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:
Because some of them are immune and only works for one thing in the system
The term ‘Crossing over’ was used by Morgan and Cattell. It is a process in which there is exchange of chromosome segments between non-sister chromatids of a homologous chromosomes. It occurs during pachytene stage of prophase I of meiosis cell division.
Significance of crossing over:
- Crossing over provides genetic variation in all sexually reproducing organisms.
- It creates new combination of genes or genetic recombination and produces hybrids.
"(1) Human population growth reached 6.8 billion in 2010 and it continues to increase" is what led to the other <span>three, since all of these happen from human activity. </span>
