clueless Flashcards
(22 cards)
What is the role of accessory pigments in light harvesting?
They absorb a range of light wavelengths and transfer energy to chlorophyll a in the reaction centre.
Where does light harvesting occur?
In the thylakoid membranes of chloroplasts.
What is produced in the light-dependent reactions for use in the Calvin Cycle?
ATP and NADPH.
Which mineral ion is essential for chlorophyll synthesis?
Magnesium (Mg²⁺).
What is a symptom of nitrate deficiency in plants?
Stunted growth and yellowing of older leaves.
How do you estimate bacterial population size using the viable count method?
Use serial dilutions, plate a known volume, count colonies, and multiply by dilution factor.
What does CFU stand for?
Colony-forming units.
What did Gause’s experiment with Paramecium demonstrate?
Competitive exclusion principle.
What causes eutrophication?
Excess nutrients from fertilisers leading to algal blooms and oxygen depletion.
Name one method to reduce eutrophication.
Use buffer strips or low-nutrient fertilisers.
What is in situ conservation?
Protecting species in their natural habitat.
What is ex situ conservation?
Conservation outside the natural habitat, like zoos or seed banks.
What are planetary boundaries?
Limits within which humanity can safely operate to avoid environmental degradation.
Name three planetary boundaries that have been transgressed.
Climate change, biodiversity loss, nitrogen cycle.
What is the resting potential of a neurone?
-70mV.
What ion movement causes depolarisation?
Influx of Na⁺ ions.
What happens during repolarisation?
K⁺ ions leave the neurone.
Why is the refractory period important?
Prevents backward conduction of the action potential.
What is the function of the myelin sheath?
Insulates axons and speeds up impulse conduction via saltatory conduction.
What is the difference between the sympathetic and parasympathetic nervous systems?
Sympathetic: fight or flight; Parasympathetic: rest and digest.
Symptoms if myelin sheath is damaged
- Weakness in limbs or general fatigue - Slower or blocked nerve impulses.
- Loss of coordination - affect motor control
