Answer:
A. Lancelet
B. All chordates
Explanation:
A. Dorsal nerve chord is the only <u>unique feature</u> among all members of <u>phylum chordata</u> (mainly found in subphylum Vertebrata). In the given list, only lacelet is the Chordate whereas <u>snail belongs to phylum Mollusca</u>, <u>grasshopper belongs to Arthropda</u>, and <u>jellyfish belongs to Cnidaria</u>. Dorsal nerve cord runs along the length of organism's body.
B. <u>Gill slits</u> are <u>opening structures</u> to gills through which water passes from pharynx/throat to exterior. Their main purpose is to help filter the food particles available in surrounding water. Although they are typical for amphibians and fishes, chordates also possess gill slits at embryonic stages.
Energy is lost at each trophic level.
Answer:
This poisonis an example of an aboitic factor
Abiotic are the non-living physical and chemical factors that can affect the ecosystem, such as amount of water, temperature, amount of sunlight, etc.
Biotic are the living organisms inside the ecosystem, and can include humans, animals, and plants.
~
