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.
What catalyses the formation of peptide bonds between amino acids in translation? (1) A. DNA polymerase B. RNA polymerase C. protease D. ribosome
C - Protease.
Where does transcription occur? (1) A. Nucleolus B. Nucleus C. Ribosome D. Spliceosome
B - Nucleus.
What type of sugar is found in DNA? (1)
Deoxyribose.
Which pair of scientists demonstrated experimentally that DNA replication is semi conservative? (1)
Messelson and Stahl.
What is the process of mRNA formation called? (1)
A. Replication
B. Translation
C. Translation
B - Translation.
Which domains carry out post-transcriptional modification of mRNA?
A. eukaryotes only
B. prokaryotes only
C. both eukaryotes and prokaryotes
A - Eukaryotes only.
What is the first stage in DNA replication? (1)
Unwinding of the double helix (to allow hydrogen bonds to break).
What base pairs with adenine in RNA? (1)
Uracil (Thymine = DNA).
A DNA sample contains 23% adenine. What % will be cytosine? (1)
27%.
Which of these statements is not true about a gene in prokaryotes?
A. codes for the primary structure of a protein
B. codes for a functional RNA
C. contains introns
D. is coded by four bases - ATCG
C - Contains introns.
What are the two joined copies of a chromosome properly called? (1) A. sister chromosomes B. centromeres C. sister chromatids D. centrioles E. chromosomes
C - Sister chromatids.
What is the point where the two chromosome copies are joined called? (1) A. chromatid B. centriole C. centromere D. centrosome
B - Centriole.
What stage of the cell cycle involves the division of the cytoplasm? (1) A. telophase B. cytokineses C. anaphase D. G1 phase
B - Cytokineses.
What stage of the cell cycle involves the copying of DNA? (1) A. G2 phase B. prophase C. mitosis D. S phase
D - S phase
Which phase of meiosis involves the reduction of chromosome number from diploid to haploid? (1) A. telophase I B. prophase I C. metaphase II D. anaphase II
A - Telophase I.
What stage of the cell cycle involves the separation of the chromatids? (1) A. prophase B. anaphase C. metaphase D. telophase
B - Anaphase.
When does crossing over of sections of chromatids occur? (1) A. telophase I B. metaphase I C. anaphase II D. metaphase II
B - Metaphase I.
When does the nuclear envelope break down? (1) A. at the end of prophase B. it doesn't C. anaphase D. between metaphase and anaphase
A - At the end of prophase.
Which meiotic division is most similar to mitosis? (1)
A. Meiosis I
B. Meiosis II
B - Meiosis II.
An onion cell nucleus normally contains 12 chromosomes. In which stages of the cell cycle are there 24 chromatids? (1)
A. G1, anaphase, telophase, metaphase, prophase
B. G1, metaphase, prophase, anaphase
C. G1, end of S, metaphase, prophase, anaphase, telophase
D. G1, S, metaphase, anaphase, prophase
E. G2, anaphase, telophase, metaphase, prophase
F. G2, metaphase, prophase, anaphase
G. G2, end of S, metaphase, prophase, anaphase, telophase
H. G2, S, metaphase, anaphase, prophase
G - G2, end of S, metaphase, prophase, anaphase, telophase.
What small circular DNA structure in prokaryotes often contains genes for antibiotic resistance? (1)
Plasmid.
What kingdom has cell walls formed of peptidoglycan (murien)? (1) A. fungi B. plants C. protoctista D. prokaryotes E. animals
D - Prokaryotes.
What structure is found in both eukaryotic and prokaryotic cells? (1) A. nucleolus B. plasmids C. 70S ribosomes D. 80S ribosomes
C - 70S ribosomes.
What form of genetic material is found in viruses? (1)
A. DNA only
B. RNA only
C. DNA and RNA
B - RNA only.
Which of the following is not found in viruses? (1) A. attachment proteins B. DNA and RNA C. capsid D. lysosome
D - Lysosome.
What is the name of the stacks of membranes inside the chloroplasts? (1)
Thykaloids.
What is the function of the nucleolus? (1) A. protein synthesis B. ribosome synthesis C. post transcriptional modification D. RNA polymerase synthesis
B - Ribosome synthesis.
Why is the buffer used in cell fractionation and centrifugation chilled? (1)
A. prevent cell lysis
B. reduce digestive enzyme activity
C. prevent denaturation of proteins
D. prevent movement of water out of cell by osmosis
B - Reduce digestive enzyme activity.
