<span>The delineation of an aquatic ecosystem is the process of spatial identification, mapping and recording of the site; description documents the critical components and processes that underpin the ecosystem values of the site, and develops conceptual model(s) and identifies threats.
Delineating an aquatic ecosystem often starts with defining the main aquatic elements (core elements). The core elements will often be distinct landforms or features such as a waterhole, a swamp, a lake or a river. Ecotonal areas may be included as part of the core element or may be considered as a separate zone. For example, riparian vegetation is often considered to be an integral part of a river ecosystem, even if only inundated in big flood events.
The area around the core elements that has a critical influence on ecosystem function is referred to here as the Ecological Focal Zone. Beyond this, the landscape may be usefully differentiated as a Zone of Influence and a Catchment Zone.</span>
Answer:
Option D, both A and B
Explanation:
The potential difference is created across a battery (between its two terminal –one positive and the other one negative) when work is done to move a charge from one point to another. This potential difference is measured in volts. 1 volt is the potential difference between two points when one joule of potential energy is spent to move a charge of one coulomb from one point to the other.
Voltage drop across a circuit is the amount of electric current lost due to resistance/ impedance with in the cables of the circuit.
Hence, both potential difference and voltage drop occurs across the circuit,
Option D is correct.
Answer:
It is pertinent to understand what hypertonic, hypotonic, and isotonic solution means before setting out to explain how a cell reaches equilibrium in each type of solution.
A hypertonic solution is one whose solute concentration is higher than that of the sap of a cell that is immersed in it.
A hypotonic solution is one with the same solute concentration as that of the sap of the cell immersed in it.
An isotonic solution has a lower solute concentration than that of the sap of the cell immersed in it.
In biological systems, water molecules move by osmosis from the region of higher water potential or lower concentration of solutes to the region of lower water potential or higher concentration of solute. An equilibrium is reached when there is no net movement of water between two sides. Hence;
A cell placed in a hypertonic solution will lose water to the surrounding solution until an equilibrium is reached. This means that such a cell will end up shrinking (wilting) or even dying due to loss of water from the cell sap.
A cell placed in a hypotonic solution will gain water from the surrounding solution until there is no net movement of water anymore. Such a cell might become turgid or even burst out its cell content.
A cell placed in an isotonic solution will neither gain nor lose water because the cell sap and the surrounding solution have equal solute concentrations.
Explanation:
C.75 of the cell's mass is water
