The process of copying genetic information from one strand of DNA into RNA is termed as
- A.translation
- B.transcription
- C.replication
- D.mutation
Correct answer
Explanation
The correct answer is B, transcription. Transcription is the step in which the genetic message of a gene is copied from one strand of DNA into a strand of RNA.
The flow of genetic information in a cell, called the central dogma, runs DNA → RNA → protein. In transcription the enzyme RNA polymerase reads one strand of DNA, the template strand, and builds a matching messenger RNA, using uracil in place of thymine. In eukaryotes this happens in the nucleus. The messenger RNA then carries the message to the ribosomes in the cytoplasm, where it is used to make a protein.
A is wrong: translation is the next step, in which ribosomes read the RNA code to join amino acids into a protein.
C is wrong: replication is the copying of the whole DNA into new DNA before a cell divides.
D is wrong: mutation is a sudden change in the DNA sequence, not a copying process.
Exam tip: replication DNA → DNA, transcription DNA → RNA, translation RNA → protein.
Practice Questions
View allThe speed of the wind is measured by
- A.wind vane
- B.wind rose
- C.barometer
- D.anemometer
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An anemometer measures how fast the wind is blowing; its name comes from the Greek word anemos, meaning wind.
Read the full explanation →Brilliance of diamond is due to
- A.interference of light
- B.diffraction of light
- C.polarization of light
- D.total internal reflection of light
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Light that enters a cut diamond is reflected again and again inside it before it escapes, which makes the stone sparkle.
Read the full explanation →Which one of the following is NOT an electromagnetic wave ?
- A.Light wave
- B.Radio wave
- C.Sound wave
- D.Micro wave
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Sound is a mechanical wave that needs a medium to travel, while the other three are electromagnetic waves. Sound travels as a longitudinal wave of compressions and rarefactions in air, water or solids, which is why it cannot pass through a vacuum.
Read the full explanation →Which one of the following is NOT true for an electromagnetic wave ?
- A.Electromagnetic wave transports energy and momentum
- B.Electromagnetic wave can be polarized and reflected
- C.Electromagnetic wave is longitudinal
- D.Electromagnetic wave propagation is described by the varying electric and magnetic fields
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Electromagnetic waves are transverse, not longitudinal, so this statement is false. In an electromagnetic wave the electric field and the magnetic field oscillate at right angles to each other and both at right angles to the direction in which the wave travels.
Read the full explanation →Which one of the following frequency ranges is sensitive to human ears ?
- A.0-200 Hz
- B.20-20,000 Hz
- C.200-20,000 Hz only
- D.2,000-20,000 Hz only
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The normal human ear hears sound from about 20 hertz to 20,000 hertz, the audible range. Frequency, measured in hertz, is the number of vibrations per second, and it decides the pitch of a sound: the higher the frequency, the shriller the note.
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