Case Study Questions Class 11 Biology Animal Kingdom

Case Study Questions Class 11 Biology Chapter 4 Animal Kingdom

CBSE Class 11 Case Study Questions Biology Animal Kingdom. Important Case Study Questions for Class 11 Board Exam Students. Here we have arranged some Important Case Base Questions for students who are searching for Paragraph Based Questions Animal Kingdom.

At Case Study Questions there will given a Paragraph. In where some Important Questions will made on that respective Case Based Study. There will various types of marks will given 1 marks, 2 marks, 3 marks, 4 marks.

CBSE Case Study Questions Class 11 Biology Animal Kingdom

CASE 1

Though all members of Animalia are multicellular, all of them do not exhibit the same pattern of organisation of cells. For example, in sponges, the cells are arranged as loose cell aggregates, i.e., they exhibit cellular level of organisation. Some division of labour (activities) occur among the cells. In coelenterates, the arrangement of cells is more complex. Here the cells performing the same function are arranged into tissues, hence is called tissue level of organisation. A still higher level of organisation, i.e., organ level is exhibited by members of Platyhelminthes and other higher phyla where tissues are grouped together to form organs, each specialised for a particular function. In animals like Annelids, Arthropods, Molluscs, Echinoderms and Chordates, organs have associated to form functional systems, each system concerned with a specific physiological function. This pattern is called organ system level of organisation. Organ systems in different groups of animals exhibit various patterns of complexities. For example, the digestive system in Platyhelminthes has only a single opening to the outside of the body that serves as both mouth and anus, and is hence called incomplete. A complete digestive system has two openings, mouth and anus. Similarly, the circulatory system may be of two types: (i) open type in which the blood is pumped out of the heart and the cells and tissues are directly bathed in it and (ii) closed type in which the blood is circulated through a series of vessels of varying diameters (arteries, veins and capillaries).

Symmetry – Animals can be categorised on the basis of their symmetry. Sponges are mostly asymmetrical, i.e., any plane that passes through the centre does not divide them into equal halves. When any plane passing through the central axis of the body divides the organism into two identical halves, it is called radial symmetry. Coelenterates, ctenophores and echinoderms have this kind of body plan. Animals like annelids, arthropods, etc., where the body can be divided into identical left and right halves in only one plane, exhibit bilateral symmetry.

1.) When two or more organs work together to perform a specific function, this pattern is called is termed as _______________.

a) Cellular Level of Organisation

b) Tissue Level of Organisation

c) Organ Level of Organisation

d) Organ System Level of Organisation

2.) Identify the correct statement

Statement 1 – In Organ System Level of Organisation each system concerned with same physiological function.

Statement 2 – In tissue level of organization each cells performing the same function arranged into tissue

Statement 3 – In tissue level of organization each cells performing the different function arranged into tissue

Statement 4 – in Organ System Level of Organisation each system concerned with specific physiological function.

a.) Statement 1 and 2 is correct

b) Statement 3 and 4 is correct

c) Statement 2 and 4 is correct

d) Statement 3 and 4 is correct

3.) Define bilateral symmetry. Give it example.

4.) What is mean by complete digestive system?

5.) Define incomplete digestive system with suitable example.

Answer key

1.) d

2.) c

3.) When any plane passing through the central axis of the body, divides body into identical left and right halves in only one plane this type of symmetry named as bilateral symmetry.

Example, Humans, arthropods.

4.) Complete digestive system – When digestive system consist of a digestive tract with two openings. One opening is the mouth. The other is the anus, such digestive system is called as complete digestive system.

For example, digestive system of humans.

5.) Incomplete digestive system – When digestive system consists of a digestive cavity with only one opening, serves as both mouth and anus, such digestive system is called as incomplete digestive system.

For example, the digestive system in Platyhelminthes has only a single opening to the outside of the body that serves as both mouth and anus, and is hence called incomplete.

CASE 2

Animals in which the cells are arranged in two embryonic layers, an external ectoderm and an internal endoderm, are called diploblastic animals, e.g., coelenterates. An undifferentiated layer, mesoglea, is present in between the ectoderm and the endoderm.

Coelom – Presence or absence of a cavity between the body wall and the gut wall is very important in classification. The body cavity, which is lined by mesoderm is called coelom. Animals possessing coelom are called coelomates, e.g., annelids, molluscs, arthropods, echinoderms, hemichordates and chordates. In some animals, the body cavity is not lined by mesoderm, instead, the mesoderm is present as scattered pouches in between the ectoderm and endoderm. Such a body cavity is called pseudocoelom and the animals possessing them are called pseudocoelomates, e.g., aschelminthes. The animals in which the body cavity is absent are called acoelomates, e.g., Platyhelminthes.

Segmentation – In some animals, the body is externally and internally divided into segments with a serial repetition of at least some organs. For example, in earthworm, the body shows this pattern called metameric segmentation and the phenomenon is known as metamerism.

Notochord – It is a mesodermally derived rod-like structure formed on the dorsal side during embryonic development in some animals. Animals with notochord are called chordates and those animals which do not form this structure are called non-chordates, e.g., porifera to echinoderms.

1.) Diploblastic animals are characterised by _________________.

a) External ectoderm cell arrangement

b) Internal endoderm cell arrangement

c) Both a and b

d) None of the above

2.) In coelomates, body cavity is surfaced by____________

a) Ectoderm

b) Mesoderm

c) scattered pouches

d) Endoderm

3.) Name the layer is present in between the ectoderm and the endoderm in diploblastic animals.

4.) What is mean by metameric segmentation and metamerism?

5.) What is Notochord?

6.) Define coelom.

Answer key

1.) c

2.) b

3.) An undifferentiated layer named as mesoglea, is present in between the ectoderm and the endoderm in diploblastic animals.

4.) In some animals, the body is externally and internally divided into segments with a serial repetition of at least some organs is called metameric segmentation. This phenomenon of metameric segmentation is known as metamerism. For example, earthworm.

5.) Notochord is a mesodermally derived rod-like structure formed on the dorsal side during embryonic development in some animals. Animals with notochord are called chordates and those animals which do not form this structure are called non-chordates, e.g., porifera to echinoderms.

6.) Presence of a cavity between the body wall and the gut wall. The body cavity, which is lined by mesoderm is called coelom. Animals possessing coelom are called coelomates, e.g., annelids, molluscs, arthropods, echinoderms, hemichordates and chordates.

CASE 3

Phylum – Porifera

Members of this phylum are commonly known as sponges. They are generally marine and mostly asymmetrical animals. These are primitive multicellular animals and have cellular level of organisation. Sponges have a water transport or canal system. Water enters through minute pores (ostia) in the body wall into a central cavity, spongocoel, from where it goes out through the osculum. This pathway of water transport is helpful in food gathering, respiratory exchange and removal of waste. Choanocytes or collar cells line the spongocoel and the canals. Digestion is intracellular. The body is supported by a skeleton made up of spicules or spongin fibres. Sexes are not separate (hermaphrodite), i.e., eggs and sperms are produced by the same individual. Sponges reproduce asexually by fragmentation and sexually by formation of gametes. Fertilisation is internal and development is indirect having a larval stage which is morphologically distinct from the adult. Examples: Sycon (Scypha), Spongilla (Fresh water sponge) and Euspongia (Bath sponge).

Phylum – Coelenterata (Cnidaria)

They are aquatic, mostly marine, sessile or free-swimming, radially symmetrical animals. The name cnidaria is derived from the cnidoblasts or cnidocytes (which contain the stinging capsules or nematocysts) present on the tentacles and the body. Cnidoblasts are used for anchorage, defense and for the capture of prey. Cnidarians exhibit tissue level of organisation and are diploblastic. They have a central gastro-vascular cavity with a single opening, mouth on hypostome. Digestion is extracellular and intracellular. Some of the cnidarians, e.g., corals have a skeleton composed of calcium carbonate. Cnidarians exhibit two basic body forms called polyp and medusa. The former is a sessile and cylindrical form like Hydra, Adamsia, etc. whereas, the latter is umbrella-shaped and free-swimming like Aurelia or jelly fish. Those cnidarians which exist in both forms exhibit alternation of generation (Metagenesis), i.e., polyps produce medusae asexually and medusae form the polyps sexually (e.g., Obelia). Examples: Physalia (Portuguese man-of-war), Adamsia (Sea anemone), Pennatula (Sea-pen), Gorgonia (Sea-fan) and Meandrina (Brain coral).

1.) Spongocoel is lined by special cells called

a.) cnidocytes

b.) Choanocytes

c.) Mesoderm

d.) Both a and b

2.) ______________ are the minute opening present on the body of sponges through which water enters in the body cavity.

a.) Cnidocytes

b.) hypostome

c.) Ostia

d.) spongocoel

3.) Define Cnidocytes. Give its function.

4.) Name the body form occurs in cnidarians with examples.

5.) What is spongocoel?

Answer key

1.) b

2.) c

3.) Cnidocytes are specialized cells that define the phylum Cnidaria.Cnidocytes contain the stinging capsules or nematocysts. It is also known as cnidoblasts.Cnidoblasts present on the tentacles and the body.

Functions –Cnidoblasts are used for anchorage, defense and for the capture of prey.

4.) Cnidarians exhibit two basic body forms – Polyp and Medusa.

  • Polyp is a sessile and cylindrical form like Hydra, Adamsia, etc.
  • Medusa is umbrella-shaped and free-swimming like Aurelia or jelly fish.

5.) Spongocoel is the internal cavity present inside the body of sponges,opens through the osculum.

CASE 4

Phylum: Ctenophora

These are commonly called comb jellies or sea walnuts. These are exclusively marine, free swimming animals. Body is diploblastic, radially symmetrical with blind-sac body plan. Animals have tissue-level organisation. Locomotion is carried out by eight rows of cilliated comb plates. Characteristic feature of ctenophores is bioluminescence. Like cnidarians, ctenophores also exhibit extra and intracellular digestion. Reproduction is sexual with indirect development. Cnidoblasts are absent hence these are called acnidarians. Instead, they have colloblasts (sticky cells) to capture the prey. Ctenophora is represented by very few members, hence it is considered as one of the minor phyla.E.g. Pleurobrachia, Ctenoplana

 

Phylum – Platyhelminthes

They have dorso-ventrally flattened body, hence are called flatworms. These are mostly endoparasites found in animals including human beings. Flatworms are bilaterally symmetrical, triploblastic and acoelomate animals with organ level of organisation. Hooks and suckers are present in the parasitic forms. Some of them absorb nutrients from the host directly through their body surface. Specialised cells called flame cells help in osmoregulation and excretion. Sexes are not separate. Fertilisation is internal and development is through many larval stages. Some members like Planaria possess high regeneration capacity. Examples: Taenia (Tapeworm), Fasciola (Liver fluke).

1.) Identify the correct statement

Statement 1 – Flatworms are triploblastic animals.

Statement 2 – Flame cellsis specialised excretory cell.

Statement 3 – Flatworms are acoelomate and shows bilaterally symmetrical.

Statement 4 – Flatworms exhibits organ level of organisation.

 

a.) Statement 1 and 3 are correct

b) Statement 1, 3 and 4 are correct

c.) Statement 2 is correct

d.) All are correct

2.) In Platyhelminthes, ___________________ plays key role in osmoregulation and excretion.

a.) colloblasts

b.) Cnidoblasts

c.) Flame cells

d.) Coelom

3.) Give reason – Why ctenophora are known as acnidarians?

4.) Name the specialised sticky cell present in ctenophora.

5.) Give any two distinguishing feature of Ctenophora.

Answer key

1.) d

2.) c

3.) In ctenophora, Cnidoblasts or Cnidocytes cells are absent, hence these are called as acnidarians.

4.) Ctenophora have specialised cells called colloblasts (sticky cells) which helps to capture the prey.

5.) Characteristic feature of ctenophores is

    • Ctenophores exhibits bioluminescence.
    • Digestion is extra and intracellular.
    • Ctenophores have colloblasts i.e. sticky cells which helps to capture pray.
    • Locomotion is carried out by eight rows of cilliated comb plates.

CASE 5

Phylum – Chordata

Animals belonging to phylum Chordata are fundamentally characterised by the presence of a notochord, a dorsal hollow nerve cord and paired pharyngeal gill slits. These are bilaterally symmetrical, triploblastic, and coelomate with organ-system level of organisation. They possess a post anal tail and a closed circulatory system.

Phylum Chordata is divided into three subphyla: Urochordata or Tunicata, Cephalochordata and Vertebrata.

Subphyla Urochordata and Cephalochordata are often referred to as protochordates and are exclusively marine. In Urochordata, notochord is present only in larval tail, while in Cephalochordata, it extends from head to tail region and is persistent throughout their life. Examples: Urochordata – Ascidia, Salpa, Doliolum; Cephalochordata – Branchiostoma (Amphioxus or Lancelet).

The members of subphylum Vertebrata possess notochord during the embryonic period. The notochord is replaced by a cartilaginous or bony vertebral column in the adult. Thus all vertebrates are chordates but all chordates are not vertebrates. Besides the basic chordate characters, vertebrates have a ventral muscular heart with two, three or four chambers, kidneys for excretion and osmoregulation and paired appendages which may be fins or limbs.

1.) Subphyla Tunicata, is characterised by ___________

a.) Presence of notochord throughout their life

b.) extend notochord from head to tail region

c.) Presence of notochord only in larval tail

d.) Both a & b

2.) Doliolum, is belongs to subphyla ___________

a.) Vertebrata

b.) Tunicata

c.) Cephalochordata

d.) Protochordates

3.) Give the characteristic feature of Cephalochordata with suitable example.

4.) What is protochordates?

5.) Give the characteristic feature of Phylum – Chordata and Enlist the name of subphyla.

6.) Give reason – why all vertebrates are chordates but all chordates are not vertebrates?

Answer key

1.) c

2.) b

3.) In Cephalochordata notochord extends from head to tail region and is persistent throughout their life.

Example: Branchiostoma (Amphioxus or Lancelet).

4.) Subphyla Urochordata and Cephalochordata are together often referred to as protochordates and are exclusively marine.

5.) Phylum Chordata are characterised by the presence of a notochord, a dorsal hollow nerve cord and paired pharyngeal gill slits. These are bilaterally symmetrical, triploblastic, and coelomate with organ-system level of organisation. They possess a post anal tail and a closed circulatory system.

Phylum Chordata is divided into three subphyla:

  • Urochordata or Tunicata
  • Cephalochordata

6.) The members of subphylum Vertebrata possess notochord during the embryonic period. In adult stage notochord is replaced by a cartilaginous or bony vertebral column in the adult. Hence all vertebrates are chordates but all chordates are not vertebrates.

Updated: April 3, 2022 — 12:56 am

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