Q: Which of the following option is correct?\$(1)\$Osteichthyes\$4\$ pairs of gills covered by an operculum\$(2)\$Chondrichthyes\$6-15\$ pairs of gill slits\$(3)\$ArthropodaMetamerism and excretion by nephridia\$(4)\$PlatyhelminthesBilateral symmetry & coelomate e.g., Taenia and Fasciola

\$\textbf{Correct option: A}\$\$\textbf{Solution:}\$\$\textbf{Explanation for correct option:}\$Option A:\$\bullet\$ Osteichthyes is a class having bony fishes i.e. their skeletal system is majorly made up of bone tissue.\$\bullet\$ These fishes have four pairs of gills covered by an operculum.\$\textbf{Explanation for incorrect options:}\$Option B:\$\bullet\$ Chondrichthyes are the class of cartilaginous fishes i.e. their endoskeleton is made up of cartilage.\$\bullet\$ They have four-five pairs of gill slits which are not covered with the operculum.Option C:\$\bullet\$ Arthropoda is the phylum of kingdom Animalia and it contains all types of insects.\$\bullet\$ Metamerism is the characteristic of segmentation of the body into different metameres. It is found in annelids, arthropods, and chordates.\$\bullet\$ But excretion through nephridia is the characteristic of only annelids. Nephridial are the coiled tubular structures present all over the skin of annelids (earthworm) through which metabolic waste is excreted out of their body.Option D:\$\bullet\$ Platyhelminthes are commonly known as flatworms.\$\bullet\$ They have a flat body that can be divided into two equal halves by a single plane, thus, they possess bilateral symmetry.\$\bullet\$ Coelomate organisms possess a body cavity called coelom. But Platyhelminthes have a flat body so, they do not possess any body cavity. That means they are acoelomates.\$\bullet\$ Both \$Taenia\$ and \$Fasciola\$ are the examples of Platyhelminthes.Hence the correct option is option A.

Question 1

In mammals and birds, why it is necessary to separate oxygenated and deoxygenated blood?

Accepted Answer

The circulatory system in birds and mammals consists of oygenated and deoxydenated blood. However, they have a double circulation system where the oxygenated as well as deoxygenated blood remain separate. This is essential to maintain the body temperature efficiently over a wide range. As mammals and birds require to keep their body warm, they require a higher supply of oxygen. Thus, it is beneficial if the oxygenated blood remains separate as its mixing with deoxygenated blood can make the entire blood impure.

Question 2

List out the differences between class-Chondrichthyes and class Osteichthyes.

Accepted Answer

Class- Chondrichthyes Class- Osteichthyes 1. The mouth is positioned ventrally and the body is covered with placoid scales. 1. The mouth is positioned apically and body is covered with cycloid or ctenoid or ganoid scales 2. Gill slits, usually five pairs, open sepa&#173;rately and directly to the exterior. 2. Gill slits, usually four pairs, open in a gill chamber. 3. The endoskeleton is cartilaginous. 3. The endoskeleton is bony with amphicoelous vertebrae. 4. Operculum always absent.Examples- Sharks and chimaeras. 4. Operculum with branchiostegal mem&#173;brane always present.Examples- Lungfish and coelacanth

Question 3

What are the characteristics features of mammals?

Accepted Answer

Characteristics features of mammals:(1) Body is covered with hair.(2) Skin is provided with sweat and sebaceous glands.(3) Heart is four chambered.(4) Fertilization is internal.(5) Females have mammary glands to produce milk to nourish their young ones.(6) External ear-pinna present.(7) Eyes have eye lids.(8) Warm-blooded.(9) Respiration through lungs.(10) Body cavity dividedinto thorax and abdomen by muscular diaphragm.

Question 4

Give characters of class mammalia.

Accepted Answer

General characteristics of class mammalia: These animals are warm blooded, hairy and have mammary or milk producing glands, (mammary glands). They are the only animals which nourish their young ones with milk. They are homoiothermous (warm blooded).Oil glands (sebaceous glands) and sweat glands (sudoriferous glands) are present in the skin.Teeth are of different types (heterodont) and are embedded in the sockets of jaws (the codont).  The heart is four chambered.

Question 5

Which of the following is correctly matched?

Accepted Answer

Correct Option: CExplanation:Autotomy, also called self-amputation, is the ability by which an organism can cast off a part of its body when in threat or danger.House lizards can break off their tail when grasped by a predator.Butterflies have adaptations like modification in wing colors that help&#10;them escape from predators. The wing colour gives the predators fear that they&#10;contain some toxic substances.Garden Lizards can change their colour according to the surrounding to&#10;camouflage from predators.Hence, the correctly matched pair is: House lizard -Autotomy.

Question 6

Which of the following option is correct?$(1)$Osteichthyes$4$ pairs of gills covered by an operculum$(2)$Chondrichthyes$6-15$ pairs of gill slits$(3)$ArthropodaMetamerism and excretion by nephridia$(4)$PlatyhelminthesBilateral symmetry & coelomate e.g., Taenia and Fasciola

Accepted Answer

$\textbf{Correct option: A}$$\textbf{Solution:}$$\textbf{Explanation for correct option:}$Option A:$\bullet$ Osteichthyes is a class having bony fishes i.e. their skeletal system is majorly made up of bone tissue.$\bullet$ These fishes have four pairs of gills covered by an operculum.$\textbf{Explanation for incorrect options:}$Option B:$\bullet$ Chondrichthyes are the class of cartilaginous fishes i.e. their endoskeleton is made up of cartilage.$\bullet$ They have four-five pairs of gill slits which are not covered with the operculum.Option C:$\bullet$ Arthropoda is the phylum of kingdom Animalia and it contains all types of insects.$\bullet$ Metamerism is the characteristic of segmentation of the body into different metameres. It is found in annelids, arthropods, and chordates.$\bullet$ But excretion through nephridia is the characteristic of only annelids. Nephridial are the coiled tubular structures present all over the skin of annelids (earthworm) through which metabolic waste is excreted out of their body.Option D:$\bullet$ Platyhelminthes are commonly known as flatworms.$\bullet$ They have a flat body that can be divided into two equal halves by a single plane, thus, they possess bilateral symmetry.$\bullet$ Coelomate organisms possess a body cavity called coelom. But Platyhelminthes have a flat body so, they do not possess any body cavity. That means they are acoelomates.$\bullet$ Both $Taenia$ and $Fasciola$ are the examples of Platyhelminthes.Hence the correct option is option A.

Question 7

Match the following :(a) Operculum           (i) Ctenophora                               (b) Parapodia            (ii) Mollusca(c) Comb plates        (iii) Porifera(d) Radula                 (iv) Reptilia(e) Hairs                    (v) Annelida(f) Choanocytes        (vi) Cyclostomata and Chondrichthyes(g) Gill slits              (vii) Mammalia(h) Scales                 (viii) Osteichthyes

Accepted Answer

Column I                         Column II(a) Operculum                (viii) Osteichthyes(b) Parapodia                 (v) Annelida(c) Comb plates             (i) Ctenophora(d) Radula                      (ii) Mollusca(e) Hairs                         (vii) Mammalia(f) Choanocytes             (iii) Porifera(g) Gill slits                     (vi) Cyclostomata and Chondrichthyes(h) Scales                       (iv) Reptilia

Question 8

Differentiate between cartilaginous fishes and bony fishes.

Accepted Answer

CARTILAGINOUS FISHES BONY FISHES 1) Their endoskeleton is primarily made of cartilage.1) Their endoskeleton is entirely made of bone.  2) Their exoskeleton is made of placoids.2) Their exoskeleton is made up of cycloids or thin bony plates.  3) The position of their tail is heterocercal.3) Their tail fin is homocercal. 4) They have 5 gills that are overly exposed (no operculum).4) They have an operculum on either side of their gills.5) In them the fertilization is through internal mechanisms.5) They fertilize their eggs externally.  6) Eg- dog fish, electric ray torpedo and sharks.6) Eg-  fying fish, globe fish and sea horses.

Question 9

Choose the correct statement.

Accepted Answer

Correct Answer: (A) Cartilaginous fish have to swim constantly to avoid sinking due to the absence of the air bladder.Explanation:Cartilaginous fishes have an air-filled bladder that helps them to maintain buoyancy.This further helps them to maintain a constant water level during swimming without any expenditure of energy.The tympanum is the organ that has the same function as that of the ear in reptiles, amphibians, and some birds.Cyclostomes are the group of fishes that don't bear any body scales but bear paired fins that are supported by the cartilaginous fin rays.There are four types of scales found in the bony fishes cosmoid, ganoid, cycloid, and ctenoid. While the cartilaginous fishes bear the placoid type of scales.Hence, option (A) is the correct statement.

Question 10

Which of the following is/are not the characteristics of the class Osteichthyes?
(i) The body is streamlined and mouth is terminal.
(ii) Gills are covered by an operculum.
(iii) Skin covered with cycloid and placoid scales.
(iv) Many of them are viviparous.

Accepted Answer

Osteichthyes are the group of bony fishes that are considered the largest group of vertebrates. They include marine and freshwater fish that has a streamlined body and the mouth is terminal. They have skin covered with cycloid, ctenoid, or genoid scales. They have four pairs of gills that are covered by an operculum on both sides. Most forms of these fishes are oviparous.Thus, the correct answer is (B).

Revise with Concepts

Class Amphibia

Class Reptilia

Class Aves

Class Mammalia

Pisces and Class Chondrichthyes and Osteichthyes

Quick Summary With Stories

The Advanced Knowledge on Aves

In mammals and birds, why it is necessary to separate oxygenated and deoxygenated blood?

List out the differences between class-Chondrichthyes and class Osteichthyes.

What are the characteristics features of mammals?

Give characters of class mammalia.

Which of the following is correctly matched?

Which of the following option is correct?
$(1)$ Osteichthyes $4$ pairs of gills covered by an operculum
$(2)$ Chondrichthyes $6 - 15$ pairs of gill slits
$(3)$ Arthropoda Metamerism and excretion by nephridia
$(4)$ Platyhelminthes Bilateral symmetry & coelomate e.g., Taenia and Fasciola

Match the following :

(a) Operculum (i) Ctenophora
(b) Parapodia (ii) Mollusca
(c) Comb plates (iii) Porifera
(d) Radula (iv) Reptilia
(e) Hairs (v) Annelida
(f) Choanocytes (vi) Cyclostomata and Chondrichthyes
(g) Gill slits (vii) Mammalia
(h) Scales (viii) Osteichthyes

Differentiate between cartilaginous fishes and bony fishes.

Choose the correct statement.

Which of the following is/are not the characteristics of the class Osteichthyes?
(i) The body is streamlined and mouth is terminal.
(ii) Gills are covered by an operculum.
(iii) Skin covered with cycloid and placoid scales.
(iv) Many of them are viviparous.

$(1)$	Osteichthyes	$4$ pairs of gills covered by an operculum
$(2)$	Chondrichthyes	$6 - 15$ pairs of gill slits
$(3)$	Arthropoda	Metamerism and excretion by nephridia
$(4)$	Platyhelminthes	Bilateral symmetry & coelomate e.g., Taenia and Fasciola

Revise with Concepts

Class Amphibia

Class Reptilia

Class Aves

Class Mammalia

Pisces and Class Chondrichthyes and Osteichthyes

Quick Summary With Stories

The Advanced Knowledge on Aves

In mammals and birds, why it is necessary to separate oxygenated and deoxygenated blood?

List out the differences between class-Chondrichthyes and class Osteichthyes.

What are the characteristics features of mammals?

Give characters of class mammalia.

Which of the following is correctly matched?

Which of the following option is correct?(1)Osteichthyes4 pairs of gills covered by an operculum(2)Chondrichthyes6−15 pairs of gill slits(3)ArthropodaMetamerism and excretion by nephridia(4)PlatyhelminthesBilateral symmetry & coelomate e.g., Taenia and Fasciola

Match the following : (a) Operculum (i) Ctenophora (b) Parapodia (ii) Mollusca(c) Comb plates (iii) Porifera(d) Radula (iv) Reptilia(e) Hairs (v) Annelida(f) Choanocytes (vi) Cyclostomata and Chondrichthyes(g) Gill slits (vii) Mammalia(h) Scales (viii) Osteichthyes

Differentiate between cartilaginous fishes and bony fishes.

Choose the correct statement.

Which of the following is/are not the characteristics of the class Osteichthyes?(i) The body is streamlined and mouth is terminal. (ii) Gills are covered by an operculum. (iii) Skin covered with cycloid and placoid scales. (iv) Many of them are viviparous.

Which of the following option is correct?
$(1)$ Osteichthyes $4$ pairs of gills covered by an operculum
$(2)$ Chondrichthyes $6 - 15$ pairs of gill slits
$(3)$ Arthropoda Metamerism and excretion by nephridia
$(4)$ Platyhelminthes Bilateral symmetry & coelomate e.g., Taenia and Fasciola

Match the following :

(a) Operculum (i) Ctenophora
(b) Parapodia (ii) Mollusca
(c) Comb plates (iii) Porifera
(d) Radula (iv) Reptilia
(e) Hairs (v) Annelida
(f) Choanocytes (vi) Cyclostomata and Chondrichthyes
(g) Gill slits (vii) Mammalia
(h) Scales (viii) Osteichthyes

Which of the following is/are not the characteristics of the class Osteichthyes?
(i) The body is streamlined and mouth is terminal.
(ii) Gills are covered by an operculum.
(iii) Skin covered with cycloid and placoid scales.
(iv) Many of them are viviparous.