Not true, certain chemical transmitters stimulate certain receptors
Answer is Middle Paleozoic era.
Paleozoic era was in 542 Ma - 245 Ma and it has 6 periods as Cambrian, Ordovician, Silurian, Devonian, Carboniferous and Permian.
360-280 Ma - forming of vascular plants with woody tissues, seeds and veins.
430 - 410 Ma - forming of jawed fishes and first amphibians.
420 Ma - forming of scorpions
360 Ma - forming of crustaceans.
C. The temperature remains the same.
The antibiotic called ampicillin was not effective against E.coli.
Answer: D
Explanation:
E.coli is normal microbial flora which is present in the gut of the mammals.
It is gram negative bacteria and very few strains of this bacteria causes harm.
Antibiotics are the chemical drugs which are used to treat the microbial infection either by killing the causative organism or by its growth inhibition.
Antibiotics such as neomycin, penicillin and erythromycin are usually used to treat E.coli infection.
Antibiotic such as Ampicillin is not used as the bacterium E.coli is highly resistant to it.
Through leaching. B horizons or subsoil get materials from above through accumulated rain water that leached these materials and precipitated it into the B horizon.