cyanobacteria and bifs

Question 1

what are BIFs

Answer 1

banded iron formations are distinct sedimentary rock structures consisting of alternating layers of iron-rich oxides (such as magnetite and hematite) and iron-poor cherts. they were deposited in shallow marine troughs or basins.

Question 2

describe Ediacaran fauna

Answer 2

soft bodied and rarely fossilised

Question 3

what did the cambrian period see the evolution of

Answer 3

shells, bones and other fossilisable hard body parts. evolution of vetebrates and movement onto land.

Question 4

what are cyanobacteria

Answer 4

cyanobacteria are a group of photosynthetic, prokaryotic microbes commonly found in aquatic habitats and moist soils. they contain chloroplasts that enable them to produce oxygen as a byproduct of photosynthesis.

Question 5

what are stromatolites

Answer 5

a type of layered organic sedimentary deposit formed by photosynthetic micro-organisms such as cyanobacteria.

Question 6

prokaryotic

Answer 6

lacking a nucleus eg. bacteria

Question 7

eukaryotic

Answer 7

has a nucleus

Question 8

how do stromatolites form?

Answer 8

some forms of cyanobacteria secrete a calcium carbonate slime solution that traps layers of sediment, causing the rest of the microbial colony to grow towards the light. over thousands of years, this builds into layered biochemical structures known as stromatolites. often dome shaped or wavy, due to direction of growth towards light.

Question 9

describe the conditions on early earth

Answer 9

no free oxygen, atmosphere of methane, ammonia, carbon dioxide, nitrogen, hydrogen
Violent storms and strong UV rays from the sun