The graph shown represents the population growth curves of two different species of aquatic
organisms, A and B. What is a valid prediction
based on this graph?
Species
species
в
Population size
January
Apr
Saplombier
A. Species A will not be present in the water
during the winter months.
В.
Species A will eliminate species B from the
water after 1 year.
C. Species B will attain maximum population
size each autumn due to a decrease in w'acer
temperature.
D. Species B will decrease in population size
approximately 1 month after a decrease in the
population size of species 4.

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.

it provides an alternative energy pathway for the reaction to proceed.

a catalyst is a substance that speeds up the rate of a chemical reaction but is not consumed during the course of the reaction.

catalysts increase the rate of reaction without being used up. they do this by lowering the activation energy needed. with a catalyst, more collisions result in a reaction, so the rate of reaction increases. different reactions need different catalysts.

a catalyst works by providing an alternative reaction pathway to the reaction product. the rate of the reaction is increased as this alternative route has a lower activation energy than the reaction route not mediated by the catalyst.

high growth (apex)