Chapter 4: Animal Kingdom Assertion-Reason Questions | biology Class 11 CBSE

Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 1

Logic Check

Assertion (A): Sponges are called acoelomates. Reason (R): Sponges have cellular level of organisation and lack a true body cavity lined by mesoderm.

Reasoning Options

ByteNotes

Assertion-Reason

Easy difficulty • Check the statement and reason

Easy

Question 2

Logic Check

Assertion (A): Coelenterates exhibit tissue level of organisation. Reason (R): In coelenterates, cells performing the same function are grouped together to form tissues.

Reasoning Options

ByteNotes

Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 3

Logic Check

Assertion (A): Earthworms are hermaphrodites but cross-fertilisation is the norm. Reason (R): Earthworms belong to Class Annelida where all members are dioecious.

Reasoning Options

ByteNotes

Assertion-Reason

Easy difficulty • Check the statement and reason

Easy

Question 4

Logic Check

Assertion (A): Arthropoda is the most species-rich phylum in the Animal Kingdom. Reason (R): Over two-thirds of all named species on Earth are arthropods.

Reasoning Options

ByteNotes

Assertion-Reason

Easy difficulty • Check the statement and reason

Easy

Question 5

Logic Check

Assertion (A): Chondrichthyes must swim continuously to avoid sinking. Reason (R): Chondrichthyes lack an air bladder to regulate buoyancy.

Reasoning Options

ByteNotes

Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 6

Logic Check

Assertion (A): All chordates are vertebrates. Reason (R): Vertebrata is one of the three subphyla of Chordata; the other two are Urochordata and Cephalochordata, which lack a vertebral column.

Reasoning Options

ByteNotes

Assertion-Reason

Hard difficulty • Check the statement and reason

Hard

Question 7

Logic Check

Assertion (A): Echinoderms are the only animals that are radially symmetrical as adults but bilaterally symmetrical as larvae. Reason (R): The larval bilateral symmetry in echinoderms reflects their evolutionary origin from bilaterally symmetrical ancestors.

Reasoning Options

ByteNotes

Assertion-Reason

Easy difficulty • Check the statement and reason

Easy

Question 8

Logic Check

Assertion (A): Platyhelminthes are triploblastic animals. Reason (R): In Platyhelminthes, the developing embryo has three germinal layers: ectoderm, mesoderm, and endoderm.

Reasoning Options

ByteNotes

Assertion-Reason

Hard difficulty • Check the statement and reason

Hard

Question 9

Logic Check

Assertion (A): Birds are homoiothermous animals. Reason (R): Birds can maintain a constant body temperature because they have a four-chambered heart and air sacs for efficient respiration.

Reasoning Options

ByteNotes

Assertion-Reason

Easy difficulty • Check the statement and reason

Easy

Question 10

Logic Check

Assertion (A): Aschelminthes are pseudocoelomates. Reason (R): In Aschelminthes, the body cavity is not lined by mesoderm; instead mesoderm is present as scattered pouches between ectoderm and endoderm.

Reasoning Options

ByteNotes

Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 11

Logic Check

Assertion (A): Notochord in Vertebrata is persistent throughout the life of the animal. Reason (R): In adult vertebrates, the notochord is replaced by a cartilaginous or bony vertebral column.

Reasoning Options

ByteNotes

Assertion-Reason

Easy difficulty • Check the statement and reason

Easy

Question 12

Logic Check

Assertion (A): Digestion in sponges is intracellular. Reason (R): Sponges have cellular level of organisation and lack specialised digestive organs or a gastrovascular cavity.

Reasoning Options

ByteNotes

Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 13

Logic Check

Assertion (A): Amphibians are completely independent of water for reproduction. Reason (R): Amphibians have internal fertilisation and lay eggs with protective shells on land.

Reasoning Options

ByteNotes

Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 14

Logic Check

Assertion (A): Crocodiles are more advanced than other reptiles in terms of cardiac organisation. Reason (R): Crocodiles have a completely four-chambered heart, ensuring complete separation of oxygenated and deoxygenated blood, unlike the three-chambered heart of most reptiles.

Reasoning Options

ByteNotes

Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 15

Logic Check

Assertion (A): The mantle cavity in Mollusca serves only for respiration. Reason (R): The feather-like gills present in the mantle cavity have both respiratory and excretory functions.

Reasoning Options

ByteNotes

Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 16

Logic Check

Assertion (A): Hemichordata was earlier considered a sub-phylum of Chordata. Reason (R): Hemichordates possess a stomochord in the collar region, which is structurally similar to the notochord of chordates.

Reasoning Options

ByteNotes

Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 17

Logic Check

Assertion (A): Ctenophores are diploblastic and reproduce only sexually. Reason (R): Ctenophores have sexes that are not separate and fertilisation is external with indirect development.

Reasoning Options

ByteNotes

Assertion-Reason

Hard difficulty • Check the statement and reason

Hard

Question 18

Logic Check

Assertion (A): In Annelida, the circulatory system is of the open type. Reason (R): In annelids, blood is circulated through a series of vessels including arteries, veins, and capillaries.

Reasoning Options

ByteNotes

Assertion-Reason

Easy difficulty • Check the statement and reason

Easy

Question 19

Logic Check

Assertion (A): Mammalia is the only vertebrate class in which young ones are nourished by milk. Reason (R): Mammary glands are the most unique mammalian characteristic, present in all members of the class.

Reasoning Options

ByteNotes

Assertion-Reason

Easy difficulty • Check the statement and reason

Easy

Question 20

Logic Check

Assertion (A): Obelia exhibits metagenesis. Reason (R): In Obelia, polyps produce medusae asexually and medusae form polyps sexually.

Reasoning Options

ByteNotes

Chapter sections

Chapter 4: Animal Kingdom | Assertion-Reason

Assertion (A): Sponges are called acoelomates. Reason (R): Sponges have cellular level of organisation and lack a true body cavity lined by mesoderm.

Assertion (A): Coelenterates exhibit tissue level of organisation. Reason (R): In coelenterates, cells performing the same function are grouped together to form tissues.

Assertion (A): Earthworms are hermaphrodites but cross-fertilisation is the norm. Reason (R): Earthworms belong to Class Annelida where all members are dioecious.

Assertion (A): Arthropoda is the most species-rich phylum in the Animal Kingdom. Reason (R): Over two-thirds of all named species on Earth are arthropods.

Assertion (A): Chondrichthyes must swim continuously to avoid sinking. Reason (R): Chondrichthyes lack an air bladder to regulate buoyancy.

Assertion (A): All chordates are vertebrates. Reason (R): Vertebrata is one of the three subphyla of Chordata; the other two are Urochordata and Cephalochordata, which lack a vertebral column.

Assertion (A): Echinoderms are the only animals that are radially symmetrical as adults but bilaterally symmetrical as larvae. Reason (R): The larval bilateral symmetry in echinoderms reflects their evolutionary origin from bilaterally symmetrical ancestors.

Assertion (A): Platyhelminthes are triploblastic animals. Reason (R): In Platyhelminthes, the developing embryo has three germinal layers: ectoderm, mesoderm, and endoderm.

Assertion (A): Birds are homoiothermous animals. Reason (R): Birds can maintain a constant body temperature because they have a four-chambered heart and air sacs for efficient respiration.

Assertion (A): Aschelminthes are pseudocoelomates. Reason (R): In Aschelminthes, the body cavity is not lined by mesoderm; instead mesoderm is present as scattered pouches between ectoderm and endoderm.

Assertion (A): Notochord in Vertebrata is persistent throughout the life of the animal. Reason (R): In adult vertebrates, the notochord is replaced by a cartilaginous or bony vertebral column.

Assertion (A): Digestion in sponges is intracellular. Reason (R): Sponges have cellular level of organisation and lack specialised digestive organs or a gastrovascular cavity.

Assertion (A): Amphibians are completely independent of water for reproduction. Reason (R): Amphibians have internal fertilisation and lay eggs with protective shells on land.

Assertion (A): Crocodiles are more advanced than other reptiles in terms of cardiac organisation. Reason (R): Crocodiles have a completely four-chambered heart, ensuring complete separation of oxygenated and deoxygenated blood, unlike the three-chambered heart of most reptiles.

Assertion (A): The mantle cavity in Mollusca serves only for respiration. Reason (R): The feather-like gills present in the mantle cavity have both respiratory and excretory functions.

Assertion (A): Hemichordata was earlier considered a sub-phylum of Chordata. Reason (R): Hemichordates possess a stomochord in the collar region, which is structurally similar to the notochord of chordates.

Assertion (A): Ctenophores are diploblastic and reproduce only sexually. Reason (R): Ctenophores have sexes that are not separate and fertilisation is external with indirect development.

Assertion (A): In Annelida, the circulatory system is of the open type. Reason (R): In annelids, blood is circulated through a series of vessels including arteries, veins, and capillaries.

Assertion (A): Mammalia is the only vertebrate class in which young ones are nourished by milk. Reason (R): Mammary glands are the most unique mammalian characteristic, present in all members of the class.

Assertion (A): Obelia exhibits metagenesis. Reason (R): In Obelia, polyps produce medusae asexually and medusae form polyps sexually.

Unlock all Assertion-Reason Questions

Practice in Quiz Mode