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
What are the oral and aboral surfaces?
The oral surface is the side of the organism where the mouth is located, typically facing upward in organisms like sea anemones. The aboral surface is the opposite side, away from the mouth, often used for attachment to surfaces or facing the substrate
What type of body symmetry do Cnidarians have?
Cnidarians have radial symmetry, meaning their body parts are arranged around a central point, which allows them to interact with the environment from all sides.
How do the medusa and polyp body forms compare?
The medusa is a free-swimming, bell-shaped form with the mouth and tentacles facing downward, typical of jellyfish. The polyp is a sessile, tube-like form with the mouth and tentacles facing upward, typical of anemones and corals
What are nematocysts and what are they used for?
Nematocysts are specialized stinging cells found in Cnidarians. They are used to capture prey and for defense by injecting toxins through barbed or thread-like structures
What is a statocyst?
A statocyst is a small organ found in Cnidarians that helps them sense their orientation in the water and maintain balance
Do Cnidarians have a true brain?
No, Cnidarians do not have a true brain. Instead, they have a simple nerve net that allows for basic movements and responses
Compare the classes Scyphozoa, Anthozoa, and Hydrozoa in Cnidaria.
Scyphozoa: This class includes the larger jellyfish, where the medusa is the dominant stage.
Anthozoa: This class includes sea anemones and corals, where only the polyp stage exists. They lack a medusa stage.
Hydrozoa: These organisms often have both polyp and medusa stages and can form colonies, like the Portuguese man-of-war
What type of body symmetry do comb jellies have?
Comb jellies exhibit radial symmetry, similar to cnidarians, meaning their body parts are arranged around a central axis .
How many comb rows of cilia do comb jellies have?
Comb jellies have eight rows of ciliary combs, which are fused cilia that beat in waves .
What do comb jellies use their cilia for?
Comb jellies use their cilia for locomotion. The beating of the ciliary combs propels them through the water .
What is bilateral symmetry?
Bilateral symmetry is the arrangement of body parts in such a way that there is only one way to divide the body into two identical halves
What are the dorsal, ventral, anterior, and posterior surfaces?
- Dorsal: The upper side or back of an organism.
- Ventral: The lower side or belly.
- Anterior: The front end, usually containing the head.
- Posterior: The rear or tail end .
What type of body symmetry do flatworms (Phylum Platyhelminthes) have?
Flatworms have bilateral symmetry .
Do flatworms have true organs and tissues?
Yes, flatworms are the simplest animals with tissues organized into true organs and systems .
Are flatworms parasitic, free-living, or both?
Flatworms can be both parasitic (such as flukes and tapeworms) and free-living .
What type of body symmetry do roundworms (Phylum Nematoda) have?
Roundworms have bilateral symmetry .
What is the general body shape of roundworms?
Roundworms have a slender, cylindrical body, typically pointed at both ends .
Where in the ocean can roundworms be found?
Roundworms are commonly found in marine sediments, particularly in areas rich in organic matter .
What is a hydrostatic skeleton?
A hydrostatic skeleton is a structure where muscles push against a fluid-filled body cavity, providing support and enabling movement, as seen in nematodes .
What is segmentation in annelids (Phylum Annelida)?
Segmentation is the division of the body into repeated sections, each containing similar organs and structures. This gives annelids, like earthworms and polychaetes, flexibility and mobility .
What is the function of parapodia in polychaetes?
Parapodia are flattened extensions on each segment of polychaetes, often equipped with bristles, used for locomotion and sometimes for respiration .
What structures can be found on the head of a crawling polychaete worm?
The head of a crawling polychaete worm may have sensory structures such as eyes, tentacles, and palps
What do tube-dwelling polychaetes make their tubes out of?
Tube-dwelling polychaetes create their tubes from various materials such as sand, mud, or mucus .
How do tube-dwelling polychaetes use their tentacles to catch food?
Tube-dwelling polychaetes extend their tentacles outside their tubes to capture food particles from the water, which they then transport to their mouths .
What type of body symmetry do mollusks (Phylum Mollusca) have?
Mollusks exhibit bilateral symmetry, with body parts divided into symmetrical halves.
What is the function of the mantle in mollusks?
The mantle is a layer of tissue that secretes the mollusk’s shell and also houses the gills and excretory organs.
What is the function of the foot in mollusks?
The foot in mollusks is a muscular structure used for locomotion and anchoring the animal to surfaces.
What is a radula and what is it used for?
A radula is a ribbon of tiny teeth used by mollusks to scrape food, such as algae, from surfaces
How many shells does a typical gastropod have?
A typical gastropod has a single, often coiled, shell
How do nudibranchs defend themselves?
Nudibranchs often produce toxic chemicals or retain stinging cells (nematocysts) from their prey for defense
How many shells do bivalves have?
Bivalves have two shells that are hinged together
How do bivalves feed, and what is the main function of the siphon?
Bivalves filter-feed by drawing water through their gills to capture food particles. The siphon helps in bringing water in and out of the body for feeding and respiration
How do mussels attach to rocks?
Mussels attach to rocks using byssal threads, which are strong, protein-based fibers
What is unique about the foot of cephalopods?
In cephalopods, the foot is modified into arms and tentacles used for capturing prey and locomotion
What do cephalopods use their siphon for?
Cephalopods use their siphon for jet propulsion, expelling water to move quickly through the water
How many arms does an octopus have?
An octopus has eight arms
What do octopuses eat, and how do they bite their prey?
Octopuses eat crustaceans, mollusks, and fish. They bite their prey with a beak and use their radula to further break down the food
Compare the anatomy of squids and octopuses.
Squids have eight arms and two longer tentacles, while octopuses have only eight arms. Squids also have an internal shell called a pen, which octopuses lack
What is a squid pen?
A squid pen is a flexible, internal shell that provides support and structure
How many shells do chitons have?
Chitons have eight overlapping shell plates covering their dorsal surface
Where do chitons live, and what do they feed on?
Chitons live on rocky shores and hard bottoms, feeding on algae scraped from the surface using their radula
Compare the general biology of gastropods, bivalves, cephalopods, and polyplacophora (chitons).
- Gastropods: Most have a coiled shell and use a radula for feeding.
- Bivalves: Have two shells and filter-feed through their gills.
- Cephalopods: Lack external shells (except nautiluses) and are predators using arms and tentacles.
- Chitons: Have eight shell plates and feed on algae with a radula
What type of body symmetry do arthropods have?
Arthropods exhibit bilateral symmetry
Are arthropods segmented?
Yes, arthropods are segmented, with body parts arranged in distinct segments
What material is an arthropod’s exoskeleton made of?
An arthropod’s exoskeleton is made of chitin, a tough carbohydrate
Why do arthropods molt?
Arthropods molt to shed their old exoskeleton and grow a new, larger one as they grow
What body structure do crustaceans use to obtain oxygen?
Crustaceans use gills to obtain oxygen from the water
Which specific crustaceans are abundant and important in plankton?
Copepods and krill are abundant crustaceans that play a crucial role in plankton
How do barnacles feed?
Barnacles feed by using feathery appendages called cirri to filter plankton from the water
Describe the body structure of amphipods.
Amphipods are small, laterally compressed crustaceans with a distinct head, thorax, and abdomen
Describe the body structure of isopods.
Isopods are dorsoventrally flattened, with similar thoracic and abdominal segments
Describe the body structure of decapods.
Decapods have a large carapace, five pairs of walking legs, and a well-developed abdomen
