Explanation:
In thermoplastics, the arrangement of monomeric units is linear and in thermosetting plastics, it is cross-linked. Thermoplastics are usually soft, weak and less brittle, so can get soften on heating and stiffen on cooling. They can be melted, remoulded and recycled easily.
Answer:
4 I think
Explanation:
The cytoplasm is home to many activities of the cell as it contains molecules, enzymes that are crucial in the break down of the waste. The cytoplasm also assists in metabolic activities. Cytoplasm provides shape to the cell. It fills up the cells thus enabling the organelles to remain in their position.
A variation is a reference to the differences or deviations, such as the structure and form, as for crossing over is the exchange of genetic material between the non-sister chromatids of the homologous chromosomes during meiosis.
Answer: C
Explanation: The process that occurred in the lake is natural selection. In the presence of an external environmental influence such as pollution, only the trouts that were fit to survive or in other words those that have the alleles that help in adapting to the new conditions live and increased in numbers. In such a case, one can say the fittest of the organisms survived and the corresponding allelic frequency in that population increased over time. The organisms carrying the other alleles died due to pollution and hence the overall frequency of alleles change.