evolution & development

Question 1

photosynthesis developed (3.5billion precambrian)

Answer 1

first organisms capable: cyanobacteria
resulted in oxygen(&ozone layer) + cell respiration

Question 2

First eukaryotes emerged:(1.5 billion yrs )

Answer 2

emerged by endosymbiotic theory: -> symbiosis of large primitive cell with smaller bacteria-> evolved into specialised structures in cell: mitochondriaand chloroplast

Question 3

due to Multicellular organisms: (700million yrs ago)

Answer 3

arised specialized cells and more complex structures in organisms
Division of labour of different cells
organisms became larger-get resources easier and fend off predators

Question 4

sexual reproduction(precambrian)

Answer 4

Some cells became specialised sex cells gametes->increased hereditary variation

Question 5

Cambrian explosion (paleozoic 540million)

Answer 5

aka megaevolution-> multicellular organisms -> major groups in animal kingdom (phyla) formed -> oceans full of life-> life radiated to land(first plants and fungi)