Bio Final Case Study Flashcards
Tentacles
Used for capturing prey (such as plankton) and directing it toward the mouth. They often contain stinging cells (nematocysts) for defense and feeding.
Mouth
The opening through which the polyp ingests food and expels waste.
Gastrovascular Cavity.
A central cavity that serves as the site for digestion and circulation of nutrients throughout the polyp.
Endoderm
The inner cellular layer lining the gastrovascular cavity. It contains specialized cells for digestion and nutrient absorption.
Zooxanthellae
Symbiotic algae residing within the endoderm. They perform photosynthesis, providing energy to the polyp in exchange for nutrients and a protected environment.
Coenosarc
The tissue that connects individual polyps in a coral colony, enabling the sharing of nutrients and communication.
Calyx
The cup-like skeletal structure that houses the polyp, providing protection and support.
Theca
The vertical walls of the calyx, which enclose and protect the polyp.
Basal Plate
The base of the skeletal structure where the polyp is anchored, allowing it to attach securely to the substrate
How do tentacles assist in feeding the coral?
They move and retract to guide captured food toward the mouth.
What do gland cells in the gastrovascular cavity release to break down prey?
Enzymes
Cnidocytes
Specialized cells located on the coral’s tentacles. They are unique to cnidarians (a group that includes corals, jellyfish, and sea anemones).
Nematocysts
Organelles within cnidocytes that act like tiny harpoons. When triggered by contact with prey, nematocysts eject, delivering a toxin that stuns or kills the prey
How does the cnidocytes ands nematocysts help coral feed?
The nematocysts allow the coral to immobilize plankton or other small organisms, making them easier to ingest.
How do stony corals build skeletons?
secreting calcium carbonate (CaCO3) from polyps, a process supported by their symbiotic relationship with zooxanthellae
what factors influence skeleton growth?
want low nutrients so no algal blooms
no acidic (low pH bc reduces CaCO3)
need sunlight for photosynthesis by zooxanthellae
warm tropical water
nutrients, sunlight, pH
Coral Hobiont
Corals:
Zooxanthellae
Cyanobacteria:
Bacteria:
Fungi:
Viruses:
Coral & Holobiont
The host organism that forms the reef structure/protection
- gives co2 to zooxanthellae
Zooxanthellae & Coral Holobiont
Photosynthetic algae providing energy through photosynthesis
-sugar & O2 to coral
Cyanobacteria & Coral Holobiont
Contribute to nitrogen fixation and organic carbon synthesis
- gives Ammonia to coral/zooxanthellae
-
bacteria & Coral Holobiont
Perform diverse roles including nitrogen cycling and breakdown of organic matter
-in coral mucus
Fungi & Coral Holobiont
Help in nutrient cycling and symbiotic interactions
-in coral skeleton
Viruses & Coral Holobiont
Can affect coral health and community structure
-in coral tissue
Coral bleaching & Zooxanthellae
Coral bleaching occurs when corals expel their zooxanthellae, losing their primary source of energy and their pigmentation. The absence of zooxanthellae turns corals white or pale, leaving them highly vulnerable
Cyanobacteria & Importance
Cyanobacteria enhance coral nutrient availability and overall reef productivity by contributing to nitrogen fixation and organic carbon synthesis.
Risks of Coral reefs
coral bleaching caused by ocean warming & acidification
Explain what happens during coral bleaching, and the factors that are associated with it.
Coral bleaching involves the expulsion of zooxanthellae due to stress, leaving the coral white and vulnerable.
Increased absorption of atmospheric CO₂ by seawater, lowering pH levels makes bicarbonate (HCO3 + H+ high acidity)
acidification corrodes skeletons
warmer waters -> heat stress on coral eject zooxanthellae
How do changes in the carbon cycle cause ocean acidification?
CO₂ emissions lead to more CO₂ dissolving in seawater, forming carbonic acid. This lowers ocean pH and reduces carbonate ions needed for coral skeleton formation.
How do changes in the carbon cycle cause ocean acidification & affect coral
Impact on Corals: Weakens coral skeletons, slows growth, and makes them more vulnerable to erosion and damage.
How do changes in the carbon cycle cause ocean warming?
Excess CO₂ traps heat in the atmosphere, raising global temperatures, including sea surface temperatures.
How do changes in the carbon cycle cause ocean warming & affect coral
Elevated temperatures cause coral bleaching by disrupting the coral-zooxanthellae symbiosis, often leading to coral stress or death.
How do stressors like heat or acidification affect energy balance in corals?
Stressors like heat or acidification can disrupt zooxanthellae photosynthesis, reducing energy production in corals and their ability to grow and survive.
