Marine Bio Unit 2 Flashcards
How are archaea similar and different from bacteria?
Similarities: Both are prokaryotes with no true nucleus or membrane-bound organelles.
Differences: Archaea have different lipid structures in their membranes and lack peptidoglycan in their cell walls. Genetically, archaea are more closely related to eukaryotes.
What is the mode of nutrition for photoautotrophic bacteria?
Photoautotrophic bacteria use light energy to convert carbon dioxide into organic compounds via photosynthesis.
What is the mode of nutrition for chemoautotrophic bacteria?
Chemoautotrophic bacteria obtain energy from chemical reactions, such as oxidizing sulfur or nitrogen compounds.
What is the mode of nutrition for heterotrophic bacteria?
Heterotrophic bacteria consume organic matter and break it down via respiration or fermentation.
What is the function of the bacterial cell wall?
The bacterial cell wall provides structural integrity and protection, preventing the cell from bursting in hypotonic environments.
How do cyanobacteria get their nutrition?
Cyanobacteria are photoautotrophs that use sunlight to perform photosynthesis and fix nitrogen into usable forms.
What is a stromatolite and what is its relationship to cyanobacteria?
A stromatolite is a layered, calcareous structure formed by cyanobacteria. These structures are among the oldest known fossils.
Why are decay bacteria vital to life on Earth?
Decay bacteria decompose dead matter, recycling nutrients back into the ecosystem, which is essential for nutrient cycling.
What kinds of environments do archaea live in?
Archaea live in extreme environments like hot springs, highly saline waters, and deep-sea vents, as well as more common marine environments like ocean sediments.
What is a producer?
A producer is an organism that creates its own food from inorganic sources, such as sunlight (photoautotrophs) or chemicals (chemoautotrophs).
Why is nitrogen fixation important?
Nitrogen fixation converts atmospheric nitrogen into ammonia, making nitrogen available for use by primary producers to build essential molecules like proteins.
Why are algae not considered plants?
Algae lack specialized tissues like roots, stems, and leaves, and have different reproductive cycles and cellular structures compared to plants.
What are the key differences between radiolarians and foraminifera?
Radiolarians: Have silica-based skeletons and use pseudopodia to capture prey.
Foraminifera: Build calcium carbonate shells and feed on detritus.
What are the key differences between diatoms and dinoflagellates?
Diatoms: Have silica-based frustules and are major primary producers.
Dinoflagellates: Have cellulose plates, two flagella, and some cause harmful algal blooms (red tides).
What is algin, which seaweed does it come from, and how is it harvested?
Algin, used in food, cosmetics, and medicine, comes from brown algae like kelp (Laminaria and Macrocystis). It is harvested sustainably from seaweed farms.
What are carrageenan and agar, and which seaweed do they come from?
Carrageenan, used in dairy products, and agar, used in food and labs, both come from red algae (Chondrus, Gelidium).
What is the environmental benefit of biofuels from marine algae?
Biofuels from algae reduce CO₂ and use seawater, helping fight climate change without using farmland.
What are seagrasses, salt marsh plants, and mangroves?
Seagrasses are underwater plants like eelgrass. Salt marsh plants grow in salty areas, and mangroves are trees in tropical tidal zones. They protect coastlines and provide habitats.
What role do seaweeds play in the ocean?
Seaweeds provide food and habitat, stabilize sediments, produce oxygen, and absorb CO₂.
What is the role of eelgrass in the ocean?
Eelgrass creates underwater meadows that provide shelter and food for marine life while stabilizing sediments.
How are eelgrass and surfgrass habitats different?
Eelgrass grows in shallow, protected waters like bays, while surfgrass thrives in rocky, wave-exposed coasts. Eelgrass inhabits oxygen-poor sediments, while surfgrass can be exposed during low tides
What are the functions of the holdfast, thallus, stipe, pneumatocyst, and blade in seaweed?
- Holdfast: Anchors the seaweed.
- Thallus: The body of the seaweed.
- Stipe: Supports the blades.
- Pneumatocyst: Helps the seaweed float.
- Blade: Photosynthesis happens here.
What are the division names of green, brown, and red algae?
- Green algae: Chlorophyta
- Brown algae: Phaeophyta
- Red algae: Rhodophyta.
How are plants different from seaweeds?
Unlike seaweeds, plants have true leaves, stems, roots, and vascular tissues. Seaweeds lack vascular systems and have structures like holdfasts instead of roots
What are some notable seaweeds and their uses?
- Ulva (sea lettuce): Edible.
- Irish moss: Used in dairy products (carrageenan).
- Asparagopsis: Helps reduce methane in cattle.
What does sessile mean?
Sessile means an organism is permanently attached to a surface and does not move.
What kind of body symmetry do sponges have?
Sponges have no body symmetry; they are asymmetrical.
Why are sponges considered structurally simple?
Sponges are considered structurally simple because they lack true tissues and organs and are made up of specialized cells.
What are spicules?
Spicules are small, spike-like structures that provide structural support to sponges.
What two materials can spicules be made of?
Spicules can be made of silica (siliceous) or calcium carbonate (calcareous).
What is spongin?
Spongin is a protein that forms tough, elastic fibers, providing support to some sponges alongside or instead of spicules.
How do sponges feed?
Sponges feed by filtering water through their pores, trapping food particles with their collar cells.
What is the difference between suspension feeding and deposit feeding?
Suspension feeders capture food particles from the water, while deposit feeders consume particles that settle on the ocean floor
Q: What is radial symmetry?
Radial symmetry is a body arrangement where parts are organized around a central axis. Organisms with radial symmetry can be divided into similar halves by any plane passing through the center. This type of symmetry is commonly found in organisms like cnidarians and echinoderms