It was ancient fossils containing ----Ancient bacteria---
Ans.
Neural crest cells are embryonic cells that are unique to organisms of phylum chordata. These cells give arise a number of cell lineage, such as bone and cartilage, melanocytes, smooth muscle, glia and neurons, eyes, teeth, and other sense organs. The neural crest cells do not form pharyngeal slits in invertebrate chordates.
Thus, the correct answer is option b).
Answer:
1.2 mL
Explanation:
<em>This is a problem of simple dilution. The dilution principle simply agrees that the number of moles before dilution must be equal to the number of moles after dilution.</em>
Recall that: number of moles = mass/molar mass or molarity x volume.
Hence, for the dilution principle:
initial molarity x initial volume = final molarity x final volume.
In this case, initial molarity of NaOH = 1 M, initial volume = ?, final molarity = 0.1 M, final volume = 12.0 mL.
Initial volume = final molarity x final volume/initial molarity
= 0.1 x 12/1 = 1.2 mL
It thus means that 1.2 mL of 1 M NaOH would be taken and then diluted up to 12.0 mL mark by the addition of distilled water in order to produce 12.0 mL, 0.10 M NaOH solution.
Answer:
Option D, The work done by each force is negative
Explanation:
When both the forces are negative, then irrespective of which force is large or small, the net force will definitely negative. A negative force indicates reduction in kinetic energy of particle. Since mass is constant , it is the speed which reduces and produces negative work. Reduction in speed is contrasting to the statement give in the question. Hence, option D is not possible.
