The correct answer is option A, that is, jaw or jawless fishes.
Agnatha refers to the superclass of jawless fish in the phylum Chordata, subphylum Vertebrata, comprising of both the extinct (conodonts and ostracoderms) and present (cyclostomes) species. It comprises the group of all vertebrates with jaws, that is, gnathostomes.
On the other hand, there are two categories of living fish with jaws. The Osteichthyes (the bony fish) and the Chondrichthyes (the cartilaginous fish). Both the categories of fish comprises of two pairs of lateral fins and a finned tail for impulsion in water.
Protists are unicellular eukaryotes, whereas Eubacteria and Archaebacteria are unicellular prokaryotes.
Eubacteria and Archaebacteria belong to kingdom Monera; whereas Protists belong to kingdom Protista.
All Monerans have prokaryotic cell structure. Protists have eukaryotic cell structure and are unicellular.
Protists either lack cell wall or have cell wall made up of cellulose.
Eukaryotes have cell wall made up of peptidoglycan or murein.
In Archaebacteria cell wall lacks peptidoglycan but contains proteins and non-cellulosic polysaccharides.
Protists have typical sexual reproduction involving fusion of gametes. In Eubacteria and Archaebacteria typical sexual reproduction is absent.
Cell division is mitotic type in Protists and amitotic in Eubacteria and Archaebacteria.
The answer to this question would be: <span>(2) cytoplasm
The nucleus is the organelle in middle of the cell that contains DNA. The ribosome is organelle that has a function in protein synthesize. Mitochondrial has a function in making the energy. Cytoplasm is water inside the cells. Everything would be stored inside it and moving material will need to pass it.</span>
Answer:
<u>acetylcholine</u>
Explanation:
In the pre-synaptic knob there are vesicles which contain a transmitter substance called acetylcholine. When an impulse reaches the synaptic knob, it stimulates the vesicles to move towards the pre-synaptic membrane releasing the acetylcholine.
The transmitter substance makes the membrane permeable. The neuromuscular junction contains the sensory neurone(afferent), motor neurones(efferent) and the relay neurones(connector).
