Marine Biology Exam 2

Spring 2025 - PCC BI-142 - Mandy Cook

macroalgae

Large seaweeds commonly found in marine ecosystems, providing habitat and food for various marine organisms.

taxonomy

The classification of organisms into groups based on shared characteristics, particularly within marine biology to categorize different species of macroalgae and other organisms.

domain

A highest level of classification in biological taxonomy, comprising the largest groups of life forms, including Archaea, Bacteria, and Eukarya.

kingdom

A rank in biological classification that falls below domain and includes groups of related phyla, such as Plantae and Animalia

phylum

A level of classification in taxonomy that groups together related classes of organisms, such as Chordata and Mollusca

blade

The flat, leaf-equivalent tool for photosynthesis found in macroalgae

stipe

The stalk-like structure of a seaweed or kelp that supports the blade, often resembling the stem of a plant.

holdfast

Root-equivalent for a marine macroalgae that helps them attach to substrate

photosynthetic pigment

A molecule that captures light for photosynthesis, like chlorophyll, carotenes, xanthophylls, etc. Give the algae its color aswell

Gross primary production

The total amount of organic matter produced by photosynthetic organisms in a given area and time, before any is used for respiration

Net primary production

The amount of energy left over for growth of organisms after cellular respiration has occurred

Autotroph

An organism that produces its own food

Heterotroph

An organism that obtains its energy by consuming other organisms or organic matter

Respiration

The process by which organisms convert oxygen and glucose into energy, carbon dioxide, and water

Photosynthesis

The process by which green plants, algae, and some bacteria convert light energy into chemical energy, producing oxygen and glucose from carbon dioxide and water.

Compound Microscope

A type of optical microscope that uses multiple lenses to magnify small objects, such as cells and microorganisms.

Pycnocline

A distinct layer in a body of water where the density changes rapidly with depth, affecting the distribution of marine life and physical properties.

Cyanobacteria

Photosynthetic bacteria that produce oxygen and are important in aquatic ecosystems. Found in the intertidal zones, and fossilize well. Include Anabeena, which we saw very clearly on our microscopes

Coccolithophores

microscopic algae with calcium carbonate plates, crucial for oceanic carbon cycling. We used to make chalk out of them!! VERY important CO2 sink

Diatoms

A major group of algae known for their silica cell walls, important for phytoplankton production and as a food source in aquatic ecosystems. The ones we had that looked like confetti

Silicoflagellates

Microscopic bacteria that can MOVE

Protista

a diverse group of eukaryotic microorganisms, including algae and protozoa

Ochrophyta

Brown algae

Rhodophyta

Red algae

Chlorophyta

Green algae

nitrification

the biological process that converts ammonia into nitrites and then into nitrates in the nitrogen cycle.

anthophyta

Marine flowering plants. Manatees eat them. Mangrove trees!

Emergent

Plants that breach the water’s surface

Radial symmetry

Body parts fan out equally so that no matter how you cut it, you have two equal halves

Pentamerous Radial Symmetry

Body is arranged in five equal parts, so that you can cut it five different ways and have equal halves. Like Echinoderms

Bilateral Symmetry

Left and right sides of the body mirror each other. Most common in chordates

Endoskeleton

A structural support system located internally within an organism, often made of cartilage or bone, found in vertebrates and some invertebrates. Our chordates

Exoskeleton

Skeleton and body support is on the OUTSIDE, like with Arthropods and Molluscs

Hydrostatic skeleton

Find in Cnidarians and some other marine invertebrates. Found in some eucoelomates like the annelids. Moves the animal when they don’t have a hard skeletal support

Anterior

Head of the animal

Posterior

Rear of the animal

Ventral

Bottom of the animal

Dorsal

Top of the animal

Cnidocyte

Where the stingers of the Cnidarians are stored

Nematocyst

The stingers found in Cnidarians. A synapomorphy for the phylum

Medusa

The free-swimming form of a Cnidarian

Polyp

The sessile form of a Cnidarian

Gastrovascular Cavity

The bag-like digestion spot inside of a Cnidarian. Part of an INCOMPLETE digestive track. Pre worm….

Oral

Side of the animal with the mouth

Aboral

Side of the animal that does not have the mouth

coelem

fluid-filled body cavity

cephalization

The organization of specialized sense organs near the brain found in Cephalopods, like squid and octopuses

Larval

A newly hatched form of a creature before it metamorphosizes or otherwise changes

Spicule

What serves as the “skeleton” for a porifera- spiny!

Dioecious

Sexually dimorphic

Hermaphroditic

Having both female and male reproductive organs

Hypoosmatic

LOWER salt content than surrounding water

Hyperosmotic

HIGHER salt content than surrounding water. Hyper → hypo flow

Isosmotic

EQUIVALENT salt content

Osmoconformer

Do NOT actively move water/salt into/out of the body. Body has the same salt content as surrounding water. Like a sea cucumber

Osmoregulator

Water passively leaves the body and must be actively replaced. SALT must be actively removed/added to the body

Gills

How fish convert oxygen in the water for cellular respiration

Gill arch

Supports gill filaments

Notochord

Synapomorphy to be a chordate. An embryonic skeleton that’s next to the dorsal hollow nerve chord

Limiting Factor

Environmental condition that limits population growth

Synapomorphy

Something you MUST have to belong to a phylum

Apron

How do you determine the sex of a blue crab?

Bivalvia

Class of Mollusc. Benthic and have two-part shells

Cephalopoda

Class of Mollusc. No shell, have tentacles with suckers.

Gastropoda

Includes shells, snails, and limpets. Shell is often one piece or absent

Polyplacophora

Eight piece shell class belonging to Molluscs

Byssal threads

How mussels attach themselves to rocks

Arthropoda

Phylum that contains crabs and other critters that are segmented with jointed appendages