Endosymbiosis

Question 1

Evidence for endosymbiosis

Answer 1

1) MItochondria and chloroplasts have their DNA and arranged in a way similar to prokaryote and more specifically bacterial DNA
2)Mitochondria and Chloroplast size is similar to Bacteria
3) Mitochondria and chloroplasts can divide on their own and the way they divide is similar to binary fission

Question 2

Endosymbiont

Answer 2

A cell that lives within another cell called tHe host cell

Question 3

Endosymbiosis process

Question 4

Primordial soup

Answer 4

• In 1920s, chemists and scientist (Oparin and Haldane) hypothesised that:
• The early earth had a REDUCING (electron adding) atmosphere with gases from volcanic eruption.
• From which ORGANIC MOLECULES could have formed.
• Energy for this synthesis (from LIGHTING and UV RADIATION)
• Haldane suggested that the early oceans were a solution of ORGANIC MOLECULES, a “primitive soup” from which life arose.

Question 5

Hydrothermal vents

Answer 5

• Hydrothermal vents are found on the sea surface
• Hot water and minerals gush through these vents
  from beneath the Earth’s surface and into the
  ocean.
• “Black smoker” vents (300-400 ºC)
• Alkaline vents (40–90ºC)
• Could have been source of Organic compounds
• Chemical energy from a proton gradient (formed
  when alkaline fluid out of the vents mix with acidic ocean
  water)
• Could have fuelled many necessary reactions required
  for the assembly of organic molecules into early cells.

Question 6

Meteor

Answer 6

• Meteorites could also have been a source of organic molecules.
• E.g. Murchison meteorite landed in Australia
• source of organic material (e.g. amino acids. Simple sugars,
  nitrogenous bases).

Question 7

Protocells

Answer 7

They were Microspheres with organic and inorganic molecules inside it.
* Must have been able to REPLICATE and METABOLIZE … (key properties of life.)
* Needed BUILDING BLOCKS (e.g. Nucleotides) for RNA and DNA, and an
accurate method for replication of the genetic material for them to be
true living.
The first cell had Self-replicating genetic material (most likely RNA not DNA) and a metabolic source of (nucleotide) building blocks.