FNR 201 Exam 2

Approximately what percentage of fungi occur in marine environments?

Approximately what percentage of fungi occur in marine environments?

less than 1%

Marine lichen is a symbiosis between which two organisms?

alga and fungus

What are the three main body parts of a macroalgae?

thallus, holdfast, stipe

Name the haploid life cycle stage (i.e. sexual stage) of macroalgae?

spores
(asexual reproduction)

Define compensation depth and how it relates to the distribution of algae?

sunlight sufficient for metabolism, but not for growth
distribution determined mainly by light and temperature
typically inner continental shelf

In addition to chlorophyll a, which type of chlorophyll does red algae have?

chlorophyll d

How do the root systems of red and black mangroves differ?

RED:
stilt roots (aerial roots)
prop roots: high on trunk
drop roots: underside of branches
lenticles: scar-like openings on root surface / connect aerenchyma to atmosphere

BLACK:
roots originate below ground
cable roots: spread away from trunk
anchor roots: penetrate below cable roots
pneumatophores: aerial roots that grow upward from cable

What are the three important parts of seagrass stems?

stems - nodes/internodes/rhizomes
roots - can be branched or not
leaves - sheath and blade

What adaptations do mangroves (3) and salt marsh plants (4) have for living in high salinity environments?

salt marsh plants - leaves have thick cuticle to prevent water loss, well-developed vascular tissues for water transport, specialized glands that secrete salt, and succulent parts have high water content

mangroves: have specialized parts of tree that help to conserve water, supply oxygen to roots, and stabilize the tree in shallow/soft sediment

What food web do marine vascular plants contribute most to?

detrital

Are sponges sessile or sedentary?

sessile = fixed in one place; immobile.

What are the three specialized cells in sponges and their different functions?

archaeocytes - important for repair and regeneration
does most of digestion and stores food
release eggs?
transport food and other materials

choanocytes (collar cells) - have flagella that force water to circulate
traps food
release sperm?

pinacocytes - form the pinacoderm / outer covering

What is the name of the central cavitity in sponges?

spongocoel

What are the three different materials that sponge spicules can be made of?

calcium carbonate - mineralized substance
silica -mineralized substance
spongin - organic substance

What are the two different ways that sponges can asexual reproduce?

budding - buds drop off parent and form new sponge (not common)
fragmentation - new sponge from broken pieces

List the 3 shapes of sponges in order of complexity.

MOST COMPLEX - leuconoid
MIDDLE - syconoid
LEAST COMPLEX- asconoid

What is the larval planktonic stage of a sponge?

amphiblastula

What are the two different life stages of most cnidarians?

polyp - benthic [coral and sea anemones]
medusa - free floating stage [adult jellyfish]

What is the name of spear-shaped cnidae that are most common in cnidarians?

nematocyst

Do Hydrozoans and Scyphozoans have similar reproductive cycles?

yes
both have asexual polyp and sexual medusa stage

How does coral bleaching occur?

loss of zooxanthelle (organisms that have mutualistic symbiosis with coral - coral get nutrients and zooxanthellae get protection)

How do anemones obtain nutrition?

feed mostly on invertebrates and small fish
paralyze fish with nematocysts

What defines a concentration of sensory organs at one end of an animal?

cephalization

List the three main groups of flatworms and indicate if they are parasitic or not

tubellaria - free-living
trematoda - parasitic flukes
cestoda - parasitic tapeworms

What is an organism with radial symmetry that lacks stinging cells and has 8 rows of cilia used for locomotion?

ctenophores

What part of a mollusc is responsible for secreting the shell?

mantle

What class of mollusc has 8 overlapping plates formed from the mantle?
How about a class of mollusc that has an two shell openings, one larger than the other?

8 plates - chitin
2 shells - bivalve

What is the bony flap that covers the shell opening in snails?

operculum

What is the main difference between how gastropods and bivalves obtain nutrition?

bivalves are facilitate filter feeders
gastropods can graze, use chemical trails to locate prey, scavenge/deposit feed, or filter feed depending on the type

In nautiloids, what is the name of the structure that separates the gas-filled chambers in their shell?

septa

List the orders of cephalopods that have an internal shell?

sepiida (cuttlefish)
teuthida (squids)

What is the inky fluid dispelled by coleiods and what is its purpose?

sepia

What are the specialized cells that are used for color change by cephalopds? What are some of the functions of changing shape and color?

chromatophoreds
camouflage and warning to predators

Do all cephalopods have an internal shell-like structure?

no, octopi lack

What is the nutritional strategy of Christmas tree worms - a sedentary polychaete?

predators
catch phytoplankton floating in water with their appendages/feathers

What is the unique system that supports the body structure in annelid worms?

coelom?
internal hollow body cavities that are surrounded by muscle with fluid in between
"small donut surrounded by another, bigger donut"

What is the difference between selective and non-selective deposit feeding polychaetes?

non-selective = eat everything, absorb good stuff, eject waste
selective = sort sediment first, only eat good stuff

List 3 major components of a horseshoe crabs body?

cephalothorax = large with fused head and thorax
abdomen = smaller and has book gills
telson = spike used for steering and defense

What are two types of modified legs in decapods and what are their purpose?

chelipeds/pereiopods = walking legs and used to gather food
maxillipeds ? = function as mouthparts

What are the 4 orders of Malacostraca and what are some of the key characteristics of each order?

Decopoda - most number of species, "10 - feet", 5 pairs of walking legs, [hermit crab]
Isopoda - elongated body, rather flat, back covered with armor-like plates, segmented
Amphipoda - posterior appendages used for jumping, burrowing, and swimming, specialized appendages called gnathopods, eggs fertilized in female's brood chamber
Stomatopoda - most live in crevices and burrows, modified second pair of appendages = enlarged and movable finger, smashers and spearers

What are two different types of modified appendages that stomatopods use to capture prey?

smashers = club-shaped appendages to crush hard prey
spearers = spear-shaped appendages to impale soft prey

How do crustaceans grow in size when they have a hard, rigid exoskeleton?

molting - shed and replace exoskeleton

How do barnacles feed?

feathery appendages extend from shell to filter feed