How does a new hypothesis replace an older explanation of something in the natural world

How does a new hypothesis replace an older explanation of something in the natural world? To understand this let us look at one of the classical example of geocentric theory and heliocentric theory. The geocentric theory states the Earth is at the centre of the solar system and the Sun, Moon, and all the other planets revolve around it. This ancient theory failed to explain the phenomenon like the phases of Moon, solar eclipse and lunar eclipse. The modern heliocentric theory which states that the Sun is at the centre of solar system, and all the planets including the Earth revolve around it. This theory was able to explain all the phenomenons unlike the geocentric theory. Hence the heliocentric theory replaced the geocentric theory.

the correct answer, according to e2020, is the second choice there is an occluded front in region a and a cold front in region b.

step 1: initiation

initiation is the beginning of transcription. it occurs when the enzyme rna polymerase binds to a region of a gene called the promoter. this signals the dna to unwind so the enzyme can ‘‘read’’ the bases in one of the dna strands. the enzyme is now ready to make a strand of mrna with a complementary sequence of bases.

step 2: elongation

elongation is the addition of nucleotides to the mrna strand. rna polymerase reads the unwound dna strand and builds the mrna molecule, using complementary base pairs. there is a brief time during this process when the newly formed rna is bound to the unwound dna. during this process, an adenine (a) in the dna binds to an uracil (u) in the rna.

step 3: termination

termination is the ending of transcription, and occurs when rna polymerase crosses a stop (termination) sequence in the gene. the mrna strand is complete, and it detaches from dna.