week 7 - ocean food chains

Question 1

plankton

Answer 1

organisms that drift within the water column of the open ocean

Question 2

two types of plankton

Answer 2

phytoplankton and zooplankton

Question 3

pelagic zone

Answer 3

area of water that is not near the bottom, or shore, or a body of water
- organisms here cant swim or have limited swimming ability

Question 4

benthic zone

Answer 4

area associated directly with the seafloor

Question 5

photic zone

Answer 5

where light exists, depth is variable
- includes the euphotic and dysphotic zone

Question 6

euphotic zone

Answer 6

region from surface to dysphotic zone where photosynthesis is larger than respiration

Question 7

dysphotic zone

Answer 7

region where light still exists but where photosynthesis is smaller than respiration (or even absent where light is too weak)

Question 8

aphotic zone

Answer 8

completely dark, no photosynthesis at all

Question 9

epifaunal

Answer 9

organisms that live on the seafloor sediment
- those attached to a fixed structure cant be mobile but others can

Question 10

infaunal

Answer 10

benthic organisms that live within the sediment

Question 11

phytoplankton

Answer 11

primary producers of the marine ecosystem and are the first link in the marine food web

Question 12

different types of phytoplankton

Answer 12

1. diatoms
   - produce a silica mineralized cell wall and rely on surface waters to keep them in the euphotic zone
2. coccoid cyanobacteria
   - blue green algae, very abundant
3. dinoflaggelates
   - bioluminescent, make red tides
4. coccolithophores
   - calcareous plates or disks that can be shed

Question 13

zooplankton

Answer 13

single celled protozoan and multicellular animal species
- occupy the primary and secondary consumer trophic levels of the marine food web

Question 14

types of zooplankton

Answer 14

1. copepods
   - small crustaceans that ascend to surface waters at night to feed and descend to avoid predators
2. krill
   - shrimp like crustaceans, can swim against weak current
3. radiolarians
   - produce silica skeletons, stay afloat with low density fats and spiny exteriors that increase surface area and keep them from sinking
4. foraminiferans
   - produce a spiral or globular calcareous shell, capture food with a cytoplasm net
5. macroplankton
   - includes krill pteropods and jellyfish, bigger

Question 15

three levels of the biotic community

Answer 15

producers, consumers, and decomposers

Question 16

producers - autotrophs

Answer 16

produce organic compounds by photosynthesis from inorganic compounds and external inorganic sources of energy

Question 17

consumers - heterotrophs

Answer 17

feed off of autotrophs or other heterotrophs for energy and organic carbon compounds for growth and development

Question 18

decomposers - saprotrophs

Answer 18

form of heterotrophs that are the decomposers and recyclers in the food chain
- obtain energy from wasters or dead organisms and return nutrients to the physical environment
ex. worms

Question 19

food chain

Answer 19

simple arrangment of organisms according to the order of predation
- only shows single possible way between organisms

Question 20

food web

Answer 20

the complex network of interactions among organisms

Question 21

primary productivity

Answer 21

rate of synthesis of organic matter from inorganic materials by photosynthesis
- expressed in grams of carbon bound into organic material per square meter of ocean surfaec area per year

Question 22

formula for photosynthesis

Answer 22

6H20 + 6CO2 + sunlight + C6H1206 + 6O2

Question 23

formula for respiration

Answer 23

C6H12O6 + 6O2 + 6H2O + metabolic energy

Question 24

two factors that limit phytoplankton growth

Answer 24

1. availability of sunlight and nutrients

Question 25

main limiting nutrients required in primary productivity

Answer 25

nitrogen and phosphorus

Question 26

readily available nutrients in primary productivity

Answer 26

calcium, sodium, magnesium, water, CO2 and CA2+

Question 27

what are micronutrients

Answer 27

essential nutrients required by organisms in much lower concentrations

iron copper and seleniums

• only small amounts needed for life

Question 28

photosynthesis

Answer 28

the process by which organisms use chlorophyll to absorb energy from sunlight and convert CO2 and H2O into glucose and O2

Question 29

gross primary product (GPP)

Answer 29

total amount of photosynthetic production

Question 30

respiration

Answer 30

process that consumes oxygen

Question 31

net productivity

Answer 31

total photosynthesis - respiration

Question 32

respiration in formula

Answer 32

gross productivity - net productivity

Question 33

biological pump

Answer 33

exports photosynthetic products (organic carbon) from the euphotic zone to the deep ocean
- zooplankton feed on phytoplankton
- nutrients are transferred through fecal pellets in process called egestion