D. Oxygen
It refers to the pathway by which a chemical element is moved through both the abiotic and biotic compartment of an ecosystem.
After 20 years a resorted wetland can contain approx. 80% of plant biomass of a natural wetland.
Wetlands are one of the most endangered ecosystems in the world according to the UN and restoration is the only way to save these habitats.
The fact that restored wetlands can contain up to 80% of plant biomass shows how successful restoration programs can be.
Mature human sperm and ova are
similar in that they both have the same number of chromosomes. The human sperm
and ova are the reproductive cell in male and female respectively. The sperm
cells are motile while the ova are not. A mature human sperm and ova both contain 23
pairs of chromosomes.
