Answer:
The correct answer would be the slide should be almost in focus when changing to higher magnifications.
A parfocal lens is a type of lens which stays in focus when focal length or magnification is changed.
Parfocal microscopes are those in which objectives remain in focus even when magnification is changed for example, when it is switched from 10x to 40x, the object or slide remains at the focus.
Answer:
Natural selection
Explanation:
the process through which populations of living organisms adapt and change. Individuals in a population are naturally variable, meaning that they are all different in some ways.
Answer:
Eukaryotic cells are plants, animals, protists, fungi. Their genetic material is organized in chromosomes. Golgi apparatus, Mitochondria, Ribosomes, Nucleus are parts of Eukaryotic Cells.
Animals such as cats and dogs have eukaryotic cells.
Plants such as apple trees have eukaryotic cells.
Fungi such as mushrooms have eukaryotic cells.
Protists such as amoeba and paramecium have eukaryotic cells.
Insects have eukaryotic cells.
Humans are composed entirely of eukaryotic cells. Related Links: Examples.
Explanation:
Bacterial strains, especially Actinomycetes have been used in biotech production and drug discovery for years. Genetic methods now open the field of combinatorial biosynthesis that has improved impressingly in the past couple of years. Also, the productivity of yeast and other fungi in a variety of different processes has improved significantly since genetic methods have been introduced. In addition, a number of recent works considerably widens the potential of plant biotechnology. This review covers examples describing the use of prokaryotic cells and plant cells in biotech production.
Hope this helps! ^^
Prokaryotes: have a nucleoid and cellular DNA
Eukaryotes: have a nucleus and linear DNA and organelles
The correct answer would be Fluoride was not used to help protect teeth then
Cavity is not a genetic disease and thus there is no relevance of gene transfer in this case. Thus option A, B and D gets ruled out.
However, flouride in a limited amount is very useful for removing the cavities. Flouride in the foood and water enters the blood stream and make the teeth strong from inside. While the Flouride in Saliva make the teeths stronger and cavity free from outside. It reduces reminization that causes the loss of minerals.
Thus lack of flouride makes the teeth more cavity prone.