Q3. (a) some research has shown that increased use of computers and other digital media can affect
eyesight and reaction times.
a scientist wanted to test if prolonged use of a computer affected reaction time.
the scientist tested the reaction times of 10 people under the same environmental conditions.
these people then used a computer for three hours.
the scientist tested their reaction time again.
give three ways that the scientist could improve this method to determine if prolonged use of a
computer affects reaction time.

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.

answer: substrate concentration. enzymes work best when there is a high enough substrate concentration for the reaction they catalyse.

well for one plants are always the producer, so a is the answer. a wolf is more of the consumer(predator) and the deer is the prey so i know those two are out of the question. also mushrooms are fungi/fungus so a is the producer.