SCIENCE
VIRUS AND BACTERIA
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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They are probably unable to make humans sick
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They probably have no DNA in their cells
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They are probably poorly adapted to their environments
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They probably can’t be seen without a microscope
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Detailed explanation-1: -A protozoan is what we call a eukaryotic organism because it is a cell that contains a true nucleus and is bounded by a nuclear membrane. It consists of only a single cell and is so small that we usually can’t see it without using a microscope.
Detailed explanation-2: -What can you infer about protozoans from the fact they are single celled organisms? They probably can’t be seen without a microscope.
Detailed explanation-3: -Historically, protozoans were regarded as “one-celled animals", because they often possess animal-like behaviours, such as motility and predation, and lack a cell wall, as found in plants and many algae.
Detailed explanation-4: -Protozoa are one-celled animals found worldwide in most habitats. Most species are free living, but all higher animals are infected with one or more species of protozoa. Infections range from asymptomatic to life threatening, depending on the species and strain of the parasite and the resistance of the host.
Detailed explanation-5: -Protozoa are single celled organisms. They come in many different shapes and sizes ranging from an Amoeba which can change its shape to Paramecium with its fixed shape and complex structure. They live in a wide variety of moist habitats including fresh water, marine environments and the soil.