Gujarat Board GSEB Textbook Solutions Class 11 Biology Chapter 4 Animal Kingdom Textbook Questions and Answers.

Gujarat Board Textbook Solutions Class 11 Biology Chapter 4 Animal Kingdom

GSEB Class 11 Biology Animal Kingdom Text Book Questions and Answers

Question 1.
What are the difficulties that you would face in the classification of animals if common fundamental features are not taken into account?
Answer:
In spite of differences in the structure of different animals, there are common fundamental features for various types of animals in relation to the arrangement of cells, body symmetry, nature of coeloms, patterns of digestive, circulatory, or reproductive systems.

These features are necessary because they help in grouping organisms with more similar traits, arrangement, and classification of animals as primitive or highly developed. It provides a basis for classification, helps in researching closely related species, etc.,

Question 2.
If you are given a specimen, what are the steps that you would follow to classify it?
Answer:
We will take the following steps:

1. Levels or grades of organization
2. Patterns in the organ system
3. Symmetry
4. Diploblastic and triploblastic organization.
5. Body cavity and coelom
6. Segmentation.

Question 3.
How useful is the study of the nature of the body cavity and coelom in the classification of animals?
Answer:
The nature of the space (body cavity) between the body wall and the alimentary canal is very important in the classification. Besides the fundamental features of the body cavity, there are many other distinctive characters, which are specific for each phylum or class. The body cavity, which is lined by mesoderm is called coelom. Animals possessing coelom are called coelomates. The animals, in which the body cavity is absent are called acoelomates. 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 pseudocolor and the animals possessing them are called pseudocode- locates.

Question 4.
Distinguish between intracellular and extracellular digestion?
Answer:
Intracellular Digestion is partly intracellular, which takes place within the gastrodermis cells. Coelenteron distributes food besides partly digesting it. Because of its dual role, the coelenteron is called the gastrovascular cavity.
Extracellular: Digestion is partly extracellular, that occurs in the coelenteron by the digestive enzymes secreted by the gastrodermis cells.

Question 5.
What is the difference between direct and indirect development?
Answer:
Direct Development: In this case the young or offsprings resembles the adult i.e., no intermediate stage ex: Humans, Birds, etc., Indirect Development: In this case the young ones when hatched or born doesn’t resemble adult but undergoes through many intermediate stages to become adult, e.g.: frogs have tadpole stage before becoming adult frogs. Butterfly have larvae, cocoon stage before becomes butterfly, etc.,

Question 6.
What are the peculiar features that you find in parasitic Platyhelminthes?
Answer:
Hooks and suckers are present in the parasitic forms. They are parasitic flatworms commonly called flukes. The body is unsegmented leaf-like, which is covered by a thick living tegument. There is no epidermis.
The mouth is anterior and is armed with suckers for attachment in the host. Life history includes a larval stage and involves more than one host.
Examples: Fasciola (the liver fluke), Schistosoma (the blood fluke).

Question 7.
What are the reasons that you can think of the arthropods to constitute the largest group of the animal kingdom?
Answer:
The following might be the reasons for the arthropods to be the largest group of the animal kingdom.

• They are the first phylum to have well-developed digestive, circulatory, Respiratory systems.
• Their body is covered by a chitinous exoskeleton which helps them survive even extreme conditions.
• They are usually small and reproduce heavily compared to all other phyla hence constitutes a higher number.
• They have highly developed sensory organs like antenna, eyes (compound and simple); statocysts, etc., which helps them keep themselves safe from predators.
• Arthropoda can be found anywhere in the world even in the volcanic springs where survival is a greater challenge, they are present in water, air and on land hence they have evolved themselves to suit all conditions.

Question 8.
Water vascular system is characteristic of which group of the following:
(a) Porifera
(b) Ctenophora
(c) Echinodermata
(d) Chordata
Answer:
(c) Echinodermata. The most distinctive feature of echinoderms is the presence of a water vascular system which helps in the locomotion, capture, and transport of food and respiration.

Question 9.
“All vertebrates are chordates but all chordates are not vertebrates.” Justify the statement.
Answer:
All chordates consist of notochord present in some stage of life. Only invertebrates this notochord present in the embryonic stage is replaced by the vertebral column during the adult stage.

Question 10.
How important is the presence of an air bladder in Pisces?
Answer:
Air bladder in Pisces regulates buoyancy. Sharks do not possess an air bladder like bony fishes. Due to this reason, they have to swim constantly else they will sink to the bottom. Bony fishes do not face such a problem.

Question 11.
What are the modifications that are observed in birds that help them fly?
Answer:
The following modification helps birds to fly:

• presence of feathers
• presence of pneumatic bones; pneumatic bones are long hollow bones (have air cavities)
• Forelimbs are modified into wings to help in flight
• hind limbs generally have scales helping them to clasp the prey in-flight or a tree branch
• Excretion of urine and feces is through single opening and excretion has very less amount of water this is to reduce body weight.
• An aerodynamically built body helps in flying.

Question 12.
Could the number of eggs or young ones produced by an oviparous and viviparous mother be equal? Why?
Answer:
In oviparous animals, the newly hatched young may resemble the adult. Such a development is called direct development. In some cases, the young hatched from eggs do not resemble the adult. These young are called larvae, nymphs, or naiad. They lead an independent life for some period and finally undergo important change to become adults. This change from larvae to adults is called metamorphosis and such a development is called indirect development. Viviparous animals produce minute eggs and the developing embryo gets its nourishment from the mother’s genital tract through the placenta e.g. mammals.

Question 13.
Segmentation in the body is first observed in which of the following:
(a) Platyhelminthes
(b) Aschelminthes
(c) Annelida
(d) Arthropoda
Answer:
(a) Platyhelminthes have a blind sac body plan. Flatworms possess ahead at the interior end. It has a brain, sense organs and remains forward during locomotion. There is a complete absence of appendages. The body surface is however ciliated. They have an organ-system level of body organization. They are dorso-ventrally flattened and commonly known as flatworms.

(b) Aschelminthes: The body of the as helminths appear circular in
cross-section, hence, the name roundworm. They may be free-living, aquatic, terrestrial, or parasitic in plants and animals. Roundworms have organ-system level of body organization

(c) Annelida: Annelids were the first segmented animals. Their body surface is distinctly marked out into segments or metameres like rings and, hence, the phylum name Annelida. The body is covered by a cuticle. The muscles present in the body wall helps in locomotion on the ground.

(d) Arthropods are bilaterally symmetrical, triploblastic, segmented, and acoelomate animals. The body of arthropods is covered by a cuticle that forms the exoskeleton. The body segments are fused to form the head, thorax, and abdomen. They have jointed appendages. The appendages are variously modified to form antennae, mouthparts, pincers (chelicerae) or
walking legs.

Question 14.
Match the following:

Answer:
(i) h
(ii) e
(iii) d
(iv) a
(v) b
(vi) g
(vii) c
(viii) f

Question 15.
Prepare a list of some animals that are found parasitic on human beings?
Answer:

• Taenia (Tapeworm)
• Fasciola (liver fluke)
• Ascaris (roundworm)
• wachereia (filaria worm)
• Ancylostoma (Hookworm)
• Hirudinaria (bloodsucking leech)