The Eukarya domain.
The organisms can be divided into three domains, based on the type of cell that the organism is made of:
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Bacteria domain: cells do not contain a nucleus.
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Archaea: cells don't contain a nucleus and they have a different cell wall from bacteria.</span><span>
Eukarya: </span></span>They keep their genetic material inside the nucleus. Composed by animals, protists, plants and fungi
Answer: All the above options are correct about the characteristics of Lumbriculus variegatus.
Explanation:
Lumbriculus variegatus also called the black worm belongs to the phylum Annelida and is used by biologists to illustrate:
-blood vessel pulsations,
-swimming reflex,
-peristaltic crawling behavior,
-giant nerve fiber action potentials.
These studies where carried out on them due to the characteristics they possess. These includes:
-its blood circulates in a closed circulatory system
-Freshwater worm found throughout North America and Europe
-Prefers the shallow habitats found at the edges of ponds, lakes, or marshes
-Feeds on decaying vegetation and microorganisms.
Four conditions are needed for natural selection to occur: reproduction, heredity, variation in fitness or organisms, variation in individual characters among members of the population. If they are met, natural selection automatically results.
