Essential Exam Questions Flashcards
(Arteries vs veins) Question: State the ways in which the structure of an artery differs from the structure of a vein.
Arties have..
- Thicker Walls
- More elastic tissue
- A smaller lumen
- No valves, but veins have valves
Make sure not to mention “They have” instead specify ie “Arties have”
(Gas Exchange) Question: Explain how human lung tissue allows efficient gas exchange
- The alveoli provide a large surface area
- Alveoli walls are one cell thick for a short diffusion pathway
- Alveoli walls are moist for gases to dissolve
- Capillary wall is only one cell thick for a short diffusion pathway
- The flowing blood maintains a concentration gradient
(Absorption in the small intestine) Question: Explain how the structure of the small intestine is adapted for efficient exchange of substances
- Villi provide a large surface area
- Villi have thin walls for a short diffusion pathway
- Villi have many capillaries to absorb glucose
- The blood supply maintains a diffusion gradient
- The lacteals absorb fatty acids and glycerol
- And are long to give a large surface area
(Genetically Modified Bacteria) Question: Describe the stages that are used to genetically modify a bacterium that is able to manufacture insulin
- Isolate the bacteria plasmid
- Plasmids are vectors
- Open the plasmid using a speciic restriction enzyme
- Extract the human gene [for insulin]
- Using the same restriction enzyme
- Join the gene with the plasmid using ligase
- Forming a recombinant plasmid (these plasmids are then re-inserted into the bacteria)
Design an investigation to find out if the colour of light affects the amount of fruit produced by a plant
C - Using red, blue, yellow and green lights
O - Grow tomata plants of the same age under each light
R - Grow 5 plants under each colour
M - Record the mass of tomatoes produced per plant
M2 - In one month
S - Use the same light intenstity for all plants
S2 - Give them each an equal volume of water
A student conducted an experiment to find out how the type of light bulb affects the mass of fruit produced by a plant
- Incandescent
- Fluorescent
- LED
Give the; Dependent Variable, the Independent variable, and two variables that should be controlled
The dependent variable
- Mass of Fruit
The independent variable
- Type of light bulb
Two variables that should be controlled
- Temperature of the environment
- Light intensity
(Make sure to never be vague/ambiguous)
A student wanted to compare the amount of starch in different liquid food samples.
- Add 3cm3 of three liquid samples to test tubes.
- Have three repeats for each sample
- Add 2 drops of iodine solution to each test tube.
- Compare the intensity of the colour change on a spotting tile.
Give 2 reasons why her results were reliable
- She used 3 test tubes for each sample giving three repeats
- She used the same volume of food samples for each test
