PPQ's Flashcards
What is a specimen called when its on the stage of an optical microscope? (1)
A. Image.
B. Slide.
C. Object.
C - Object.
How many glass lenses are there in an optical microscope? (1)
A. 1.
B. 2.
C. 4.
B - 2, the eyepiece and objective lens.
What can the objective lens be immersed in to increase the resolving power of the lens? (1)
A. Oil.
B. Water.
C. Methylene Blue.
A - Oil.
Why is the resolving power of an electron microscope higher than an optical microscope? (1)
A. Because it is more expensive.
B. Because there are more lenses.
C. Because the wavelength of light rays is longer than the wavelength of electron beams.
C - Because the wavelength of light rays is longer than the wavelength of electron beams.
What does TEM stand for? (1)
A. Travelling electron microscope
B. Transmission electron microscope
C. Tilting electron microscope
B - Transmission electron microscope.
What are SEM used to study? (1)
A. Surface of cells.
B. Living cells.
C. Internal structure of cells.
A - Surface of cells.
What are used to focus electron beams onto photographic screens? (1)
A. Focusing wheel.
B. Anode.
C. Electromagnets.
C - Electromagnets.
How many times can an electron microscope magnify an object without losing resolution? (1)
A. 25x
B. 2,500x
C. 250,000x
C - 250,000x
Which of the following could you use either an optical microscope for an electron microscope to examine? (1)
A. Mitochondrion.
B. Frog eggs.
C. Ribosome.
A - Mitochondria.
Which type of point mutation does not result in a frame-shift? (1) A. addition B. deletion C. insertion D. substitution
D - Substitution.
What property of the genetic code means that mutations may not result in a change in protein structure? (1)
Degenerate.
Which of these is only a property of prokaryotic DNA? (1) A. Not associated with histone proteins B. Contains the bases A, T, C and G C. Linear chromosomes D. contains promoter regions
A - Not associated with histones.
Which enzyme catalyses the formation of phosphodiester bonds during transcription? (1)
RNA polymerase.
What is the function of DNA helicase? (1)
Breaks hydrogen bonds.
What is the function of DNA polymerase? (1)
Forms phosphodiester bonds.
DNA replication is… (1)
A. Conservative
B. Semi-conservative
C. Dispersive
B - Semi-conservative.
What type of nucleic acid transports amino acids to the ribosome? (1) A. mRNA B. tRNA C. rRNA D. DNA
B - tRNA.
What is an anticodon? (1)
A. sequence of three nucleotides on mRNA which code for an amino acid.
B. sequence of three nucleotides on tRNA that are complementary to a codon.
C. sequence of three nucleotides in DNA which code for an amino acid.
B - Sequence of three nucleotides on the tRNA that are complementary to a codon.