RBSE Solutions for Class 11 Biology Chapter 30 Classification of Nonchordata

RBSE Solutions for Class 11 Biology Chapter 30 Classification of Nonchordata

Rajasthan Board RBSE Class 11 Biology Chapter 30 Classification of Nonchordata

RBSE Class 11 Biology Chapter 30 Multiple Choice Objective Questions

Question 1.
Who first used the term protozoa
1. Elaeckel
2. Goldfuss
3. Lamark
4. Leeuwenhoek

Question 2.
Bath sponge is
1. Euspongia
2. Spongilla
3. Hippospongia
4. Pheronema

Question 3.
Tusk-like shell is
1. Nautilus
2. Limax
3. Chiton
4. Dentalium

Question 4.
Connecting link between annelida and mollusca
1. Peripatus
2. Neoplina
3. Limulus
4. Limax

Question 5.
Largest invertebrate is
1. Giant squid
2. Cuttlefish
3. Physalia
4. Balaenoptera

Question 6.
Aristotle lantern is found in
1. Star fish
2. Britle star
3. Sea urchin
4. Sea anemone

Question 7.
Shell of mollusca is secreted by
1.Foot
2. Mantle
3. Ctnidia
4. Placoid

Answers :
(1). 2
(2). 1
(3). 4
(4). 2
(5). 1
(6). 3
(7). 2

RBSE Class 11 Biology Chapter 30 Very Short Answer Questions

Question 1.
On what basis phylum protozoa is classified?
Answer :
Locomotory orgenelles

Question 2.
Which disease is caused by Entamoeba histolytica?
Answer :
Amoebiasis

Question 3.
Write the name of free living platyhelminthese.
Answer :
Planaria, catenula

Question 4.
Which is the largest phylum of Invertebrates ?
Answer :
Arthropoda

Question 5.
Which animal show “Tube-within-a tube” arrangement?
Answer :
Annelids

Question 6.
Which type of coelom is found in annelids ?
Answer :
Schizocoelom

Question 7.
Write one name of living fossil.
Answer :
Peripatus

Question 8.
Name the connecting link between annelida & arthropoda.
Answer :
Peripatus

Question 9.
Respiratory pigment haemocyanin is found in the animals of which phylum.
Answer :
Mollusca

Question 10.
The power of regeneration in colelenterates is because of which cells.
Answer :
Interstitial cells

Question 11.
Mesogloea layer is found in the animals of which phylum.
Answer :
Coelenterata

Question 12.
Animals of which subphylum of phylum arthropoda are extinct (fossilized).
Answer :
Trilobita

Question 13.
Which causes elephantiasis in human beings?
Answer :
Filariaworm

Question 14 .
In which class of protozoa, locomotory orgenelles are absent?
Answer :
Sporozoa

Question 15.
Name the respiratory organ in molluscs.
Answer :
Haemocyanin

RBSE Class 11 Biology Chapter 30 Short Answer Questions

Question 1.
On the basis of locomotory orgenelles, phylum protozoa is classified into how many classes?
Answer :
On the basis of locomotory orgenelles, the phylum protozoa is divided into 4 classes.

1. Class – Flagellata or Mastigophora
   • Locomotion is by flagella
   • Examples : Euglena, Noctiluca, Leishmania, Trichomonas, Trypnosoma etc.
2. Class – Sarcodina or Rhizopoda
   • Locomotion is by pseudopodia.
   • Examples – Amoeba, Entamoeba, Pelomyxa etc.
3. Class – Ciliata
   • Locomotion is by cilia.
   • Examples – Paramecium, Vorticella, Didineum, Balantidium, Opalina. Nyctotherus, Spirostomumetc.
4. Class – Sporozoa
   • Locomotary orgenelles are absent.
   • They are parasitic
   Examples – Plasmodium, Monocystes, Nosema etc.

Question 2.
Write four features of pseudocoelomates.
Answer :

• The body is round, elongated and pointed at both the ends. It is bounded by thick cuticle.
• Presence of pseudocoelom.
• Respiratory and blood vascular system are absent.
• The body wall includes syntitial epidermis and a muscular layer made up of congitudinal muscle cells. These cells are found in the form of four quadrants.

Question 3.
Write the name of two endoparasites & their disease caused in human beings.
Answer :

• Trypnosoma cruzi – Blood – Chagas disease
• Plasmodium vivax – RBC and Liver cells – Benign tertian malaria

Question 4.
What is “living fossil”? Give example.
Answer :
The animal which unchanged since last millions of years and is at the verge of extinction.
Example – Limulus, Peripatus.

Question 5.
Write the functions of nematoblasts in coelenterates.
Answer :
The nematoblasts help in offense, defense, locomotion and ingestion of food.

Question 6.
Name four phyla exhibiting indirect development.
Answer :
The four phyla exhibiting indirect development are Echinodermata, Porifera, Coelenterata and Nematoda.

Question 7.
Write salient features of phylum hemichordata.
Answer :

• Solitory/colonial, marine, tubiculous, free living & free swimming.
• Bilateral symmetrical, triploblastic, enterocoelic true coelomate.
• The body is divisible into proboscis, collar and trunk.
• The proboscis bears an endoskeleton called buccal diverticulum which is not homologous to the notochord.
• Alimentary canal is straight or U-shaped.
• Excretion by glomerulus found in the proboscis.
• Presence of gill slits.
• Unisexual, external fertilization and indirect development.
• The larva is called as tornaria.
• It is divided into two classes –

1. Class – Enteropheusta
   Examples : Balanoglossus (Tongue worm), Saccoglossus, Protoglossus etc.
2. Class – Pterobrauchii
   Examples – Rhabdopleura, Cephalodiscus

Question 8.
What is sexual dimorphism ? Give example.
Answer :
When male and female of a species can be identify with the help of external features.
Example – Man and Woman.

Question 9.
Give the reason why the hemichordates are kept under invertebrates.
Answer :
The proboscis bears an endoskeleton called buccal diverticulum which is not homologous to the notochord.

Question 10.
Give the names of classes of phylum Porifera and their respective examples.
Answer :

1. Class – Calcarea (Calcispongiae)
   • The skeleton is of spiculues made up of CaCO₃.
   • Examples – Leucosolenia, Syncon, Grantia, Leucilla etc.
2. Class – Hexactinillida (Hyalospongiae)
   • The skeleton is of spicules made up of silica.
   • Examples – Hyalomena, Euplectella, Pheronema etc.
3. Class Demospongiae
   • The skeleton is of sponging fibres.
   • Examples – Euspongia, Spongilla, Chalina, Cliona Spheceospongia etc.

Question 11.
Write four features of phylum Echinodermata.
Answer :

1. Presence of special tube feet which help in locomotion & respiration.
2. Presence of special “Water vascular system”. The water enters in it through a madriporite.
3. Blood vascular, respiratory and excretory systems are absent.
4. Less developed sense organs and nervous system.

RBSE Class 11 Biology Chapter 30 Essay Type Questions

Question 1.
Write the salient features, names of classes with examples of phylum mollusca.
Answer :
Phylum – Mollusca :
Gr. Mollis = Soft bodied)

General :
The animals of this phylum are soft bodied and unsegmented. The snails, mussels, cowries and other shells found at the banks of river, ponds, lakes etc. are all molluses. The term “mollusca” was coined by Johnztone (1605). According to Mayer (1953), it includes about 80,000 species.

Salient Features :

• Body is bilateral symmetrical, triploblastic, unsegmented & soft.
• Aquatic & some are amphibious, solitary, free living.
• Presence of reduce schizocoelom.
• Body is covered by soft mental.
• Presence of exoskeleton made upfo CaCO₃, which is called as shell. The shell may be internal or absent. The shell is secreted by the nacreous layer of the mantle.
• Body normally divisible into head, visceral mass and foot.
• Presence of toothed tongue called radula.
• Respiration is by gills. The amphibious forms also bear and lung-like structure.
• Blood is blue due to presence of a pigment called haemocyanin. The blood vascular system is partly open & party closed type.
• Excretion is by metanephridia or organ of Bojanus or Keber’s organ.
• Presence of simple eyes & statocyst which may be absent.
• Unisexual or bisexual, external or internal fertilization and direct or indirect development.

Classification of Phylum Mollusca :
On the basis of general characters, it is divided into 7 classes (Hyman, 1961).

1. Class – Monoplacophora
   • It is a connecting link between annelid and arthropoda.
   • The shell consists of only one valve (plate).
   • Example – Neoplina
2. Class Aplacophora
   • Absence of shell
   • Example – Neomania, chactoderma
3. Class – Poly placophora
   • The shell is made up of 8 plates.
   • Examples – Chiton, Lepidopeurus etc.
4. Class – Scaphopoda
   • The shell is tusk – shaped and open at both the ends.
   • Example – Dentalium
5. Class – Gastropoda
   • Some are amphibious
   • Body exhibits torsion, as a result the animals become asymmetrical.
   • The foot is broad & muscular.
   • The larva is called as veliger.
   • Examples – Pila, Cypraea, Doris, Aplysia, Limax, Helix etc.
6. Class – Pelecvpoda or bivalvia
   • The shell consists of two valves which remain hinged at one side.
   • The foot is plough – shaped
   • It’s larva is called as Glochidium.
   • Examples – Unio, Solen, Mytilus, Teredo, Pinctada
   
7. Class – Cephalopoda
   • The shell is external or internal or absent.
   • The foot divides to form oral arms and a funnel.
   • The oral arms are situated on the head around the mouth. Their number is 8 or 10 or many.
   • Examples – Sepia. Loigo, Octopus, Nautilus, Tethvs, Architeuthis etc.

Economic Importance of Mollusca :
The animals of phylum mollusca are of immense importance concern to food & pearl production.

• As Food – The body of many molluscs being fleshy is used as food by human beings particularly bivalians & gastropods. –
• Pearliculture – Natural pearl is an animal product and it is obtained many species of pearl oysters such as Pinctadci roding, Pinctada vulgaris, Pinctada margaritifera, mytilus etc. In India, specifically Lingha pearl is produced. The pearl is secreted by the nacreous layer of the mantle.

Chemically, the natural pearl is composed of Argonite (88 to 90%, CaCO₃), Conchiolin (3.5 to 6%, Scleroprotein, C₃₂H₉₈H₂O₁₁). Water (2-4%) & Residue (0.1 to 0.8%). First man made pearl was produced by a Japan! scientist named Tokichi Nishikawa.

Question 2.
Explain how arthropods are economically beneficial and harmful?
Answer :
Economic Importance of Phylum Arthropoda :
(A) Beneficial Importance
In phylum arthropoda, the insects are of much importance and the insects are reared at occupational level.

(i) Apiculture: The rearing of honey bees to obtain honey & wax is called as apiculture. The honey is used as food and medicine. As medicine, the honey is used to correct cough, cold, fever, ulcers etc. Two Indian species of honey bees are –

• Apis dorsata
• Apisindica

(ii) Lac Culture: The rearing of lac insect is called as lac culture. The scientific name of lac insect is Tacchardici lacca. The lac is a red coloured resin which is secreted by abdominal glands found in female lac insect. The lac is used to form coating around the female insect and the twig on which it is residing. The leading producer of lac are Jharkhand, Chhattisgarh, WB-Maharastra States of India.

(iii) Sericulture : The silk is produced by an insect called silk worm. The rearing of silk worm is called as sericulture. A different species of silk worm produces a different type of silk. The Bombyx mini produces mulberry silk and it is reared in captivity on mulberry leaves. Antheraea paphici produces tussore silk, Antheraea assama produces muga silk, Antheraea recini produces eri silk, Anther area produces oak silk. The silk thread is made up of fibroin and serisin proteins.

(iv) Prawn Farming (Shrimp fish Farming)
The prawn (Palaemon) is also called as Jhinga machhali. The prawn is a popular sea food and it is cultivated at large scale in South India. There are many species of prawn such as Fenneropenaeus indicus (Formerly Penaeus indicus), Palaemon longicornis, Penaeus monodon, metapenaeus affinis etc.

(v) Pollination of flowers :
Most of the pollination in the plants is perforbed by honey bees, bumble bees and other insects.

(vi) Edible insects – Insects are the food for many types of animals such as birds, lizards and fishes which in turn are consumed by human beings as food.

(vii) Destruction of harmful insects : Some of the members of this phylum help human beings by feeding harmful insects. For example – Dragon fly feeds on harmful misquotes.

(viii) Medicine synthesis – Blister beetle (Meloidae) is an insect of genus Lytta. It’s blood is used to synthesize cantheridine medicine which is meant for hair growth. Chochined bug (Dactylopius coats) is also called as Lahi. It is dark red in color. The dried and head insects are used to make chochineal dye. This dye is used to impart color in medicines, cough syrap, cosmetic products etc.

(B) Harmful
(i) Vector of diseases – Many insects act as vector host. The vector host transmit the parasite from one primary host to second primary host.

• Anopheles quadrimaculatis – Malaria fever
• culexpipuns – Elephantiasis
• Aedes egypti – yellow fever
• Phlabotomus argentipus brankti – Kala azar fever
• Musca domestica (House fly) – Colera, Typhoid, Diarrhea
• Cimax lectualrius (bed bug) – Typhus fever, TB
• Pediculus humanus capites (Human lice) – Typhus fever, Itching
• Glossina palpalis (Tsetse fly) – African sleeping sickness
• Xenopsylla cheopis – Plague

(ii) Pests of stored grains – Many insects destroy stored food material. Such as-

• Sitophilus oryzae (Rice weevil) – Rice
• Sitotroga cerealella (Angoumois grain moth – Many cereals
• Tribolium confusum (confused flour beetle) or Red beetle – All types flour & whole cereals.
• Podia interpunctella (Indian meal moth) – Wheat etc.
• Tragoderma granarium (Khapra beetle) – Wheat & other grains

(iii) House hold pests – Many insects destroy various household times. Such as –

• Lepisma saccharian (silver fish) – Old books cloth
• Liposcelis transvaalensis (Book louse) – Old books
• Monomorium indicum (white ant) – Wooden articles
• Mastotermes obesi (Termite) – Wooden articles.

Question 3.
Write the salient features, classes and economic importance of phylum platyhelminthese.
Answer :
Phylum – Platyhelminthese
[Gr.Platy = Flat & helminthese = Worm]
General :
The animals of this phvluni are commonly called as flat worms. They exhibit organ grade of body organization. There body is dorso-ventrally hat.

Phylum name platyhelminthese was coined by Gegenbaur (19859). It includes about 20.000 species

Salient Features :

1. Solitory, free living or parasitic, bilaterally symmetrical, triploblastic and acoelomate
2. The body is unsegmented or pseudosegmented.
3. The body cavity is occupied by special mesenchyma or parenchyma tissues Hence, they are called as acoelomate.
4. The alimentary canal is absent or incomplete.
5. Presence of cilia or suckers or hooks & suckers both.
6. Excretion is by flame cells.
7. Respiration is normally anaerobic.
8. Absence of respiratory, blood vascular and sensory systems.
9. Unisexual or bisexual, internal fertilization and direct or indirect development.
10. Most of them exhibit polyembryony and embryogenesis
11. Presence of special vitelline glands which secrete yolk.

Classification of Platyheminthese :
It is classified into three classes on the basis of general features –

1. Class – Turbellaria
   • Free living, aquatic (both marine & fresh water), free swimming, direct development, incomplete alimentary canal, unsegmented body.
   • Example – Planaria, Gunda, Aphronta. Catenula, Convoluta.
2. Class – Trematoda
   • Both ecto and endoparasites. Unsegmented body. Presence of suckers on the body (normally two), Alimentary canal is incomplete, exhibit polyembryony & embryogenesis.
   • Example – Fasciola, Schistosoma, Paragonimus etc.
3. Class – Cestoda
   • All the members are endoparasites, alimentary canal is absent.
   • Pseudosegmented body, presence of both hooks and suckers. The body segments are called as proglottids.
   • Example – Taenia, Echinococcus, Diphylobothrium, Hyemolepis etc.

Economic Importance of Platyhelminthese :
This phylum is important in the view that they are pathogen in human beings and other animals. The account is given in table 30.2.

Table 30.2: Showing main pathogens of phylum platyhelminthese

Question 4.
Classify the phylum protozoa on the basis of locomotory orgenelles and explain its economic importance with examples.
Answer :
Phylum – protozoa
Arthropoda, Mollusca and Echinodermata.
[Gr. Protos ⇒ First and Zoon ⇒ Animal]
General :
They are the most primitive & simplest animals. Structurally, they are acellular (unicellular) and eukaryotic. There are about  15,000 protozoan species in the world.

They were first studied by Leeuwenhoek (1677) and he names them as animalcules. The term protozoa was coined by Goldfuss (1818).

Salient Features :

1. They are simplest, unicellular and microscopic, (size ranging 0.001 to 3.0 mm).
2. They are parasitic or commensal or symbiont.
3. Mostly solitary but some are colonial.
4. They exhibit protoplasmic grade of organization.
5. Their body is naked or bounded by thin covering called pellicle.
6. They perform all the vital activities in one cell. Hence, they are called as acellular or noncellular.
7. They are mostly unicucleated but they may be binucleated or multinucleated.
8. Presence of pseudopodia or cilia or flagella for locomotion. Some are without locomotory orgenelles.
9. They are mostly holozoic (zootrophic) in nutrition but some are holophytic or saprozoic or parasitic.
10. Respiration and Excretion by diffusion through the body surface.
11. Presence of contractile vacuole (one or two) for osmorgulation primarily.
12. Asexual reproduction is by binary fission or multiple fission or budding. Some exhibit conjugation (a simple type, of sexual reproduction).
13. Some exhibit encystment.
14. They have power of regeneration.
15. Their unicellular body can’t be divided into somatoplasm and germplasm, and they never exhibit natural death. Hence, they are called as immortal.

Classification of Protozoa :
On the basis of locomotory orgenelles, the phylum protozoa is divided into 4 classes.

1. Class – Flagellata or Mastigophora
   • Locomotion is by flagella
   • Examples : Euglena, Noctiluca, Leishmania, Trichomonas, Trypnosoma etc.
2. Class – Sarcodina or Rhizopoda
   • Locomotion is by pseudopodia.
   • Examples – Amoeba, Entamoeba, Pelomyxa etc.
3. Class – Ciliata
   • Locomotion is by cilia.
   • Examples – Paramecium, Vorticella, Didineum, Balantidium, Opalina, Nvctotherus, Spirostomumete.
4. Class – Sporozoa
   • Locomotary orgenelles are absent.
   • They are parasitic
   • Examples – Plasmodium, Monocvstis, Nosema etc.

Economic Importance of Protozoa :
They are microscopic and simple still they are of much important.
(A) Beneficial Importance

1. Many protozoans inhabit dirty water and faeces. Such protozoans decompose these wastes to obtain nourishment and in turn protect from many diseases.
2. Many protozoans inhabit ponds and other freshwater bodies. They feed organic material and make the water clean & drinkable.
3. These animals being unicellular are used in the laboratories by the students to study variations. origin, evolution, hereditary of the animals.

(B) Harmful Importance
Many species of protozoans cause various diseases in human beings which are enlisted in Table 30.1.