Transcript Lesson 12 Ch. 1 Review Q`s and A`s

Chap. 1 Review Q’s
p. 38 1 – 7, 9, 12 - 14
1. The two main ideas in the modern cell
theory are…
• All living things are composed of one or
more cells;
•All new cells come from cells that already
exist, (pre-existing).
2. Larger animals do not have larger cells than
smaller cells, just… More of them.
3. Plant and animal cell placed in a
concentrated salt solution…
• Will both shrivel/shrink due to water osmosing
out of the cells,
The water osmoses out because the
cytoplasm has a higher concentration
of water than the solution outside the
cells. Water osmoses from high to low.
4. True or false…
a. All living things are composed of cells: True
b. The light microscope allows scientists to view
cells, molecules, and atoms: False; not powerful enough to
see molecules!
c. It is easy to tell animal cells from plant cells, because
animal cells are always larger: False: animal cells are usually
smaller.
d. All cells are surrounded by a cell wall: False: animal
cells do not
have a cell wall.
4. True or False cont’d:
e. The nucleus is the control centre of the cell: True
f. Chloroplasts are found in plant cells, but not in
animal cells: True
g. Diffusion occurs when molecules move from an area
of low concentration, to an area of high concentration:
False - it’s the opposite: from high to low.
h. If an onion cell is placed in a concentrated salt
solution, water will move out of the cell: True - it will
osmose out of
the cell
5. A red blood cell bursts when placed
in a distilled, (pure) water.
The cell bursts because the pure water
osmoses into the cell. Without a cell wall
or contractile vacuole, there is nothing to
hold it together.
6. Identify as either plant or animal
cells tend to be smaller, and have less regular/more
cell: Animal
squiggly shapes, because they lack a cell wall for rigid support.
a. animal
c. plant
e. animal
b. plant
d. plant
f. animal
7. Why does the sugar move into the cell?
There is more sugar inside the cell in
B, because the sugar either
osmosed into the cell, or was
pulled in by the proteins lining the
pores. Sugar is needed by the
cell for energy.
There is less sugar in C
because it was used up by
the mitochondria to make
energy for the cell.
9. The cell is moving upwards and to the left.
The slide should be moved…
Also upwards and to the left, since what you see is
upside down and backwards. The cell is actually
swimming down and to the right, so to keep it in the
field of view, you must move it up and to the left.
12. Which is the size and shape of a muscle
cell? Explain
Picture C is most like a muscle cell, because
the long, cigar shape, gives it more surface
area compared to its volume, which is good
for exchanging nutrients and wastes.
13. Celery in coloured water
a. The student was trying to answer: how does Temperature affect
the speed of water rising up the stalk?
b. Hypothesis: if warmer water has more energy, then the dye should
rise higher in the celery sitting in hotter water.
c. Independent variable (the one you purposely change): Temperature
Dependent variable (the one that depends on what you changed):
Height of the coloured water.
d. Measure the rates of diffusion by measuring how high the coloured
water travelled.
e. The stalk in the 40 degree water would have the greatest movement of
dye, because the coloured water has more energy and therefore osmoses
more quickly.
f. Possible sources of error are not having the same size/shape
of celery sticks, the temperatures becoming the same (room
temperature), mixing up the pieces of celery from different
stalks, etc.
14. Criteria to judge whether something
is an organism:
• Made of cells
•reproduces, grows, repairs, (cell division)
•Requires energy
•Responds to the environment
•Lives, ages, dies, (life span)
•Produces wastes