Respiratory Systems Across Animal Phyla

What is the primary method of respiration in Phylum Protozoa?

Diffusion of oxygen and carbon dioxide across their cell membrane.

What are anaerobic protozoa?

Protozoan parasites that can survive in environments with oxygen deprivation and use fermentation.

Name a class of protozoa that relies on diffusion for respiration.

Rhizopoda/Sarcodina (e.g., Amoeba) uses diffusion through the plasma membrane.

Which protozoan class includes organisms that can use fermentation?

Mastigophora/Flagellata (e.g., Trypanosoma) can use fermentation.

What type of respiration do Sporozoa primarily exhibit?

Mostly anaerobic respiration.

What is the function of choanocytes in Phylum Porifera?

Choanocytes draw water into the sponge, capture food, and facilitate respiration and waste removal.

How do Calcarea sponges respire?

Through diffusion via body walls, with water flow generated by choanocytes.

What is the respiratory method of Hexactinellida sponges?

Respiration via diffusion through syncytial tissue.

How do Demospongiae sponges facilitate respiration?

Through diffusion assisted by extensive canal systems and choanocyte activity.

What is the primary method of gas exchange in Phylum Cnidaria?

Diffusion directly between their cells and the surrounding water.

What is the gastrovascular cavity in Cnidarians?

A central cavity that functions in both digestion and circulation, facilitating gas diffusion.

How do Box Jelly and Moon Jelly respire?

Box Jelly: diffusion across body surface; Moon Jelly: diffusion through epidermis and gastrodermis.

What is the respiration method for Anemones?

Diffusion across body surface, with tentacles and body wall in contact with water.

How do Physalia respire?

Via diffusion of the epithelial layer.

What is the respiratory method for flatworms in Phylum Platyhelminthes?

Gas exchange occurs by simple diffusion through their moist body surface.

What is the significance of the flat shape of Platyhelminthes?

It increases surface area relative to volume, making diffusion more efficient.

Name a class of Platyhelminthes that are free-living flatworms.

Turbellaria (e.g., Planaria) respire by diffusion through their body surface.

How do Trematoda flatworms respire?

By diffusion inside the host body.

What is the respiration method for Cestoda flatworms?

By diffusion within the intestines of the host.

What is the primary method of gas exchange in Phylum Nematoda?

Diffusion through the cuticle, a flexible outer covering.

What is the body structure of nematodes?

Elongated, cylindrical, unsegmented body.

How does gas exchange occur in nematodes?

Oxygen diffuses in while carbon dioxide diffuses out through the cuticle.

What is the function of the pseudocoelom in nematodes?

It helps circulate gases and nutrients internally.

In which environments are most nematodes found?

Moist soil, freshwater, marine habitats, or as parasites inside host organisms.

How does Ascaris respire?

Through diffusion via its cuticle in the intestinal environment.

How does Trichinella respire?

Through diffusion via its cuticle in host tissues.

What is the respiration method of Caenorhabditis elegans?

Diffusion through its moist cuticle in soil.

How does Dorylaimus respire?

Through diffusion via its body surface in freshwater.

What is the respiration method of Monhystera?

Diffusion through its cuticle in aquatic habitats.

What respiratory strategies do mollusks exhibit?

Diverse strategies linked to aquatic or terrestrial habitats.

What was significant about the respiratory and circulatory systems in mollusks?

They were among the first animal groups to develop dedicated systems.

What is the mantle cavity in mollusks?

A crucial space housing respiratory structures.

How does gas exchange occur in aquatic mollusks?

Via gills (ctenidia).

What is the function of gills (ctenidia) in mollusks?

They increase surface area for efficient gas exchange between water and blood.

What role does the mantle cavity play in mollusks?

It encloses and protects the gills or lungs and facilitates water or air flow.

What is the lung (pulmonary cavity) in terrestrial mollusks?

A modified portion of the mantle cavity lined with blood vessels for gas exchange.

How do clams breathe?

Using gills (ctenidia) in the mantle cavity with cilia circulating water.

How do oysters respire?

Using gills (ctenidia) in the mantle cavity, with cilia moving water for gas exchange.

What is the respiration method of mussels?

Respiration occurs through gills (ctenidia) in the mantle cavity, with cilia creating water flow.

How do terrestrial snails breathe?

Using a lung (pulmonary cavity) within their mantle cavity.

What is the respiration method of nautilus?

Using gills in the mantle cavity, drawing in and expelling water for respiration.

How do annelids primarily exchange gases?

Through gas exchange across their body surface.

What is the significance of moisture for annelids?

It is linked to their respiratory efficiency.

What distinguishes annelids from mollusks and arthropods regarding respiration?

Many annelids lack rigid respiratory organs.

How do earthworms respire?

Through diffusion across their moist skin.

What are gills in annelids?

Filamentous or branched structures that increase surface area for gas exchange in aquatic species.

What are parapodia in some polychaetes?

Paired, fleshy appendages that aid in gas exchange and locomotion.

What is the primary method of respiration for earthworms?

Diffusion across their moist skin, which is highly vascularized.

How do leeches primarily respire?

Primarily through diffusion across the skin; some aquatic leeches may have gill-like structures.

What respiratory structures do polychaete worms possess?

Gills located on parapodia, which are fleshy, paddle-like appendages on each segment.

How do Tubifex worms increase oxygen uptake?

They wave their posterior end in the water to enhance diffusion across their thin body wall.

Where are the gills located in lugworms?

In the middle segments of their body.

What is a key characteristic of arthropod respiratory systems?

They are highly diverse and efficient, adapted to various habitats.

What respiratory system do terrestrial arthropods like insects and myriapods use?

A tracheal system, which is a network of branching tubes delivering oxygen directly to cells.

What are book lungs and which organisms possess them?

Stacked, plate-like structures within an internal chamber used for aerial respiration, found in arachnids.

How do aquatic arthropods extract oxygen?

They rely on gills, which are feathery or filamentous structures.

What are spiracles in the context of arthropod respiration?

External openings of the tracheal system that regulate air flow.

Describe the tracheal system in grasshoppers.

A network of internal tubes (tracheae) that branch throughout the body, with air entering through spiracles.

How do spiders respire?

Using book lungs and some also have tracheae; air enters through spiracles and circulates between lamellae.

Where are the gills located in crabs?

In a branchial chamber covered by the carapace, with water flowing over the gills.

What respiratory system do butterflies have?

A tracheal system similar to grasshoppers, with spiracles for air entry.

How do centipedes respire?

Through a tracheal system with spiracles located along the sides of their body.

What is a defining feature of echinoderms?

They are marine invertebrates with radial symmetry as adults and lack complex organs.

How do echinoderms primarily respire?

Through diffusion, a passive movement of gases across moist surfaces.

What are the main structures used for gas exchange in echinoderms?

Papulae (dermal branchiae) and tube feet, which are part of the water vascular system.

What is the process of respiration in echinoderms?

Water enters through the madreporite, which is a sieve-like opening.

Name three classes of echinoderms.

Asteroidea (sea stars), Echinoidea (sea urchins), Holothuroidea (sea cucumbers).

How do gases move in echinoderms like sea stars?

Gases move passively via diffusion into the coelom through tube feet and papulae.

What is the role of tube feet in echinoderms?

Tube feet help with both movement and gas exchange.

What is the function of papulae in sea stars?

Papulae (skin gills) increase surface area for respiration.

What are the key characteristics of all chordates?

All chordates have a notochord, dorsal nerve cord, pharyngeal slits, and a post-anal tail.

What are the major subgroups of Phylum Chordata?

Urochordata (tunicates), Cephalochordata (lancelets), and Vertebrata.

How do lancelets and sea squirts breathe?

Lancelets and sea squirts use gill slits for gas exchange.

What is the process of gas exchange in aquatic chordates?

Water enters the mouth, passes over gill filaments, and oxygen diffuses into capillaries through counter-current exchange.

What is the role of the operculum in bony fish?

The operculum protects and pumps water across the gills.

Describe the pathway of air in terrestrial chordates during respiration.

Air flows from the nose to the pharynx, trachea, bronchi, bronchioles, and finally to the alveoli.

What happens in the alveoli during gas exchange?

Oxygen diffuses into capillaries and binds to hemoglobin, while carbon dioxide diffuses from blood into alveoli to be exhaled.

What is the function of the diaphragm in respiration?

The diaphragm is a dome-shaped muscle that helps expand the lungs during inhalation.

How do birds achieve efficient gas exchange?

Birds have unidirectional airflow through rigid lungs supported by air sacs, allowing gas exchange even during exhalation.

What is the significance of hemoglobin in the respiratory systems of chordates?

Hemoglobin carries oxygen throughout the body after it diffuses into capillaries.

What are the respiratory adaptations of terrestrial chordates?

Terrestrial chordates have lungs for gas exchange with air.

How do aquatic forms of mollusks breathe?

Aquatic mollusks use gills (ctenidia) for gas exchange.

What type of respiration do annelids use?

Annelids use moist skin (cutaneous respiration) or parapodia/gills for gas exchange.

What respiratory structures do arthropods use?

Aquatic arthropods use gills, while terrestrial arthropods use tracheal tubes or book lungs.

How do nematodes perform gas exchange?

Nematodes rely on diffusion through their cuticle and body wall.

What is the respiratory system description for phylum Porifera?

Gas exchange occurs by diffusion as water flows through pores into internal canals.

What is the respiratory system description for phylum Cnidaria?

Gas exchange occurs by diffusion across the body wall, with cells in direct contact with water.

What is the respiratory system description for phylum Platyhelminthes?

Flat bodies allow for diffusion through the skin.

What is the respiratory system description for phylum Echinodermata?

Gas diffusion occurs through dermal branchiae (papulae) and tube feet; no lungs are present.

What is the respiratory system description for phylum Chordata?

Aquatic chordates use gills, while terrestrial chordates use lungs, with blood containing hemoglobin to carry oxygen.