The _______ was the first unifying principle of biology.
A. spontaneous generation theory
B. cell theory
C. germ theory of disease
D. theory of genetic determinism
E. law of Ohno
Answer choice B
DNA strands can be visualized using which of the following instruments?
A. Light microscope
B. Electron microscope
C. Dissecting microscope
D. Centrifuge
E. Thermocycler
Answer choice A
The organelles and biomolecules present in homogenized cells can be separated by
centrifugation. Which of the following would be found at the top of a centrifugation gradient?
A. golgi
B. mitochondria
C. nuclei
D. ribosomes
E. ATP molecules
Answer choice C
Prokaryotes
A. are surrounded by a plasma membrane.
B. have a nucleus.
C. do not have ribosomes.
D. have a cell wall similar in composition to that of plant cells.
E. are larger than eukaryotic cells.
Answer choice A
The proteins that make up the cytoskeleton of bacteria are similar to _______ in eukaryotic cells.
A. proteases
B. sterols
C. actin
D. transcription factors
E. telomerases
Answer choice C
Which of the following statements about prokaryotes is false?
A. Prokaryotes comprise a single domain.
B. Prokaryotes are the most numerous organisms on Earth.
Prokaryotes have evolved many different mechanisms of deriving energy from the
C.
environment.
D. A very small proportion of prokaryotes are pathogenic.
E. Some prokaryotes can live in extreme environments.
Answer choice A
Which of the following characteristics is not shared by Archaea, Bacteria, and Eukarya?
A. Semiconservative replication of DNA
B. Plasma membranes
C. Ribosomes
D. Cytoskeleton
E. Glycolysis
Answer choice E
The first step towards a eukaryotic cell was
A. mitochondria.
B. a cytoskeleton.
C. a flexible cell surface.
D. a cell wall.
E. endosymbiosis.
Answer choice D
A chloroplast that is the result of secondary endosymbiosis would have _______ membrane(s).
A. One
B. Two
C. three
D. four
E. No
Answer choice C