Abiotic Factors
Name two abiotic factors, other than salt concentration, that affect the density of seawater.
Temperature and Pressure
State two features that are typical of all echinoderms.
Pentaradial symmetry and tube feet
This marine habitat is a major food source and helps stabilize the sand or substrate.
Seagrass beds
This is the chemical formula for calcium carbonate, used in marine bones and shells.
CaCO_3
This is the minimum number of marks needed to reach an "E" level pass.
21 Marks
This is the specific term for a concentrated solution of sodium chloride in water, often found in deep-sea pools.
Brine
Name the Kingdom and Phylum for a crown-of-thorns starfish.
Kingdom Animalia, Phylum Echinodermata
Beyond being a nursery, mangroves protect shorelines from this specific physical process.
Coastal erosion
Explain why the symbol for a chloride ion is written as Cl^-
t gains an electron from sodium to complete its outer shell
You should scan the test and answer these types of questions first to build confidence.
Easy Marks
State one abiotic factor that can specifically reduce the percentage cover of coral on a reef.
Temperature change/Salinity change/Hurricanes;
This structure is used by organisms like seaweed to attach themselves firmly to rocks.
Holdfast
Marine plants like seagrass act as this type of "sink" by absorbing CO_2
Carbon sink
At a high population density, Crown-of-Thorns starfish cause this to happen to coral diversity.
It reduces diversity
There are this many total "easy marks" available on the paper
28 Marks
Calculate the density of a $300.0 cm-3 brine sample with a mass of $358.2g
1.194g/cm-3
These air-filled structures allow some marine algae to float and maximize photosynthesis.
Air bladders
Name two economic (not ecological) benefits of healthy seagrass beds
Tourism and increased income for local populations
This type of relationship exists when hard coral decreases while algae percentage cover increases.
Inverse relationship (negative correlation)
To reach a "C" grade, you need all easy marks plus this percentage of the hard mark
25% (roughly 7 marks)
Describe the relationship between water temperature and the density of seawater.
As temperature increases, density decreases (Inverse relationship).
This is the genus and species name for the crown-of-thorns starfish.
Acanthaster planci.
List three distinct causes for the global loss of mangrove forests.
Over-harvesting, storm damage, pollution, or climate change
Explain how a low density of COTS can actually increase coral diversity.
They consume fast-growing corals, allowing space for slower-growing species to settle.
The amount of detail in your answer should always be linked to this feature of the question.
The number of marks allocated.