Life On Earth

Question 1

The most primitive form of life on earth

Answer 1

A group of bacteria known as archaea and archaebacteria, they were prokaryotic (unicellular without a nucleus), scientists think the earliest life forms probably originated around the warm water sprouts under the sea

Question 2

Why was photosynthesis so important:

Answer 2

1. Provides energy to almost everything in the global ecosystem
2. Life could now exist anywhere on earth
3. Light energy was used for this process
4. The only ground substance needed was water and carbon dioxide, which were both in abundance
5. Oxygen was produced as a waste product

Question 3

Why wasn’t there a balance between CO2 and O2

Answer 3

1. Not all dead organisms could decompose
2. Some were buried under layers of sediment to later turn into fossils
3. Carbon dioxide would bind to calcium in seawater

Question 4

How did the atmosphere change

Answer 4

1. The concentration of carbon dioxide decreased as the number of photosynthesising organisms increased
2. Concentration of oxygen increased
3. The levels of nitrogen in the atmosphere increased
4. Atmospheric pressure started to decrease
5. Increase in oxygen led to the ozone forming

Question 5

Eukaryotic

Answer 5

A multicellular organism that has a true nucleus

Question 6

The Cambric explosion

Answer 6

Multicellular animals probably developed from the colonies of unicellular organisms where cells became inseparable, and where certain parts or cells took over specific functions