Question

1. what does nitrogen fixation ultimately add to the sea?

a.) carbon
b.) nitrogen
c.) oxygen
d.) carbon dioxide

1. some bioluminescent animals have organs that contain colonies of luminescent bacteria. these

organs are called
a.) nerve nets
b.) lighted cavities
c.) photophores
d.) illuminadae

1. which of the following best describes a lichen?

a.) parasitic relationship between a virus and phytoplankton
b.) predator-prey relationship between a carnivorous microbe & an herbivorous microbe
c.) symbiotic relationship between kelp (brown algae) and a bioluminescent organism
d.) mutualistic relationship between a fungus and an alga

1. red tides (harmful algal blooms that produce toxins & kill fish) are caused by:

a.) dinoflagellates
b.) ciliates
c.) diatoms
d.) lichens

1. many of the microbes and algae weve discussed in this unit are considered benthic. what does

benthic refer to?
a.) the oceans surface
b.) the sea floor
c.) cold temperature loving
d.) salt tolerant

1. what factor of the ocean affects the distribution of red, brown & green algae?

a.) density
b.) salinity
c.) temperature
d.) dissolved oxygen

1. algae (also referred to as seaweed) are not considered plants because:

a.) they are multicellular
b.) they have other pigment colors besides green
c.) they are chemosynthetic instead of photosynthetic
d.) they dont have roots, stems or leaves

Explanation:

• Question 6: Nitrogen fixation is the process of converting nitrogen gas (\(N_2\)) into forms like ammonia (\(NH_3\)) that can be used by organisms. In the context of the sea, it ultimately adds nitrogen.
• Question 7: Photophores are the organs in some bioluminescent animals that contain colonies of luminescent bacteria.
• Question 8: A lichen is a mutualistic relationship between a fungus and an alga. The fungus provides a structure and protection, while the alga provides food through photosynthesis.
• Question 9: Red tides are caused by dinoflagellates. These are a type of algae that can produce toxins.
• Question 10: Benthic refers to the sea floor. Organisms that are benthic live on or near the bottom of the ocean.
• Question 11: Temperature affects the distribution of red, brown, and green algae. Different algae have different temperature preferences.
• Question 12: Algae are not considered plants because they don't have roots, stems, or leaves.

Answer:

1. B. Nitrogen
2. C. Photophores
3. D. Mutualistic relationship between a fungus and an alga
4. A. Dinoflagellates
5. B. The Sea Floor
6. C. Temperature
7. D. They don’t have roots, stems or leaves