Past paper questions higher Flashcards
Cytoplasm
where many of the chemical reactions happen.
Nucleus
Contains DNA
Cell membrane
controls the movement of substances in and out of the cell.
Mitochondria
where most energy is released in respiration.
Ribosomes
where protein synthesis occurs.
Chloroplast
contains chlorophyll, which absorbs light energy for photosynthesis.
Cell wall
strengthens the cell and supports the plant.
Permanent vacuole
Filled with cell sap
calculate the magnification of an image
Magnification= size of image / real size of object
what are the risks of investigating with a light microscope.
Care must be taken when looking down the microscope if the illumination is too bright.
Care must be taken when using microscope stains.
Care must be taken when handling coverslips and microscope slides.
State the name of the part of the cell that is the site of respiration.
Mitochondria
Many exchange surfaces in living things have a large surface area.
What is an example of an exchange surface.
The villi in the digestive system
Communicable diseases, like the common cold, can infect organisms in different ways. Select the correct way in which many farmers believe tuberculosis infects their cows.
Vector
Explain why the potato pieces in the 0.4 mol/dm3 salt solution decreased in mass.
water moves out of cells / potato
by osmosis
(because) the solution in the
cells / potato is less
concentrated than outside
or
(because) the solution in the
cells / potato is more dilute than
outside
Which disease is caused by a fungus?
rose black spot
Give a reason for each of the following steps in the method.
1. A thin layer of onion epidermis is used.
help see individual cells
Give a reason for each of the following steps in the method.
2. Iodine solution is added to the onion epidermis.
to stain / see the parts of the cell
Give a reason for each of the following steps in the method.
3. The cover slip is lowered onto the onion epidermis at an angle.
to prevent / reduce air bubbles
two ways the student could improve the drawing of onion cells
any two from:
* include magnification / scale
* use continuous lines
or ensure no gaps in lines
* do not draw overlapping cells
* draw (wider) cell walls
* do not shade
* draw all the cells present
* draw correct cell shapes
* do not have gaps between
cells
* draw nuclei in correct location
* label cell part(s)
Give two ways onion cells would look different when seen using an electron
microscope.
(cell would) have more detail
Identify whether each defence is a chemical response or a physical response.
1.Thick, waxy layer on leaf surface
Physical
Identify whether each defence is a chemical response or a physical response.
2. Berries that are poisonous
chemical
Identify whether each defence is a chemical response or a physical response.
3. Bark on trees that falls off
physical
Explain why a tree might die if the roots of the tree are damaged.
- less absorption of water
o less water so lower rate of photosynthesis - less absorption of (named) ions / minerals
o fewer nitrates so fewer proteins made for growth - damage to phloem
o less transport of sugars to root cells - damage to xylem
o less water transported (to cells) - less anchorage
