how well a microscope distinguishes between 2 points that are close together.
how much larger the image is than the sample you are looking at.
how detailed the image is.
7. channel proteins are shaped so that a specific molecule can fit into them at the membrane surface. when the specific molecule fits, the protein changes shape to allow the molecule through to the other side.
False
True
8. Facilitated diffusion is the passive movement of molecules across membranes, down their concentration gradient, which is aided by carrier protein molecules.
None of the above
True
the movement of molecules down a concentration gradient, from an area of high concentration, to an area of low concentration.
the movement of water molecules from a region of higher water potential, to a region of lower water potential, across a partially permeable membrane
the movement of molecules against it's concentration gradient, using energy in the form of ATP, and transport proteins
9. what is the relationship between actual size, magnification and image size?
actual size = image size/magnification
actual size = magnification/image size
image size = magnification/actual size
magnification = actual size/image size
10. Define cytoskeleton?
the network of protein fibres found within cells that gives structure and shape to the cell, and also moves organelles around inside cells
the network of lipid fibres found within cells that gives structure and shape to the cell, and also moves organelles around inside cells
the network of protein fibres on the outside of cells that gives structure and shape to the cell, and also moves organelles around
the network of carbohydrate fibres found within cells that gives structure and shape to the cell, and also moves organelles around inside cells
11. what is the resolution and magnification of a light microscope?
resolution = 0.1nm, magnification = *100,000
resolution = 0.7nm, magnification = *7000
resolution = 200nm, magnification = *1500
resolution = 250nm, magnification = *500,000
12. what is the effect of a isotonic solution on a plant and animal cell?
net movement of water is into the cell, causing the cell to become turgid
water molecules move into and out of the cell in equal amounts, resulting in no changes to the cell.
net movement of water is out of the cell, causing it to become flaccid, and the cytoplasm to pull away from the cell wall, so that it is plasmolysed
net movement of water molecules is into the cell, causing it to burst.
13. Define Active Transport
the movement of molecules down a concentration gradient, from an area of high concentration, to an area of low concentration.
the movement of molecules against it's concentration gradient, using energy in the form of ATP, and transport proteins
the passive movement of molecules across membranes, down their concentration gradient, which is aided by carrier protein molecules.
the movement of water molecules from a region of higher water potential, to a region of lower water potential, across a partially permeable membrane
14. centrioles take part in cell division. They form fibres, known as the spindle, which moves chromosomes during nuclear division.
True
False
15. what is cell signalling?
the communication between cells using a hormone and a complementary receptor site that will bring about a change in other cells
the communication between cells using a neurotransmitter and a complementary receptor site that will bring about a change in other cells
the name of the hormone that cells use to communicate with other cells or organelles
the changes that a cell experiences as a result of another cells actions
16. what is the effect of a hypertonic solution on a plant cell?
net movement of water is out of the cell, causing it to shrink
net movement of water is out of the cell, causing it to become flaccid, and the cytoplasm to pull away from the cell wall, so that it is plasmolysed
water molecules move into and out of the cell in equal amounts, resulting in no changes to the cell.
net movement of water molecules is into the cell, causing it to burst.
17. In what process, do the chromatids uncoil and become chromosomes, and a new nuclear envelope form around each group of chromosomes, forming 2 new nuclei.
Metaphase
Cytokinesis
Telophase
Interphase
18. Define Osmosis
the movement of water molecules from a region of higher water potential, to a region of lower water potential, across a partially permeable membrane
the movement of molecules against it's concentration gradient, using energy in the form of ATP, and transport proteins
the movement of molecules down a concentration gradient, from an area of high concentration, to an area of low concentration.
the passive movement of molecules across membranes, down their concentration gradient, which is aided by carrier protein molecules.
19. in Anaphase the centromeres divide, separating each pair of sister chromatids. The spindle contracts, pulling the chromatids to opposite ends of the cell
True
False
20. what is the role of lysosomes?
they are involved in protein synthesis
they are spherical discs surrounded by a single membrane
they contain digestive enzymes, which break down materials
