Because freezing will often burst the cell walls and destroy tissue. The crystals of ice are very sharp and hard to control AFAIK. Note what happens to a banana or many types of fruit after you dethaw — it becomes all mushy and not of the same structure, fiber and cell form as before, like a bad beam up in Star Trek.
The process where a specie develops and evolves into new many species is termed as speciation. Macroevolution explores the mechanism of speciation where organisms across biological populations evolve as distinct population.
There are many causes to speciation, a) geographic isolation, b) gene flow reduction, and c) reproductive isolation.
Answer:
defines the problem to be explored
Multicellular organisms are referred to as eukaryotes while the opposite, unicellular organisms, are called prokaryotes. Among all the kingdoms, I believe the kingdom which all organisms are multicellular are Animalia and Plantae.
Answer:
The question to be asked an investigated when observing a structure under the microscope to determine whether it is living is if it has a nucleus if eukaryote or nucleoid if prokaryote.
Explanation:
The major organelle that must be present in all living cells is the nucleus or nucleoid and the protoplasm. The observation of the cell under the microscope will show the subcellular entity, nucleus/nucleoid, more pronounced than other organelles in the cell. The nucleus house the necessary information for the maintenance and reproduction, which is mainly the genetic information that dictates the translational protein products that are needed to build another aspect of the cells. Therefore, when such a tiny structure is placed under the light microscope under the view of oil immersion, the nucleus of the cell should be visible if it is a living structure.