A covalent bond forms when two non- metal atoms share a pair of electrons. Substances with covalent bonds often form molecules with low melting and boiling points, such as hydrogen and water.
D. anticodons................
Mice that are deficient for Apaf1 or caspase-9 are defective for cytochrome dependent apoptosis. Apoptosis is a critical event in development, allowing excess brain cells to be weeded out. The extent of brain overgrowth and the size of the cranial protrusions indicate that the pruning process in the developing brain must be massive. The dramatic effects of the deficiencies of Apaf1 and caspase-9 suggest that the cytochrome c-dependent apoptotic pathway the intrinsic pathway must be critically important in brain development.
Answer:
Declining biodiversity lowers an ecosystem's productivity (the amount of food energy that is converted into the biomass) and lowers the quality of the ecosystem's services (which often include maintaining the soil, purifying water that runs through it, and supplying food and shade, etc.).