BIO 2 -- Invertebrates

Which of the following is not a feature of sponges (Parazoa)?
a) Hox genes
b) Cellular organization
c) Choanocytes
d) Saclike bodies with pores (ostia)

Hox genes

True or False:
Sponges have a well-defined body plan with distinct tissue layers.

false (no true tissue layers)

The beating of the ________ on the choanocytes helps to draw water into the body of the sponge.

flagelli

What is the primary function of choanocytes in sponges?
a) They trap food particles and phagocytize them
b) They provide structural support to the sponge
c) They help with the excretion of waste
d) They provide a circulatory system for the sponge

They provide structural support to the sponge

True or False:
Archeocytes in sponges are totipotent cells that can differentiate into any other cell type as needed.

true

The ________ is the nonliving layer located between the choanocytes and the pinacocytes in sponges.

mesohyl

What is the function of the ostia in sponges?
a) They release waste products from the sponge
b) They allow water to enter the sponge
c) They help regulate the sponge's temperature
d) They house the choanocytes

They allow water to enter the sponge

True or False:
Sponges can grow to any size, limited only by their nutritional needs.

true (sponges are amorphous)

________ are amoeboid cells in sponges that can wander through the body and differentiate into other cell types.

Archeocytes

Which of the following is a characteristic unique to Parazoa (sponges)?
a) Presence of Hox genes
b) Presence of a central nervous system
c) Lack of true tissues and organs
d) Presence of a circulatory system

Lack of true tissues and organs

What is the function of the collar of microvilli?

Traps food particles which is phagocytized by the choanocyte

What is the primary function of spicules in sponges?
a) Reproduction
b) Movement
c) Support
d) Water filtration

support

True or False:
Spicules in sponges are composed of spongin and either silica or calcium carbonate.

true

Sponges are ________ filter feeders, meaning they remain stationary and feed by drawing water through their bodies.q

sessile

Which of the following describes the Asconoid body type in sponges?
a) Flagellated canals and tubular body
b) Flagellated spongocoel and small, tube-shaped structure
c) Multiple flagellated chambers
d) Most complex and largest body type

Flagellated spongocoel and small, tube-shaped structure

True or False:
Sponges can reproduce sexually only, through the formation of gemmules.

false — reproduce asexually by fragmentation or budding

________ are balls of totipotent cells formed by sponges in response to harsher environmental conditions.

gemmules

The Syconoid body type in sponges differs from the Asconoid in that it features:
a) A single flagellated spongocoel
b) Flagellated canals and a central atrium
c) A large, flagellated central chamber
d) No flagellated areas

A large, flagellated central chamber

The ________ body type is the most complex and largest form of sponge, with flagellated chambers and is the most abundant and successful body type in sponges.

leuconoid

In Leuconoid sponges, water enters the ________, flows into the flagellated chambers, then travels through the excurrent canal, and exits via the osculum.

a) Incurrent canal
b) Spongocoel
c) Central atrium
d) Flagellated spongocoel

Incurrent canal

What is the function of archaeocytes?

amoeboid cells that wander through the body of the sponge; responsible for digestion, transport of nutrients and differentiation into other cell types

What is the scientific name for sponges?

Porifera

How does volume relate to area of the flagellated areas of sponges?

• The more flagellated chamber the sponge has (the bigger the surface area), the velocity will decrease

• The slower the flow of the water, the more time the sponge has to feed, the bigger it gets to grow

• Relates to the human circulatory system

Which of the following best describes the symmetry and tissue organization in cnidarians?
A. Bilateral symmetry; triploblastic
B. Radial symmetry; diploblastic
C. Asymmetry; diploblastic
D. Bilateral symmetry; diploblastic

Radial symmetry; diploblastic (Cnidarians exhibit radial symmetry and are diploblastic (two tissue layers).)

What is the primary function of cnidocytes in cnidarians?
A. Digestion of food
B. Water regulation
C. Defense and prey capture
D. Reproduction

Defense and prey capture

Which statement about the medusa and polyp forms is TRUE?
A. They are not homologous structures
B. The polyp is adapted for swimming
C. The medusa is adapted for floating in open water
D. Both forms are always present in every cnidarian species

The medusa is adapted for floating in open water

What causes the nematocyst to discharge from a cnidocyte?
A. Changes in temperature
B. Light exposure
C. Mechanical or chemical stimulation triggering osmotic pressure release
D. Electrical impulses from the nerve net

Mechanical or chemical stimulation triggering osmotic pressure release

T/F: Cnidarians have a complete digestive tract with separate mouth and anus.

false (They have a sac-like gut with only one opening—food enters and waste exits through the same hole.)

T/F: The mesoglea in cnidarians is a non-living, jelly-like substance found between the epidermis and gastrodermis.

true

T/F: Cnidarians possess a centralized nervous system to coordinate movement.

false (They have a nerve net, not a brain or centralized system.)

T/F: The discharge of a nematocyst is among the fastest known physiological processes.

true

Cnidarians have two body forms: the ________ form is free-floating, while the ________ form is sessile.

medusa, polyp

Specialized stinging cells called ________ are located on the tentacles of cnidarians.

cnidocytes

The cnidocyte contains a fluid-filled capsule called a ________, which houses the coiled thread known as a ________.

cnidae; nematocyst

The central body cavity used for digestion in cnidarians is called the ________ ________.

gastrovascular cavity

Cnidarians move with slow, passive motions due to the absence of a muscular system and the need to retain food in the ________.

gastrovascular cavity

Cnidarians have a ________ level of organization and are classified as ________ because they possess two germ layers.

tissue; diploblastic

Which body form dominates the life cycle of Scyphozoa?
A. Polyp
B. Medusa
C. Planula
D. Both polyp and medusa equally

Medusa (Scyphozoans (true jellyfish) are dominated by the medusa form, which is the free-floating adult stage.)

what is characterized by a Scyphozoa which falls under the cnidarian?

jellyfish

What is the function of the statocyst in Scyphozoa?
A. Food digestion
B. Photoreception
C. Balance and gravity sensing
D. Reproduction

Balance and gravity sensing

Which of the following statements is TRUE regarding the reproductive biology of Scyphozoans?
A. They are hermaphroditic
B. They reproduce by binary fission
C. They have separate sexes
D. They reproduce only asexually

They have separate sexes

Which structures are found in the rhopalium of jellyfish?
A. Manubrium and oral lobes
B. Tentacles and nematocysts
C. Statocysts and ocelli
D. Mesoglea and cnidocytes

Statocysts and ocelli (The rhopalium contains statocysts (balance) and ocelli (light detection).)

T/F: The polyp stage is entirely absent in the Scyphozoan life cycle.

false (Scyphozoans have a polyp stage, though it is less dominant than the medusa.)

T/F: The medusa of Scyphozoans contains a thick layer of mesoglea.

true (The mesoglea is the jelly-like substance that helps the medusa maintain buoyancy.)

T/F: Ocelli in jellyfish function as light-detecting structures.

true

The sensory organ in Scyphozoans that contains both statocysts and ocelli is called the ________.

rhopalium

What is the correct sequence of developmental stages in the jellyfish life cycle?
A. Egg → Ephyra → Scyphistoma → Planula → Adult
B. Egg → Planula → Scyphistoma → Ephyra → Adult
C. Egg → Scyphistoma → Planula → Ephyra → Adult
D. Planula → Egg → Scyphistoma → Ephyra → Adult

Egg → Planula → Scyphistoma → Ephyra → Adult

What is the purpose of jellyfish forming a group, or "smack"?
A. To increase speed while swimming
B. To deter predators
C. To improve chances of fertilization
D. To share food resources

To improve chances of fertilization

Strobilation refers to which of the following?
A. Sexual reproduction through fertilization
B. Attachment of the planula to a substrate
C. Asexual reproduction in the scyphistoma
D. Growth of ephyra into adults

Asexual reproduction in the scyphistoma (lots of clones)

What is the ecological consequence of jellyfish thriving due to climate change?
A. Increased oxygen production
B. Reduced food availability for coral reefs
C. Decreased water temperature
D. Predation on larval fish, affecting fish populations

Predation on larval fish, affecting fish populations

T/F: The scyphistoma can reproduce sexually and produce ephyra.

false (The scyphistoma reproduces asexually through strobilation to release ephyra.)

T/F: Jellyfish release both egg and sperm into the water column for external fertilization.

true

T/F: The ephyra is the sessile stage of the jellyfish life cycle.

false (The ephyra is the free-swimming juvenile stage; the scyphistoma is the sessile polyp stage.)

T/F: A large reproductive output in jellyfish helps offset high levels of predation.

true

The motile larval stage of the jellyfish is called the ________ larva.

planula

After settling on a solid surface, the planula becomes a feeding polyp called a

scyphistoma

Asexual reproduction in jellyfish, where clones bud off from a polyp, is called ________.

strobilation

The free-swimming juvenile form of jellyfish that buds off during asexual reproduction is the ________.

ephyra

how long will the scyphistoma stay on a solid surface for attachment and feeding?

1-2 years

Which of the following correctly distinguishes Cubozoans from Scyphozoans?
A. Cubozoans only exist in the polyp stage
B. Cubozoans are passive swimmers
C. Cubozoans are categorized solely by the medusa stage
D. Cubozoans lack tentacles

Cubozoans are categorized solely by the medusa stage (nlike Scyphozoans, which have both medusa and polyp stages, Cubozoans are medusa-only in classification.)

Which of the following toxins associated with Cubozoan stings affects the heart?
A. Neurotoxic
B. Dermonecrotic
C. Cardiotoxic
D. Cytotoxic

Cardiotoxic

he tentacles of Cubozoans are located:
A. All along the edge of the bell
B. At the center of the bell
C. Randomly dispersed
D. At the corners of the bell

At the corners of the bell

T/F: Cubozoans are considered more dangerous than other jellyfish due to their fast-swimming abilities and potent venom.

true (They are active swimmers and produce powerful toxins, making them more dangerous than most jellyfish.)

T/F: The sea wasp (Chironex fleckeri) is harmless to humans.

false

T/F: Cubozoan toxins can interfere with both cardiac and respiratory functions.

true (cardiotoxins and neurotoxins)

T/F: Cubozoans have a polyp-dominant life cycle.

false (They are medusa-dominant and are classified solely by the medusa stage.)

The sting of a box jelly can cause ________ damage, which results in permanent scarring.

dermonecrotic

The species Chironex fleckeri, also known as the ________, is extremely deadly to humans.

sea wasp

Compared to Scyphozoans, Cubozoans are ________ swimmers.

active

Which of the following best describes the dominant life stage of Hydrozoans?

• a) Medusa

• b) Planula larva

• c) Polyp

• d) Egg

• Polyp

hat is the primary function of the gastrozooids in a Hydrozoan colony?

• a) Reproduction

• b) Protection

• c) Feeding

• d) Buoyancy

• Feeding

Which of the following best describes the colony structure of Hydrozoans?

• a) A group of medusae sharing a common stomach

• b) A group of polyps sharing a common gastrovascular cavity

• c) A single large polyp with multiple mouths

• d) Individual polyps without any connection

• A group of polyps sharing a common gastrovascular cavity

What is the role of gonozoids in a Hydrozoan colony?

• a) Feeding polyps that capture prey

• b) Medusae-producing reproductive polyps

• c) Tentacle-like appendages for defense

• d) Floatation and mobility

• Medusae-producing reproductive polyps

T/F: Hydrozoans have a complex life cycle that involves both asexual budding and sexual reproduction through medusae.

true

T/F: The Portuguese man 'o war is a single organism that consists only of medusae.

false (contains both medusa and polyp)

T/F: In Hydrozoans, the polyps are genetically diverse and not interconnected.

false (The polyps are genetically identical and interconnected, sharing a common gastrovascular cavity)

The ________ is the reproductive polyp in Hydrozoans, which produces medusae.

gonozoid

The Portuguese man 'o war's medusa form creates a giant ________ filled with carbon monoxide that helps it float on the water's surface.

gas filled bag

where are hydrozoans found?

marine environments and freshwater

What is the significance of the common gastrovascular cavity in Hydrozoan colonies?

The common gastrovascular cavity connects the polyps, allowing them to share nutrients and function as a coordinated group. This connection helps in efficient feeding and growth within the colony.

T/F: Hydrozoans undergo both asexual and sexual reproduction

true (asexually budding to give rise to clones and more connected polyps) and undergo sexual reproduction to produce meduse

Which of the following is true regarding the life cycle of Anthozoa?

a) They have both a polyp and medusa stage.

b) They only exist in the medusa form.

c) They are exclusively in the polyp form with no medusa stage.

d) They can alternate between polyp and medusa stages.

They are exclusively in the polyp form with no medusa stage.

Which structure in sea anemones helps pump water in and out of the gastrovascular cavity? a) Pedal disk b) Siphonoglyph c) Septa d) Acontia

Siphonoglyph

What is the function of the calcareous cups secreted by polyps in coral reefs? a) To provide structural support to the anemone. b) To store energy for the zooxanthellae. c) To build the framework of coral reefs. d) To capture prey.

To build the framework of coral reefs

Which of the following is a characteristic of the sea anemone's attachment to surfaces? a) It attaches by a calcified skeleton. b) It attaches via a pedal disk. c) It attaches via tentacles. d) It attaches by using nematocysts.

It attaches via a pedal disk.

True or False: Anthozoans possess both a medusa and polyp stage during their life cycle.

false

True or False: Coral reefs are formed by hermatypic corals that have a symbiotic relationship with zooxanthellae.

true

True or False: Pedal laceration in sea anemones is a form of asexual reproduction where parts of the pedal disk regenerate into new individuals.

true

The gastrovascular cavity of Anthozoans is divided into sections by internal walls called _________.

septa

The defensive fibers that shoot out from the body wall of Anthozoans are called

acontia

Anthozoans, such as sea anemones and corals, attach to surfaces via the ________, which serves as a means of attachment.

petal disk

What are anthozoans?

• stationary

• flower animals

• sea anemones (solitary individuals), hard corals and sea fans (colonial individuals)

Explain the role of zooxanthellae in the formation of coral reefs.

Zooxanthellae are photosynthetic algae that live in a symbiotic relationship with corals. They provide energy to the corals through photosynthesis, which helps build the calcareous skeletons that form the structure of coral reefs.

What is the primary role of Zooxanthellae in the coral symbiotic relationship?
a) To provide CO2 for the corals
b) To perform photosynthesis and generate oxygen and carbohydrates for the corals
c) To lay down calcium carbonate for the coral's skeleton
d) To protect the coral from predators

To perform photosynthesis and generate oxygen and carbohydrates for the corals

True or False

Corals can obtain all their nutrients from the surrounding water column, without the help of Zooxanthellae.

false (Corals live in nutrient-poor waters and supplement their diet with the products of Zooxanthellae photosynthesis.)

he mutualistic relationship between corals and Zooxanthellae is essential for the coral's survival because the Zooxanthellae provide the corals with ___________ and ___________ produced during photosynthesis.

oxygen and carbohydrates

In which type of environment do corals primarily thrive?
a) Cold, nutrient-rich waters
b) Warm, clear, tropical waters
c) Deep, dark oceanic waters
d) Freshwater lakes

Warm, clear, tropical waters

Coral calcification occurs more quickly in the absence of light.

false (Coral calcification occurs faster in the presence of light, as light supports photosynthesis and increases the calcium carbonate deposition.)

Which of the following is true about coral polyps and their calcium carbonate secretion?
a) Older corals secrete calcium carbonate at a faster rate than younger corals
b) Younger corals secrete calcium carbonate faster than older corals
c) Coral polyps do not secrete calcium carbonate
d) Coral polyps secrete calcium carbonate at the same rate throughout their life

Younger corals secrete calcium carbonate faster than older corals

Coral reefs are found in shallow, __________ waters with a salinity level typical of normal seawater.

warm