NEET Biology Animal Kingdom MCQs Set 04

Answer: (c) There is no need of classification now as over a million species of animals have been described till now

Explanation:
1. The correct option is (3) There is no need of classification now as over a million species of animals have been described till now.
2. In kingdom animalia, till now over a million species have been described. Animalia is largest kingdom, with over 1.2 million members. Due to such large number of member species, the need for classification becomes more important.

Teacher's Note:
1. Link this question to the matching NCERT topic and revise it.
2. The point to remember: There is no need of classification now as over a million species of animals have been described till now.

Answer: (c) Annelida – Organ level only

Explanation:
1. The correct option is (3) Annelida – Organ level only.
2. (1) Porifera – Cellular level (2) Cnidaria – Tissue level (3) Annelida – Organ-system level (4) Mollusca – Organ-system level.

Teacher's Note:
1. Link this question to the matching NCERT topic and revise it.
2. The point to remember: Annelida – Organ level only.

Answer: (b) Two openings, one as mouth and other as anus

Explanation:
1. The correct option is (2) Two openings, one as mouth and other as anus.
2. Digestive tract with two openings, mouth for ingestion and anus for egestion is known as complete digestive system.

Teacher's Note:
1. Link this question to the matching NCERT topic and revise it.
2. The point to remember: Two openings, one as mouth and other as anus.

Answer: (d) Blood circulates through a series of vessels of varying diameters

Explanation:
1. The correct option is (4) Blood circulates through a series of vessels of varying diameters.
2. Closed circulatory system is a type of blood vascular system in which blood flows inside blood vessels of varying diameter (arteries, veins, capillaries) without coming in direct contact with body cells. Closed circulatory system is observed in annelids, cephalopod molluscs, chordates.

Teacher's Note:
1. Link this question to the matching NCERT topic and revise it.
2. The point to remember: Blood circulates through a series of vessels of varying diameters.

Answer: (c) Open circulatory system

Explanation:
1. The correct option is (3) Open circulatory system.
2. Balanoglossus – Belongs to phylum Hemichordata. Anopheles – Belongs to phylum Arthropoda Laccifer – Belongs to phylum Arthropoda Both Hemichordate and Arthropoda have open circulatory system, without any exception.

Teacher's Note:
1. Link this question to the matching NCERT topic and revise it.
2. The point to remember: Open circulatory system.

Answer: (b) a(iv), b(v), c(ii), d(iii), e(i)

Explanation:
1. The correct option is (2) a(iv), b(v), c(ii), d(iii), e(i).
2. a. Limulus – King crab – Living fossil b. Ophiura – Brittle star – Phylum Echinodermata c. Taenia – Tapeworm – Phylum Platyhelminthes d. Meandrina – Brain coral – Class Anthozoa, Phylum – Cnidaria e. Dentalium – Tusk shell – Class Scaphopoda, Phylum – (Classification of Animals) Phylum : Porifera.

Teacher's Note:
1. Link this question to the matching NCERT topic and revise it.
2. Check every option separately before choosing a combined answer.

Answer: (b) An undifferentiated layer present between ectoderm and endoderm

Explanation:
1. The correct option is (2) An undifferentiated layer present between ectoderm and endoderm.
2. In diploblastic animals, developing embryo has only two germinal layers i.e. external ectoderm and internal endoderm. Mesoderm layer is not present between ectoderm and endoderm but an undifferentiated, jelly like layer is present between them. This undifferentiated layer is called Mesoglea. Mesoglea Ectoderm Endoderm Germinal layers in diploblastic animals.

Teacher's Note:
1. Link this question to the matching NCERT topic and revise it.
2. The point to remember: An undifferentiated layer present between ectoderm and endoderm.

Answer: (a) Canal system

Explanation:
1. The correct option is (1) Canal system.
2. Canal system is peculiar property of sponges where canal system is a system of interconnected chambers, canals and their openings. Also water vascular system is peculiar property of Echinoderms. Central gastrovascular cavity is property of cnidarians. Bioluminescence is property of ctenophora.

Teacher's Note:
1. Link this question to the matching NCERT topic and revise it.
2. The point to remember: Canal system.

Answer: (b) Sycon

Explanation:
1. The correct option is (2) Sycon.
2. Choanocytes or collar cells are characteristic cells of porifers/sponges. In sponges, canal and spongocoel are internally lined by choanocytes. In options, Physalia belongs to cnidaria/coelenterata. Sycon belongs to porifera/sponges. Pleurobrachia belongs to ctenophora. Echinus is a sea-urchins and belongs to Echinodermata.

Teacher's Note:
1. Link this question to the matching NCERT topic and revise it.
2. The point to remember: Sycon.

Answer: (a) Spongin fibres and spicules

Explanation:
1. The correct option is (1) Spongin fibres and spicules.
2. In porifera skeleton is made by two types of cells.  Scleroblast : They secrete spicules. In calcareous sponges, they are called calcoblast and in silicious sponges, they are called silicoblast.  Spongioblast : They secrete spongin fibre of mesohyal layer in sponges.

Teacher's Note:
1. Link this question to the matching NCERT topic and revise it.
2. The point to remember: Spongin fibres and spicules.

Answer: (d) Ostia

Explanation:
1. The correct option is (4) Ostia.
2. Sponges are also called as porifera, means pore bearing animals. Sponges have perforated body with numerous opening called ostia. Through ostia water enters inside sponges. A larger opening through which water flows out of sponge is called osculum. So porifera have enumerate mouth like pore called ostia for entry of water and single large pore for exit of water called osculum.

Teacher's Note:
1. Link this question to the matching NCERT topic and revise it.
2. The point to remember: Ostia.

Answer: (d) They have an extracellular type of digestion

Explanation:
1. The correct option is (4) They have an extracellular type of digestion.
2. Sponges are hermaphrodite i.e. male and female gamete is produced by same individual. Most of sponges are marine and asymmetric animals. Both sexual and asexual reproduction occur in them. Sponges have intracellular digestion as food is digested with in food vacuoles inside the cells. There is no extracellular digestion in sponges. Phylum : Coelenterata.

Teacher's Note:
1. Link this question to the matching NCERT topic and revise it.
2. The point to remember: They have an extracellular type of digestion.

Answer: (a) Digestion of food

Explanation:
1. The correct option is (1) Digestion of food.
2. Cnidoblast are stinging cells of phylum cnidaria/ctenophora. Projecting cnidoblast act as organ for offence and defense.  Cnidoblast help in capturing the prey by coiling around the prey.  Cnidoblast protect cnidarian by either paralyzing or killing other animal with help of toxin and spines.  Cnidoblast secrete sticky substances which provide anchorage for locomotion.

Teacher's Note:
1. Link this question to the matching NCERT topic and revise it.
2. The point to remember: Digestion of food.

Answer: (b) Radially symmetric animals

Explanation:
1. The correct option is (2) Radially symmetric animals.
2. Coelenterates are radially symmetric animals. In radially symmetric animals any plane passing through centre, divide organism in two identical halves.

Teacher's Note:
1. Link this question to the matching NCERT topic and revise it.
2. The point to remember: Radially symmetric animals.

Answer: (c) Both extracellular and intracellular

Explanation:
1. The correct option is (3) Both extracellular and intracellular.
2. Digestion is both extracellular as well as intracellular in cnidaria. Firstly there is extracellular digestion in gastrovascular cavity and then intracellular digestion involving gastrodermal muscular endothelial cells.

Teacher's Note:
1. Link this question to the matching NCERT topic and revise it.
2. Check every option separately before choosing a combined answer.

Answer: (b) They may be aquatic or terrestrial

Explanation:
1. The correct option is (2) They may be aquatic or terrestrial.
2. All cnidarians possess aquatic habitat. They are not terrestrial animals. Phylum : Ctenophora.

Teacher's Note:
1. Link this question to the matching NCERT topic and revise it.
2. The point to remember: They may be aquatic or terrestrial.

Answer: (c) Ctenophores, Cnidarians

Explanation:
1. The correct option is (3) Ctenophores, Cnidarians.
2. Comb jellies belong to phylum ctenophora. Comb jellies bear eight median comb plates. These comb plates bear cillia which fuses to form ciliated plates, giving them comb like appearance. Jelly fishes belong to phylum cnidaria.

Teacher's Note:
1. Link this question to the matching NCERT topic and revise it.
2. The point to remember: Ctenophores, Cnidarians.

Answer: (d) Locomotion

Explanation:
1. The correct option is (4) Locomotion.
2. Pleurobrachia (Sea gooseberry) belongs to phylum ctenophora. Ctenophores bear eight median comb plates. These comb plates bear cilia which are fused to make these plates ciliated. The ciliated comb plates help in locomotion.

Teacher's Note:
1. Link this question to the matching NCERT topic and revise it.
2. The point to remember: Locomotion.

Answer: (b) Multicellular with radially symmetrical body

Explanation:
1. The correct option is (2) Multicellular with radially symmetrical body.
2. Ctenoplana belong to phylum ctenophora. Ctenophores are multicellular animals, which are radially symmetric and have tissue level of organization.

Teacher's Note:
1. Link this question to the matching NCERT topic and revise it.
2. The point to remember: Multicellular with radially symmetrical body.

Answer: (a) Ctenophora

Explanation:
1. The correct option is (1) Ctenophora.
2. Bioluminescence is property of production and emission of light by a living organism. This property is well maked in ctenophores. Most ctenophores emit light by special light producing cells called photocytes. Phylum : Platyhelminthes, Aschelminthes.

Teacher's Note:
1. Link this question to the matching NCERT topic and revise it.
2. The point to remember: Ctenophora.

Answer: (c) Flame cells

Explanation:
1. The correct option is (3) Flame cells.
2. Flame cells are specialised cells of platyhelminthes which help in excretion as well as osmoregulation. Flame cells are named so, because of their flickering flame like appearance. Flame cells are also called protonephridia.

Teacher's Note:
1. Link this question to the matching NCERT topic and revise it.
2. The point to remember: Flame cells.