Chap. 1 Review Q’s 1 – 7, 9,

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 cells 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 cell: a. animal b. plant c. plant d. plant e. animal f. animal Animal cells tend to be smaller, and have less regular/more squiggly shapes, because they lack a cell wall for rigid support.

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