For the following definitions, provide the correct term.
1. A genetically based change in the characteristics of a
population over time.
[evolution]
2. Channel that connects the cytoplasm of two cells in
plants.
[plasmodesmata]
Answer the following questions.
3. List two functions of the Golgi apparatus
[receives products/modifies products/ships
products/stores products/manufactures
macromolecules]
4. What benefit does the mitochondria gain by having
infoldings in its inner membrane?
[Increased surface area for absorption]
For the following pairs of terms provide a concise
definition for each that will clearly distinguish between
the two terms. Be sure to include how the two terms are
related to one another.
5. microtubules / microfilaments
• [Both are internal structural support components of cells
that can be assembled & disassembled where needed in
the cell. Microtubules are larger and hollow and are
used to resist compression forces. Microfilaments are
smaller and solid and used to resist tension forces.]
Section 2. Short Answer.
Answer the following questions.
6. Many proteins get made in one type of cell and then get
exported for use in another type of cell. Describe the
route this type of protein would take, beginning with
where it was synthesized, what organelles it travels
through and ending with how the protein is exported from
the cell.
[Proteins for secretion are made by ribosomes attached
to the rough ER. They are packaged in a transport
vesicle by the ER and moved to the Golgi apparatus.
The GA modifies the proteins, wraps them in a transport
vesicle and sends them to the plasma membrane. The
transport vesicle fuses with the plasma membrane, and
the proteins are exported from the cell]
7. Most aspen trees reproduce asexually, which means that all of
the trees within one population are genetically identical
(clones). In a population of aspen clones, will the trees evolve
through natural selection? Why or why not?
[No, the trees will not evolve through natural selection. In order
for natural selection to occur, their must be genetic variation
within a population for the selection pressure to act on. The
aspen trees are clones (genetically identical), so there is no
variation, so no evolution by natural selection. (You can also
answer yes if you make a clear argument for the fact that
mutations do arise within populations, that would lead to
genetic variation – more on that when we cover evolution in
greater detail)]