The compound that was formed by the reaction of the first oxygen released by Cyanobacteria and iron are the metals of the earths crust. Cyanobacteria was the first organisms that used water instead of hydrogen sulfide or other compounds as a source of electrons and hydrogen for fixing carbon dioxide. Early Cyanobacteria inhabited marine sediments where Archean banded iron formations were deposited; consisting of reddish layers rich in iron oxide.
Answer:
All living things are made up of cells.
cells are the basic unit of structure and function of ll living things.
All cells are come from other cells.
Explanation:
The cell theory is historic scientific theory and is universally accepted. This theory was given by Robert Hook in 1665. According to this theory all living things are made up cells.
Cell:
Cell is the smallest unit of life and it is building block of life.
This theory consist of following points:
All living things are made up of cells.
Cells are the basic unit of structure and function of ll living things.
All cells are come from other cells. Which means that cells are originated from pre-existing cells.
The other given options:
Cells comes from nonliving matter.
Cells make up most organisms bu not all.
These are two are not the postulate of cell theory because all living organisms are made of cells.
We can get the Ka value from this formula:
Ka = [H+] [A-} / [HA]
So we need to know [H+] & [A-] & [Ha] to get the Ka value
[H+] = 2.9 * 0.52/100 =0.01508 M
and when [H+] = [A-]
∴[A-] = 0.01508 M
∴ [HA] = 2.9 - 0.01508 = 2.88 M
So by substitution:
Ka = [0.01508][0.01508] / 2.88
= 7.9 x 10^-5
