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Homework Answers
C & C page 181 #1-4
1. Give 3 reasons why specialized systems are necessary in large multicellular organisms.
Specialized systems are necessary in large multicellular organisms since 1. there is a division of
labor between cells, 2. many individual cells cannot work together without coordination and 3.
most of the cells are not in direct contact with the outside environment.
2. Arrange these terms in increasing order of complexity: cells, systems, organs, tissues,
organisms.
The terms in order of increasing complexity are cells, tissues, organs, systems, and organisms.
3. Can single cell from a system or a tissue? Explain your answer.
A single cell cannot form a system or a tissue since, by definition, these terms describe
collections of cells with a specialized function.
4. What limits the size of cells?
Cell size is limited by the ability of diffusion to transport adequate nutrients into the cell and to
remove waste from the cell.
RI page 182 #1-6, 9
1. Compare the differences and similarities of prokaryotic and eukaryotic cells?
Both prokaryotic and eukaryotic cells are surrounded by a plasma membrane and use
DNA to encode their genetic information. Eukaryotic cells have a membrane –enclosed
nucleus and other membrane-enclosed organelles. Their DNA is combined with protein
along the chromosomes. In contrast prokaryotes lack a nucleus and membraneenclosed organelles. Their DNA exists as a single chromosome without protein.
2. How do the walls of plants and bacterial cells differ? How are they similar?
Plant cell walls contain cellulose as a basic structural component. Bacterial cell walls
lack cellulose. Both cell walls provide a rigid enclosure for the cell.
3. How does the cytosol differ in prokaryotes and eukaryotes?
The cytosols of prokaryotes and eukaryotes differ in that the cytosol of eukaryotic cells
is compartmentalized into organelles that separated different area of metabolism and
increase efficiency.
4. What cell part specializes in packaging materials for export? Give an example.
The Golgi apparatus packages materials for export from the cell. Materials in the
plasma membrane can be packaged inside vesicles that bud off from the plasma
membrane.
5. List 3 cell parts found in both prokaryotes and eukaryotes.
The plasma membrane, ribosomes, and flagella are found in both prokaryotes and
eukaryotes.
6. Define unicellular, colonial and multicellular.
Unicellular means “one-celled,” multicellular means “many-celled” and colonial means
“a cluster of cells existing together without much division of labor.”
9. Explain the difference between tissues and organs?
A tissue is a specialized mass or layer of cells. Organs are collections of different tissues
that take on specific functions.