Respiratory organs Questions in English

(C) $1$. Silver fish $(Lepisma)$ is an insect, and insects respire through a tracheal system $(Trachea)$. Thus, $I$ is correct.
$2$. Scorpion is an arachnid, and it respires through book lungs. Thus, $II$ is correct.
$3$. Sea squirt $(Urochordata)$ respires through pharyngeal gill slits. Thus, $III$ is correct.
$4$. Dolphin is a mammal, and it respires through lungs, not skin. Thus, $IV$ is incorrect.
Therefore, the correct matchings are $I, II,$ and $III$.

(B) The respiratory organs in animals are adapted to their specific environmental conditions. Because of different habitats (the place where an animal lives) and the complexity of their body structure (level of organisation),the breathing mechanisms vary significantly. Consequently,the respiratory organs also vary across different animal groups to ensure efficient gas exchange.

(A) Insects (e.g.,Cockroach) respire through a network of tubes called the Tracheal system.
Gills are respiratory organs found in aquatic animals like fish and some amphibians.
Cuticle (moist skin) is the respiratory organ in earthworms.
Lungs are the respiratory organs in birds,reptiles,and mammals.

(B) Frogs can respire by their moist skin,buccal cavity,and lungs as they live on land. Their larval form,i.e.,tadpole,which lives in water,respires through gills.
$Hydra$ and $Sycon$ do not have a well-developed respiratory system; they perform the exchange of gases by simple diffusion.
Earthworms respire through their moist cuticle.

(D) Aquatic arthropods (such as crayfish and prawns) and aquatic molluscs (such as $Unio$) respire through specialized vascularized structures called gills (branchiae).
These organs are adapted for the exchange of dissolved oxygen from the water into the blood and the removal of carbon dioxide from the blood into the water.

(D) The respiratory organs vary across different animal groups based on their habitat and level of organization:
$1$. Earthworms respire through their moist cuticle,while insects use a tracheal system.
$2$. Sponges,coelenterates,and flatworms do not have specialized respiratory organs; they exchange gases through simple diffusion across their body surface.
$3$. Fishes and aquatic arthropods typically use gills for respiration.
$4$. Reptiles,birds,and mammals possess well-developed lungs as their primary respiratory organs.
Therefore,the correct group of animals that respire through lungs is reptiles,birds,and mammals.

(C) respiratory surface must possess specific characteristics to facilitate efficient gas exchange. These include being thin,moist,and having a large surface area (extensive). Furthermore,it must be highly vascular,meaning it is well-supplied with blood vessels,to ensure the rapid transport of oxygen and carbon dioxide between the respiratory surface and the blood. Therefore,'least vascular' is not a characteristic of a respiratory surface.

(D) Human skin cannot act as a respiratory organ for several reasons:
$1$. It is dry,which prevents the dissolution and diffusion of gases.
$2$. It is not thin enough to allow for efficient gas exchange.
$3$. It is impermeable to $O_2$ and $CO_2$,meaning these gases cannot pass through the skin layers effectively.
Therefore,all the given options are correct.

(B) Assertion is true: Birds possess air sacs connected to their lungs. These $8$ or $9$ air sacs are situated on either side of the lungs and help in maintaining a continuous flow of air.
Reason is true: Air sacs significantly increase the efficiency of respiration in birds. They ensure that air passes over the gas exchange surfaces in a unidirectional manner,preventing the mixing of oxygenated and deoxygenated air.
Conclusion: While both statements are scientifically accurate,the presence of air sacs (anatomical feature) is not the direct cause of them supplementing respiration (physiological function); rather,they are structural adaptations that facilitate the process. Therefore,the Reason is not the correct explanation of the Assertion.

(D) Amphibians exhibit a diverse range of respiratory mechanisms depending on their life stage and environment.
$1$. Cutaneous respiration: Many amphibians,such as frogs,can respire through their moist skin.
$2$. Pulmonary respiration: Adult amphibians possess lungs for breathing air.
$3$. Branchial respiration: Larval stages (tadpoles) of amphibians respire through gills.
Therefore,amphibians can respire through skin,lungs,and gills.

(D) In plants,different parts have specialized structures for gas exchange:
$1$. Leaves and young stems contain stomata $(II)$ for the exchange of gases.
$2$. Woody stems have specialized openings called lenticels $(I)$ that allow for gas exchange.
$3$. Roots absorb oxygen from the soil through root hairs $(III)$.
Therefore,the correct matching is $P-II, Q-I, R-III$.

(A) The correct matching of invertebrates with their respiratory organs is as follows:
$P$. Sponges,Coelenterates,and Flatworms respire through simple diffusion across their entire body surface $(II)$.
$Q$. Earthworms use their moist skin (moist cuticle) for respiration $(V)$.
$R$. Insects possess a network of tubes called tracheal tubes for gas exchange $(IV)$.
$S$. Aquatic arthropods and molluscs use gills for respiration in water $(I)$.
$T$. Terrestrial arthropods and molluscs use vascularized structures like lungs or book lungs for respiration $(III)$.
Therefore,the correct sequence is $(P-II), (Q-V), (R-IV), (S-I), (T-III)$.

(D) The respiratory organs in animals vary based on their habitat and level of organization:
$1$. Fishes $(P)$ respire through gills $(II)$ as they are aquatic.
$2$. Reptiles,birds,and mammals $(Q)$ are terrestrial vertebrates that primarily use lungs $(I)$ for respiration.
$3$. Amphibians like frogs $(R)$ use both lungs and moist skin $(III)$ for gas exchange.
Therefore,the correct matching is $(P-II), (Q-I), (R-III)$.

(C) Statement $C$ is correct because terrestrial organisms,such as mammals,birds,and reptiles,primarily use lungs for the exchange of gases.
Statement $A$ is incorrect because $O_2$ is not used to 'directly' break down molecules; rather,it is the final electron acceptor in the electron transport chain during aerobic respiration to facilitate the complete oxidation of glucose.
Statement $B$ is incorrect because earthworms respire through their moist skin (cutaneous respiration),not through tracheal tubes.
Statement $D$ is incorrect because insects use a network of tracheal tubes for respiration,not their cuticle.

(D) The respiratory system of birds is highly efficient and unique due to the presence of air sacs.
Birds possess lungs that are connected to a system of nine air sacs that extend into the bones and other parts of the body.
These air sacs do not participate in gas exchange directly but act as bellows to ensure a continuous,unidirectional flow of air through the lungs,allowing for efficient oxygen uptake even at high altitudes.

(C) Frogs exhibit three types of respiration: cutaneous,pulmonary,and buccopharyngeal.
$1$. Cutaneous respiration occurs through the skin. This is the only mode of respiration that continues throughout the life of the frog,both on land and in water.
$2$. Pulmonary respiration occurs through the lungs,which is used primarily on land.
$3$. Buccopharyngeal respiration occurs through the lining of the mouth cavity.
$4$. Gills are typically present only in the larval stage (tadpole) and are not a mode of respiration in adult frogs.
Therefore,cutaneous respiration is the constant mode of respiration.

(B) The correct matching is as follows:
$1$. Spider: Respires through $b$. Book lungs.
$2$. Coelenterates: Respire through $c$. Plasma membrane (general body surface).
$3$. Frog: Respires through $d$. Lungs (also skin and buccal cavity).
$4$. Fishes: Respire through $a$. Internal gills.
Therefore,the correct sequence is $1-b, 2-c, 3-d, 4-a$.

(A) The correct matching is as follows:
$i$. Sponges: They respire through their body surface via the plasma membrane $(b)$.
$ii$. Insects: They possess a network of tubes called tracheae for respiration $(c)$.
$iii$. Limulus (King crab): They respire using book gills $(d)$.
$iv$. Amphibian tadpoles: They respire using external gills $(a)$.
Therefore,the correct match is $i-b, ii-c, iii-d, iv-a$.

(C) The correct matching is as follows:
$1$. Planaria: These are flatworms that respire through their $c$. Body surface via simple diffusion.
$2$. Limulus: Also known as the horseshoe crab,it respires using $a$. Book gills.
$3$. Turtles: These reptiles respire using $d$. Cloaca (in addition to lungs,they use the cloacal lining for gas exchange while submerged).
$4$. Amphibian tadpoles: These aquatic larval stages of amphibians respire using $b$. External gills.
Therefore,the correct sequence is $i-c, ii-a, iii-d, iv-b$.

(C) The correct matching is as follows:
$A$. Newts and tadpoles respire through $II$. External gills.
$B$. Platyhelminthes (flatworms) respire through $III$. Body surface (diffusion).
$C$. Reptiles respire through $IV$. Lungs.
$D$. Protists respire through $I$. Plasma membrane (diffusion).
Thus,the correct sequence is $A-II, B-III, C-IV, D-I$.

(B) Fishes are aquatic organisms that primarily use gills for respiration.
These gills are located internally within the branchial chambers,protected by an operculum in bony fishes or gill slits in cartilaginous fishes.
Therefore,fishes possess internal gills to facilitate the exchange of gases in an aquatic environment.

(A) The correct answer is $A$ (arthropods).
Respiratory organs such as gills,book gills,book lungs,and trachea are characteristic features found in the phylum $Arthropoda$.
These diverse respiratory structures allow arthropods to adapt to various environments,including aquatic and terrestrial habitats.

(D) . Molluscs generally use gills (branchial) for respiration $(A-II)$.
$B$. Reptiles rely on pulmonary respiration $(B-I)$.
$C$. Adult amphibians use both lungs (pulmonary) and skin (cutaneous) $(C-IV)$.
$D$. Amoeba,being unicellular,relies on diffusion across the cell membrane,which is a form of cellular respiration $(D-III)$.
Therefore,the correct matching is $A-II, B-I, C-IV, D-III$. Note: Based on the provided options,option $(4)$ is the closest intended answer,though the scientific match for Molluscs is Branchial $(II)$.