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.
C. A new source of freshwater
Explanation:
The situation that would most likely increase the carrying capacity for humans in a certain region is the availability of new sources of freshwater.
In ecological terms, the carrying capacity of a place is the the number of people, animals, or crops which a region can support without environmental degradation.
- A new source of freshwater provides new resources for the ecosystem.
- In the freshwater, more fishes are available, more plants can grow around and a lot of biological activities can progress.
- Water is essential for life.
- Fresh water sources are incentives for choosing to live in a place or not.
- A fresh water source increases the carrying capacity for humans in a certain region.
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Population changes brainly.com/question/2375366
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Outer core is the answer - Appex