Final answer:
Specimens are killed and preserved in solutions such as formaldehyde for biological study, although due to health risks, safer alternatives are now used.
Step-by-step explanation:
A specimen is typically killed and placed in a preservative solution for later analysis in the field of biology. Formerly, methanal or formaldehyde was commonly used as a biological preservative for this purpose. Chemical fixation with substances like formaldehyde effectively kills microorganisms and preserves tissue samples by stopping degradation and maintaining their structure for microscope examination. However, due to the dangers associated with formaldehyde, such as its carcinogenic properties, safer alternatives are now used for preservation. Other preservation techniques for biological specimens include heat-fixing and fixatives like ethanol, methanol, acetone, or safer aldehyde-formaldehyde alternatives, which serve to denature proteins and stabilize cell structures