survive differentially, you get evolution
The key issues in the origin of life are how information that codes for
life’s functions can be copied and passed on
Once replicating organisms arrive, evolution does the rest
What did Darwin Propose?
Darwin proposed ‘Natural
Selection’ as a mechanism
for evolution.
What do you require for Natural Selection?
Variation - Individuals in a population vary from one another.
Inheritance - Parents pass on their traits to their offspring
genetically.
Selection - Some variants reproduce more than others.
Time - Successful variations accumulate over many
generations.
What is Endosymbiosis?
Key thing to know is that two of our organelles in eukaryotes are derived from bacteria.
Mitochondria are from proteobacteria
Chloroplasts from cyanobacteria
Do Eukaryotes or Prokaryotes have membrane enclosed organelles?
Eukaryotes
Is the Nuclear Envelope present in the three domains of life? (Bacteria Archaea Eukarya)
Bacteria: Absent
Archaea: Absent
Eukarya: Present
Is the Membrane-enclosed Organelles (Bacteria Archaea Eukarya)?
Bacteria: Absent
Archaea: Absent
Eukarya: Present
Is the Peptidoglycan in cell wall of (Bacteria Archaea Eukarya)?
Bacteria: Present
Archaea: Absent
Eukarya: Absent
Are there circular chromosomes in (Bacteria Archaea Eukarya)?
Bacteria: Present
Archaea: Present
Eukarya: Absent
