MARINE SCIENCE LATEST EXAM PAPER
QUESTIONS AND ANSWERS SURE A+
✔✔three methods used for the reconstruction of the history of coral reefs - ✔✔1. carbon
dating-the process of carbon dating:
-it is a radioactive isotope of carbon which is produced in the upper atmosphere by
cosmic radiation. a very small amount of CO2 contains C14
-during photosynthesis-plants absorb C14 and then animals consume plants
-when an organism dies it stops taking in C14. at the time of death, C12 and C14 are
the same for tall living organisms.
-but, the C14 starts to decay. C14 has a half-life of 5700 years.
-by looking at the ratio of C12 to C14 in the sample and comparing it to the ratio in a
living organism, it is possible to determine the age of a formerly living things fairly
precisely
2. coral drilling/sampling-data showed: age of corals increased with depth
3. geomorphological analysis-the geomorphology of reefs largely reflects two main
variables: relative sea level rise and the nature of the underlying substrate
-soils on atolls relatively you ng around 3500 years old
-matches dates of post-glacial period
-supports hypothesis that sea level fall exposed reef platforms
✔✔coral reef - ✔✔-high biodiversity due to high productivity
-can support many different secondary consumers/predators
, -long food chains possible
-relatively stable environment
-many different niches
✔✔corals and zooxanthellae - ✔✔-corals are an animal
-zooxanthellae are a single-celled algae/plant which live within the tissues of the coral.
contain chlorophyll so they can photosynthesize
-mutualistic/symbiotic relationship
-zooxanthellae provide nutrients for coral animals
-corals provide a large surface area for the zoos. growth gives the zoos. conditions for
maxim, absorption of light
-products of digestion by corals provide nutrients for zoox.
✔✔what do corals need for growth? - ✔✔-light-clear water, low sedimentation/low silt
level
1. allows zooxanthellae to photosynthesize
2. allows coral polyps to feed
-shallow and warm water
✔✔how does sedimentation reduce coral growth? - ✔✔-sedimentation/silt covers coral
-reduces light penetration
-inhibits/reduces photosynthesis
-reduced photosynthesis reduces coral growth
✔✔what happens to corals if seawater becomes acidic? - ✔✔-too much carbon dioxide
leads to acidic water-causes coral skeletons to dissolve
-coral bleaching-high water temp. kills zooxanthellae-coral bleaches-coral dies
✔✔artificial reefs - ✔✔a. common materials used: concrete and steel. very important
that the material is non-toxi. so it does not harm marines organism because toxic
material will dissolve in water nor enter the food chain
b. benefits: boosts economy by attracting tourists for: fishing, snorkeling/diving, more
tourists=more local spending
provides suitable substrate for coral attachment; promoting higher biodiversity
protect shores
✔✔plate tectonic theory - ✔✔do not confuse with continental drift. cont drift was in 1912
and plate ted was in the 1960s. cont drift-continents drift over ocean floor. plate ted-
crust broken into plates which float on the underlying layer
✔✔describing plate tectonic theory - ✔✔-earth's crust/lithosphere is made of plates
-continents lie on plates
-plates are float/moving slowly on top of asthenosphere
-plates meet at boundaries; convergent, divergent, and volcanic eruptions
-plates move due to convection currents in the asthenosphere
QUESTIONS AND ANSWERS SURE A+
✔✔three methods used for the reconstruction of the history of coral reefs - ✔✔1. carbon
dating-the process of carbon dating:
-it is a radioactive isotope of carbon which is produced in the upper atmosphere by
cosmic radiation. a very small amount of CO2 contains C14
-during photosynthesis-plants absorb C14 and then animals consume plants
-when an organism dies it stops taking in C14. at the time of death, C12 and C14 are
the same for tall living organisms.
-but, the C14 starts to decay. C14 has a half-life of 5700 years.
-by looking at the ratio of C12 to C14 in the sample and comparing it to the ratio in a
living organism, it is possible to determine the age of a formerly living things fairly
precisely
2. coral drilling/sampling-data showed: age of corals increased with depth
3. geomorphological analysis-the geomorphology of reefs largely reflects two main
variables: relative sea level rise and the nature of the underlying substrate
-soils on atolls relatively you ng around 3500 years old
-matches dates of post-glacial period
-supports hypothesis that sea level fall exposed reef platforms
✔✔coral reef - ✔✔-high biodiversity due to high productivity
-can support many different secondary consumers/predators
, -long food chains possible
-relatively stable environment
-many different niches
✔✔corals and zooxanthellae - ✔✔-corals are an animal
-zooxanthellae are a single-celled algae/plant which live within the tissues of the coral.
contain chlorophyll so they can photosynthesize
-mutualistic/symbiotic relationship
-zooxanthellae provide nutrients for coral animals
-corals provide a large surface area for the zoos. growth gives the zoos. conditions for
maxim, absorption of light
-products of digestion by corals provide nutrients for zoox.
✔✔what do corals need for growth? - ✔✔-light-clear water, low sedimentation/low silt
level
1. allows zooxanthellae to photosynthesize
2. allows coral polyps to feed
-shallow and warm water
✔✔how does sedimentation reduce coral growth? - ✔✔-sedimentation/silt covers coral
-reduces light penetration
-inhibits/reduces photosynthesis
-reduced photosynthesis reduces coral growth
✔✔what happens to corals if seawater becomes acidic? - ✔✔-too much carbon dioxide
leads to acidic water-causes coral skeletons to dissolve
-coral bleaching-high water temp. kills zooxanthellae-coral bleaches-coral dies
✔✔artificial reefs - ✔✔a. common materials used: concrete and steel. very important
that the material is non-toxi. so it does not harm marines organism because toxic
material will dissolve in water nor enter the food chain
b. benefits: boosts economy by attracting tourists for: fishing, snorkeling/diving, more
tourists=more local spending
provides suitable substrate for coral attachment; promoting higher biodiversity
protect shores
✔✔plate tectonic theory - ✔✔do not confuse with continental drift. cont drift was in 1912
and plate ted was in the 1960s. cont drift-continents drift over ocean floor. plate ted-
crust broken into plates which float on the underlying layer
✔✔describing plate tectonic theory - ✔✔-earth's crust/lithosphere is made of plates
-continents lie on plates
-plates are float/moving slowly on top of asthenosphere
-plates meet at boundaries; convergent, divergent, and volcanic eruptions
-plates move due to convection currents in the asthenosphere
