This is because blood is a SUSPENSION. Blood is composed of different type of particles with different densities. Blood is made up of platelets, white blood cells, red blood cells and the plasma. Blood is an heterogeneous mixture, which mean that all the components of the blood can be separated from one another. A suspension is a mixture which separate out when left standing; blood can be described as a suspension.
Globin 1 and globin 2 genes of insects are understood to have diverged approximately 170 million years ago, through duplication, from a common globin gene ancestor. The two genes that code for haemoglobin have conserved regions; oxygen-binding and heme- regions. Globin 2 gene has lost the intron region that is still present in the globin 1 gene. The percentage divergence is 7.2% with 20 varying nucleotides.
The invention that allowed scientists to study cells for the first time is the Microscope