General Biology 1 - BSC 1010C - Chapter 6: A Tour of the
Cell Questions With Complete Solutions
Are plant and animal cells prokaryotic or eukaryotic? What are
some major differences between plant and animal cells? Correct
Answers Plant and animal cells are both eukaryotic. Plant cells
have a cell wall, chloroplasts, plasmodesmata, and a central
vacuole that holds water and nutrients; many also move via
cytoplasm streaming. Animal cells do not have cell walls, but
they have lysosomes, centrosomes, and centrioles; they also use
flagella or cilia for transportation.
Cell junctions Correct Answers Contact points between the
plasma membranes of tissue cells.
Cell wall Correct Answers A protective layer external to the
plasma membrane in the cells of plants, prokaryotes, fungi, and
some protists. It protects the cell, maintains its shape, and
prevents excessive water uptake. Polysaccharides such as
cellulose, chitin, and peptidoglycan are important structural
components of cell walls.
Centrosome and centrioles Correct Answers The centrosome is
a structure present in the cytoplasm of animal cells that
functions as a microtubule-organizing center and is important
during cell division; it has two centrioles, composed of cylinders
of microtubule triplets arranged in a "9 + 0" pattern.
Chloroplast Correct Answers An organelle found in plants and
photosynthetic protists that absorbs sunlight and uses it to drive
the synthesis of organic compounds from carbon dioxide and
, water. Chloroplasts contain thylakoids, membranous sacs, which
are stacked together in granum, as well as storms, the internal
fluid of the organelle.
Cytoskeleton Correct Answers A network of microtubules,
microfilaments, and intermediate filaments that branch
throughout the cytoplasm and serve a variety of mechanical and
transport functions. It organizes structures and activities in the
cell.
Describe the technique of cell fractionation and explain how it
was useful for determining the molecular composition of cells.
Correct Answers Cell fractionation is the disruption of a cell
and separation of its parts by centrifugation at successively
higher speeds. This technique enables researchers to prepare
specific cell components in bulk and identify their functions. For
example, on one of the cell fractions, biochemical tests showed
the presence of enzymes involved in cellular respiration, while
electron microscopy revealed large numbers of mitochondria.
These data helped biologists determine that mitochondria are the
sites of cellular respiration.
Endoplasmic reticulum (ER) Correct Answers An extensive
membranous network in eukaryotic cells, continuous with the
outer nuclear membrane and composed of ribosome-studded
(rough) and ribosome-free (smooth) regions.
Extracellular matrix (ECM) Correct Answers The meshwork
surrounding animal cells, consisting of glycoproteins,
polysaccharides, and proteoglycans synthesized and secreted by
Cell Questions With Complete Solutions
Are plant and animal cells prokaryotic or eukaryotic? What are
some major differences between plant and animal cells? Correct
Answers Plant and animal cells are both eukaryotic. Plant cells
have a cell wall, chloroplasts, plasmodesmata, and a central
vacuole that holds water and nutrients; many also move via
cytoplasm streaming. Animal cells do not have cell walls, but
they have lysosomes, centrosomes, and centrioles; they also use
flagella or cilia for transportation.
Cell junctions Correct Answers Contact points between the
plasma membranes of tissue cells.
Cell wall Correct Answers A protective layer external to the
plasma membrane in the cells of plants, prokaryotes, fungi, and
some protists. It protects the cell, maintains its shape, and
prevents excessive water uptake. Polysaccharides such as
cellulose, chitin, and peptidoglycan are important structural
components of cell walls.
Centrosome and centrioles Correct Answers The centrosome is
a structure present in the cytoplasm of animal cells that
functions as a microtubule-organizing center and is important
during cell division; it has two centrioles, composed of cylinders
of microtubule triplets arranged in a "9 + 0" pattern.
Chloroplast Correct Answers An organelle found in plants and
photosynthetic protists that absorbs sunlight and uses it to drive
the synthesis of organic compounds from carbon dioxide and
, water. Chloroplasts contain thylakoids, membranous sacs, which
are stacked together in granum, as well as storms, the internal
fluid of the organelle.
Cytoskeleton Correct Answers A network of microtubules,
microfilaments, and intermediate filaments that branch
throughout the cytoplasm and serve a variety of mechanical and
transport functions. It organizes structures and activities in the
cell.
Describe the technique of cell fractionation and explain how it
was useful for determining the molecular composition of cells.
Correct Answers Cell fractionation is the disruption of a cell
and separation of its parts by centrifugation at successively
higher speeds. This technique enables researchers to prepare
specific cell components in bulk and identify their functions. For
example, on one of the cell fractions, biochemical tests showed
the presence of enzymes involved in cellular respiration, while
electron microscopy revealed large numbers of mitochondria.
These data helped biologists determine that mitochondria are the
sites of cellular respiration.
Endoplasmic reticulum (ER) Correct Answers An extensive
membranous network in eukaryotic cells, continuous with the
outer nuclear membrane and composed of ribosome-studded
(rough) and ribosome-free (smooth) regions.
Extracellular matrix (ECM) Correct Answers The meshwork
surrounding animal cells, consisting of glycoproteins,
polysaccharides, and proteoglycans synthesized and secreted by
