Match the following
Column- 1 | Column-2 (Brain Capacity) |
$(P)$ Homo eractus | $(a)\; 1400 \;cc$ |
$(Q)$ Homo habilis | $(b)\; 900 \;cc$ |
$(R)$ Neanderthal Man | $(c)\; 650-800 \;cc$ |
$(S)$ Modern Homo Sapience |
Connecting link between Annelida and Mollusca is
How has the free ${O_2}$ been released into the earth's atmosphere whereas there was no free ${O_2}$ at the time of origin of life