Essential Cell Biology 5th edition

Questions
37
• Free-living, single-celled eukaryotic microorganisms are complex
cells that, in some cases, can swim, mate, hunt, and devour other
microorganisms.
• Animals, plants, and some fungi are multicellular organisms that consist
of diverse eukaryotic cell types, all derived from a single fertilized
egg cell; the number of such cells cooperating to form a large, multicellular
organism such as a human runs into thousands of billions.
• Biologists have chosen a small number of model organisms to study
intensely, including the bacterium E. coli, brewer’s yeast, a nematode
worm, a fly, a small plant, a fish, mice, and humans themselves.
• The human genome has about 19,000 protein-coding genes, which is
about five times as many as E. coli and about 5000 more than the fly.
KEY TERMS
archaeon endoplasmic reticulum model organism
bacterium eukaryote nucleus
cell evolution organelle
chloroplast fluorescence microscope photosynthesis
chromosome genome plasma membrane
cytoplasm Golgi apparatus prokaryote
cytoskeleton homologous protein
cytosol micrometer protozoan
DNA microscope ribosome
electron microscope mitochondrion RNA
QUESTIONS
QUESTION 1–8
By now you should be familiar with the following cell
components. Briefly define what they are and what function
they provide for cells.
A. cytosol
B. cytoplasm
C. mitochondria
D. nucleus
E. chloroplasts
F. lysosomes
G. chromosomes
H. Golgi apparatus
I. peroxisomes
J. plasma membrane
K. endoplasmic reticulum
L. cytoskeleton
M. ribosome
QUESTION 1–9
Which of the following statements are correct? Explain your
answers.
A. The hereditary information of a cell is passed on by its
proteins.
B. Bacterial DNA is found in the cytoplasm.
C. Plants are composed of prokaryotic cells.
D. With the exception of egg and sperm cells, all of the
nucleated cells within a single multicellular organism have
the same number of chromosomes.
E. The cytosol includes membrane-enclosed organelles
such as lysosomes.
F. The nucleus and a mitochondrion are each surrounded
by a double membrane.
G. Protozoans are complex organisms with a set of
specialized cells that form tissues such as flagella,
mouthparts, stinging darts, and leglike appendages.
H. Lysosomes and peroxisomes are the sites of degradation
of unwanted materials.