Case study ( 4 Marks )

Question 14 Marks

Animalia are organisms which are eukaryotic, multicellular and heterotrophic. Their cells do not have cell-walls. They are further classified based on the extent and type of the body design differentiation found.
PORIFERA
Porifera means organisms with holes. These are non-motile animals attached to some solid support. There are holes or ‘pores’, all over the body, that helps in circulating water throughout the body to bring in food and oxygen. These animals are covered with a hard outside layer or skeleton. They are commonly called sponges, and are mainly found in marine habitats.
COELENTERATA
These are aquatic animals, show more body design differentiation. There is a cavity in the body. The body is made of twolayers of cells: one makes up cells on the outside of the body, and the other makes the inner lining of the body. Examples, Corals, Hydra, Jellyfish and sea anemones.
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PLATYHELMINTHES
The body is bilaterally symmetrical, triploblastic. There is no true internal body cavity or coelom. The body is flattened dorsoventrally,hence these animals are called flatworms. They are either free-living or parasitic. Examples,Planarians, Liver flukes.
NEMATODES
The nematode body is bilaterally symmetrical, triploblastic, cylindrical. There are tissues, but no real organs, although a sort of body cavity or a pseudo coelom, is present. These are very familiar as parasitic worms causing diseases.Examples, the worms in the intestines (roundworm or pinworms).
ANNELIDA
Annelid body is bilaterally symmetrical, triploblastic, have a true body cavity. This allows true organs to be packaged in the body structure. These animals are found in a variety of aquatic habitats& land. Examples, Earthworms and leeches.
ARTHROPODA
This is probably the largest group of animals. These animals are bilaterally symmetrical and segmented. There is an open circulatory system, and so the blood does not flow in well-defined blood vessels. The coelomic cavity is blood-filled. They have jointed legs.Examples Butterflies, Houseflies.
MOLLUSCA
In the animals of this group, there is bilateral symmetry. The coelomic cavity is reduced. They have an open circulatory system and kidney-like organs for excretion. There is a foot that is used for moving around. Examples are snails and mussels.
ECHINODERMATA
Echinodermata are spiny skinned organisms. These are free-living marine animals. They are triploblastic and have a coelomic cavity. They also have a peculiar water-driven tube system that they use for moving around. They have hard calcium carbonate structures that they use as a skeleton. Examples are sea-stars and sea urchins.
PROTOCHORDATA
These animals are bilaterally symmetrical, triploblastic and have a coelom. They show a new feature i.e. notochord. The notochord is a long rod-like support structure that runs along the back of the animal separating the nervous tissue from the gut. It provides a place for muscles to attach for ease of movement. Protochordates may not have a proper notochord present at all stages in their lives or for the entire length of the animal. Examples are Balanoglossus, Herdmania and Amphioxus.
(1) Which of the following is a characteristic feature of Arthropod?
$(a)$ Body is bilaterally segmented
$(b)$ They have an open circulatory system
$(c)$ They have jointed legs
(d) All of the above
(2) Which of the following is not a characteristic feature ofEchinodermata?
$(a)$ Spiny skin
$(b)$ They have an open circulatory system
$(c)$ They have coelomic cavity
$(d)$ They have calcium carbonate skeleton
(3) Which of the following areexample of Arthropod?
$(a)$ Butterflies and Houseflies.
$(b)$ Balanoglossus and Herdmania.
$(c)$ Snails and Mussels.
$(d)$ Earthworms and Leeches.
(4) Give any three characteristic feature of Protochordates?
(5) Define Notochord.

Answer

$(1)D$
$(2) B$
$(3) A$
$(4)$ Characteristic feature of Protochordates

Body is bilaterally symmetrical, triploblastic
They have a coelom.
They show a distinguishing feature i.e. notochord.
They are marine animals.

$(5)$ The notochord is a long rod-like support structure that runs along the back of the animal separating the nervous tissue from the gut. It provides a place for muscles to attach for easy of movement.

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Question 24 Marks

Vertebrates have a true vertebral column and internal skeleton, allowing a completely different distribution of muscle attachment points to be used for movement. Vertebrates are bilaterally symmetrical, triploblastic, coelomic and segmented, with complex differentiation of body tissues and organs. All chordates possess the following features, Such as they have a notochord, a dorsal nerve cord, paired gill pouches.Vertebrates are grouped into six classes.
CYCLOSTOMATA
Cyclostomes are jawless vertebrates. They have an elongated eel-like body, circular mouth, slimy skin and are scale less. They are ectoparasites or borers of other vertebrates. Example, Petromyzon (Lamprey) and Myxine
PISCES
These are fish. They are exclusively aquatic animals. Their skin is covered with scales. They obtain oxygen dissolved in water by using gills. The body is streamlined, muscular tail is used for movement. They are cold-blooded and their hearts have only two chambers, they lay eggs. Examples, tuna or rohu.
AMPHIBIA
These animals differ from the fish in the lack of scales, in having mucus glands in the skin, and a three-chambered heart. Respiration is through either gills or lungs. They lay eggs. These animals are found both in water and on land. Examples, Frogs & toads.
REPTILIA
These animals are cold-blooded, have scales and breathe through lungs. They have a three-chambered heart, crocodiles have four heart chambers. They lay eggs with tough coverings and do not need to lay their eggs in water, unlike amphibians.Examples, Snakes, turtles, lizards.
AVES
These are warm-blooded animals and have a four-chambered heart. They lay eggs. There is an outside covering of feathers, and two forelimbs are modified for flight. They breathe through lungs.
MAMMALIA
Mammals are warm-blooded animals with four-chambered hearts. They have mammary glands for the production of milk to nourish their young. Their skin has hairs as well as sweat and oil glands. However, Examples, Kangaroo.
(1) Which of the following is not a characteristic feature of Mammals?
$(a)$ Warm blooded animal
$(b)$ Four chambered heart
$(c)$ Have mammary gland
$(d)$ Skin in covered with scales
(2) Which of the following is a characteristic feature of Reptiles?
$(a)$ Cold blooded animal
$(b)$ Generally have three chambered heart
$(c)$ Have mammary gland
$(d)$ Both $a$ & $b$
(3) Which class of vertebrates are known as jawless vertebrates?
$(a)$ Amphibian
$(b)$ Aves
$(c)$ Mammalia
$(d)$ Cyclostomata
(4) Enlist the six classes of Vertebrates?
(5) Give any three characteristic feature of Aves

Answer

$(1) D$
$(2) D$
$(3) D$
$(4)$ Vertebrates are grouped into six classes

Pisces
Cyclostomata
Amphibian
Aves
Mammalia
Cyclostomata

$(5)$Characteristic feature of Aves

These are warm-blooded animals.
They have a four-chambered heart.
They lay eggs.
There is an outside covering of feathers.
Two forelimbs are modified for flight.
They breathe through lungs.

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Question 34 Marks

‘scientific’ name for organisms in the same manner that chemical symbols and formulae for various substances are used in the world. The scientific name for an organism is thus unique and can be used to identify it anywhere in the world.The system of scientific naming or nomenclature we use today was introduced by Carolus Linnaeus in the eighteenth century. The scientific name of an organism isthe process of classification which puts it along with the organisms it is most related to. But when we actually name the species, we do not list out the whole hierarchy of groups it belongs to. Instead, we limit ourselves to writing the name of the genus and species of that particular organism. World over, it has been agreed that both these names will be used in Latin forms.
Certain conventions are followed while writing the scientific names:
(1) The name of the genus begins with a capital letter.
(2) The name of the species begins with a small letter.
(3) When printed, the scientific name is given in italics.
(4) When written by hand, the genus name and the species name have to be underlined separately.
(1) The system of scientific naming or nomenclature we use today was introduced by
$(a)$ Carolus Linnaeus
$(b)$ Ernst Haeckel
$(c)$ Robert Whittaker
$(d)$ Carl Woese
(2) When scientific name is printed is given in
$(a)$ Bold
$(b)$ Italics
$(c)$ Italic in lowercase
$(d)$ Bold in uppercase
(3) Identify the correct statement
Statement $1$ – Name of the genus begins with a capital letter.
Statement $2$ – Name of the species begins with a small letter.
Statement $3$ –Name of the genus begins with a small letter
Statement $4$ –When printed, the scientific name is given in bold
$(a)$ Both $1$ & $3$
$(b)$ Both $3$ & $4$
$(c)$ Both $1$ & $2$
$(d)$ All of the above
(4) Why is there a need for systematic naming of living organisms?
(5) Which rules and conventions are need to be followed while writing the scientific names?

Answer

$(1) A$
$(2) B$
$(3) C$
$(4) A$
$(5)$ Rules to be followed while writing the scientific name

The name of the genus begins with a capital letter.
The name of the species begins with a small letter.
When printed, the scientific name is given in italics.
When written by hand, the genus name and the species name have to be underlined separately.

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Question 44 Marks

The first level of classification among plants depends on whether the plant body has well differentiated, distinct parts. The next level of classification is based on whether the differentiated plant body has special tissues for the transport of water and other substances. Further classification looks at the ability to bear seeds and whether the seeds are enclosed within fruits.
THALLOPHYTA
Plants that do not have well-differentiated body design fall in this group. The plants in this group are commonly called algae. These plantsare predominantly aquatic. Examples are Spirogyra, Ulothrix, Cladophora, Ulva and Chara.
BRYOPHYTA
These are called the amphibians of the plant kingdom. The plant body is commonly differentiated to form stem and leaf-like structures. There is no specialised tissue for the conduction of water and other substances from one part of the plant body to another. Examples are moss (Funaria) and Marchantia.
PTERIDOPHYTA
In this group, the plant body is differentiated into roots, stem and leaves and has specialised tissue for the conduction of water and other substances from one part of the plant body to another. Some examples are Marsilea, ferns. The reproductive organs of plants in all these three groups are very inconspicuous, and they are therefore called ‘cryptogams’, or ‘those with hidden reproductive organs’. On the other hand, plants with welldifferentiated reproductive parts that ultimately make seeds are calledphanerogams. This group is further classified, based on whether the seeds are naked or enclosed in fruits, giving us two groups – gymnosperms and angiosperms.
Gymnosperms are the plants which bear naked seeds and are usually perennial, evergreen and woody. Examples are pines and deodar. Angiosperms are the plants which seeds are enclosed inside an ovary.
(1) Plants that do not have well-differentiated body is known as _________
$(a)$ Bryophytes
$(b)$ Pteridophytes
$(c)$ Thallophytes
$(d)$ Angiosperms
(2) The plants which bear naked seeds
$(a)$ Angiosperms
$(b)$ Gymnosperms
$(c)$ Thallophytes
$(d)$ Pteridophytes
(3) Phanerogams are further classified into
$(a)$ Angiosperms
$(b)$ Gymnosperms
$(c)$ Thallophytes
$(d)$ Both $a$ & $b$
(4) Which of the following is the distinguishing feature of Bryophytes
$(a)$ Plant body is differentiated to form stem and leaf-like structures
$(b)$ No specialised tissue for the conduction of water and food
$(c)$ Both $a$ & $b$
$(d)$ None of above
(5) Explain the three important aspect on which classification of Plantae?

Answer

$(1) c$
$(2) b$
$(3) d$
$(4) c$
$(5)$ The first level of classification among plants depends on

Whether the plant body has well differentiated, distinct parts
Whether the differentiated plant body has special tissues for the transport of water
The ability to bear seeds and whether the seeds are enclosed within fruits

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Question 54 Marks

Biologists, such as Ernst Haeckel $(1894)$, Robert Whittaker $(1969)$ and Carl Woese $(1977)$ have tried to classify all living organisms into broad categories, called kingdoms.The classification Whittaker proposed has five kingdoms: Monera, Protista, Fungi, Plantae and Animalia, and is widely used. These groups are formed on the basis of their cell structure, mode and source of nutrition and body organisation.
The modification Woese introduced by dividing the Monera into Archaebacteria (or Archaea) and Eubacteria (or Bacteria) is also in use. Further classification is done by naming the sub-groups at various levels as given in the following scheme:
Kingdom
Phylum (for animals) / Division (for plants)
Class
Order
Family
Genus
Species
Thus, by separating organisms on the basis of a hierarchy of characteristics into smaller and smaller groups, we arrive at the basic unit of classification, which is a ‘species’. A species includes all organisms that are similar enough to breed and perpetuate.
(1) Who proposed Five Kingdoms?
$(a)$ Ernst Haeckel $(1894)$
$(b)$ Robert Whittaker $(1969)$
$(c)$ Carl Woese $(1977)$
$(d)$ None of above
(2) Which of the following kingdom is a part of five kingdom system?
$(a)$ Monera
$(b)$ Protista
$(c)$ Animalia
$(d)$ All of the above
(3) Kingdom Monera divided into
$(a)$ Archaebacteria
$(b)$ Eubacteria
$(c)$ Both $a$ & $b$
$(d)$ None of above
(4) A groups of five kingdom are formed on the basis of
$(a)$ Cell structure,
$(b)$ Mode and source of nutrition
$(c)$ Body organisation.
$(d)$ All of the above
(5) What is species?

Answer

$(1) b$
$(2) d$
$(3) c$
$(4) d$
$(5)$ By separating organisms on the basis of a hierarchy of characteristics into smaller and smaller groups, we arrive at the basic unit of classification, which is a ‘species’. A species includes all organisms that are similar enough to breed and perpetuate.

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Science Case study ( 4 Marks )

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