Mix Example - DIVERSITY IN LIVING ORGANISMS Questions in English

(A) $Monerans$ are prokaryotes,which means they do not possess a well-defined nucleus. Their genetic material is not enclosed within a nuclear membrane. Therefore,the statement that $Monerans$ have a well-defined nucleus is incorrect.

(B) Specialised conductive tissues (xylem and phloem) are absent in Thallophyta and Bryophyta.
These tissues first appear in Pteridophyta and are also present in Gymnosperms.
Therefore,Pteridophyta and Gymnosperms possess specialised tissues for the conduction of water.

(C) Plants are classified based on their ability to produce seeds.
$1$. Thallophyta,Bryophyta,and Pteridophyta are cryptogams,meaning they do not produce seeds.
$2$. Gymnosperms and Angiosperms are phanerogams,which are seed-bearing plants.
$3$. Therefore,among the given options,Gymnosperms are the only group that produces seeds.

(D) true fish belongs to the class $Pisces$ (or $Chondrichthyes$/$Osteichthyes$).
$Dogfish$ $(Scoliodon)$ is a cartilaginous fish belonging to the class $Chondrichthyes$.
$Jellyfish$ is a member of the phylum $Cnidaria$ (or $Coelenterata$).
$Starfish$ is an echinoderm belonging to the phylum $Echinodermata$.
$Silverfish$ is an insect belonging to the phylum $Arthropoda$.
Therefore,$Dogfish$ is the only true fish among the given options.

(A) The phylum $Echinodermata$ consists of organisms that are exclusively marine.
$Porifera$ (sponges) are mostly marine but some species are found in freshwater.
$Mollusca$ includes both marine and freshwater species.
$Pisces$ (fishes) are found in both marine and freshwater environments.

(B) An open circulatory system is a type of circulatory system where blood is pumped into body cavities,where tissues are surrounded by the blood.
$(i)$ Arthropoda: Most arthropods (e.g.,insects,crustaceans) possess an open circulatory system.
$(ii)$ Mollusca: Most molluscs (except cephalopods like octopus) possess an open circulatory system.
$(iii)$ Annelida: Annelids possess a closed circulatory system.
$(iv)$ Coelenterata: These organisms lack a specialized circulatory system as they rely on diffusion for transport.
Therefore,$(i)$ and $(ii)$ have an open circulatory system.

(C) In $Arthropoda$, the body cavity is a $haemocoel$, which is a blood-filled cavity. The blood flows freely within this cavity, bathing the internal organs directly. This is characteristic of an open circulatory system.

(D) Elephantiasis, also known as filariasis, is a disease characterized by the thickening of the skin and underlying tissues, especially in the legs and male genitals. It is caused by parasitic filarial worms, specifically $Wuchereria \text{ } bancrofti$ and $Wuchereria \text{ } malayi$. These worms are transmitted to humans through the bite of infected mosquitoes. Therefore, the correct option is $D$.

(A) The presence of a notochord is the defining and most striking characteristic of all vertebrates at some stage in their life cycle. While triploblastic condition,gill pouches,and coelom are also found in many non-vertebrate organisms,the notochord is unique to the phylum Chordata,to which all vertebrates belong.

(B) The presence of scales is a characteristic feature of certain vertebrate classes.
$(i)$ Amphibians: Their skin is moist and lacks scales.
$(ii)$ Pisces (Fishes): Most fishes have an exoskeleton of scales.
$(iii)$ Reptiles: Their skin is dry and covered with scales.
$(iv)$ Mammals: Their skin is covered with hair,not scales.
Therefore,both Pisces and Reptiles possess scales. The correct option is $(ii)$ and $(iii)$.

(C) The statement '$C$' is false because not all fishes,amphibians,and reptiles are oviparous.
Some fishes (e.g.,sharks) and some reptiles (e.g.,certain snakes) are viviparous.
Amphibians generally exhibit external fertilization,and while many are oviparous,the classification is not universally applicable to all members of these groups as strictly oviparous.

(D) Pteridophytes are vascular cryptogams,meaning they possess roots,stems,and leaves but do not produce seeds or flowers. Flowers are reproductive structures found exclusively in angiosperms (flowering plants).

(A) $Spongilla$ is a freshwater sponge that belongs to the phylum $Porifera$.
$Euglena$ is a unicellular protist belonging to the kingdom $Protista$.
$Penicillium$ is a type of fungus belonging to the kingdom $Fungi$.
$Hydra$ is a freshwater organism belonging to the phylum $Coelenterata$ (also known as $Cnidaria$).

(B) Filaria is a disease caused by the parasitic worm $Wuchereria$ $bancrofti$. It is not an animal itself,but rather a medical condition. In contrast,$Hydra$,$Corals$,and $Jelly$ $fish$ are all aquatic animals belonging to the phylum $Cnidaria$.

(C) Amphibians possess a three-chambered heart consisting of two atria and one ventricle.
They respire through lungs in their adult stage and through gills during their larval (tadpole) stage.
Their skin is moist and contains mucus glands to prevent desiccation.
Unlike reptiles,amphibians lack scales on their skin,which is why they are often referred to as having 'naked' skin.

(D) Organisms that lack a defined nucleus and membrane-bound cell organelles are classified as prokaryotes.
According to the five-kingdom classification,prokaryotes are placed under the Kingdom Monera.
Cyanobacteria (blue-green algae) and Archaebacteria are both members of the Kingdom Monera.
Fungi and Protista are eukaryotes,meaning they possess a well-defined nucleus and membrane-bound organelles.
Therefore,the correct group is $(iii)$ and $(iv)$.

(A) Classification of living organisms is based on fundamental characteristics such as cellular structure (prokaryotic vs eukaryotic),mode of nutrition (autotrophic vs heterotrophic),and body organization.
Height of a plant is a variable characteristic that changes with age and environmental conditions.
$A$ small shrub and a large tree can both belong to the same group (e.g.,angiosperms).
Therefore,the height of a plant is not a reliable criterion for biological classification.

(B) Protochordates are marine animals that possess a notochord at some stage of their life cycle. They exhibit bilateral symmetry,are triploblastic,and have a coelom. However,jointed legs are a characteristic feature of the phylum $Arthropoda$,which belongs to the kingdom $Animalia$ but is distinct from the phylum $Chordata$ (which includes Protochordata). Therefore,jointed legs are not a feature of Protochordata.

(C) The phylum $Echinodermata$ is characterized by the presence of a water vascular system. The locomotory organs in these organisms are known as $tube feet$ (or $podia$). These structures are used for locomotion, capturing food, and respiration.

(D) Corals belong to the phylum $Cnidaria$ (also known as $Coelenterata$). They are marine invertebrates that typically live in large colonies. These colonies secrete calcium carbonate to form hard,protective skeletons,which eventually build up to form coral reefs.

(A) Carolus Linnaeus introduced the system of scientific nomenclature,specifically known as binomial nomenclature.
This system provides a unique two-part name to every organism,consisting of a genus name and a species name.

(B) two-chambered heart consists of one atrium and one ventricle. This type of heart is characteristic of fish,where deoxygenated blood is pumped to the gills for oxygenation and then distributed to the rest of the body. In contrast,amphibians have a three-chambered heart,while crocodiles and aves (birds) possess a four-chambered heart.

(C) Sharks belong to the class $Chondrichthyes$,which are cartilaginous fish,meaning their endoskeleton is composed entirely of cartilage. In contrast,$Rohu$ and $Tuna$ belong to the class $Osteichthyes$,which are bony fish.

(D) Annelids are characterized by metameric segmentation. $Nereis$,Earthworm,and Leech are members of the phylum Annelida. Sea urchins belong to the phylum Echinodermata,not Annelida.

(A) The book $Systema \text{ } Naturae$ is a seminal work in the history of biological classification. It was written by Carolus Linnaeus, who is known as the father of modern taxonomy. In this book, he introduced the system of binomial nomenclature for naming organisms.

(B) Karl Von Linne,also known as Carolus Linnaeus,is widely recognized as the 'Father of Taxonomy'.
He developed the system of binomial nomenclature,which is the formal system of naming organisms that is still used in biology today.
Therefore,he was primarily involved with the branch of science known as Taxonomy.

(C) Coelenterates exhibit a tissue level of organization,meaning their body is composed of specialized cells organized into tissues but lacks complex organ systems. Therefore,real organs are absent in them.

(D) The members of the phylum $Echinodermata$ (such as starfish and sea urchins) possess an endoskeleton made of calcareous ossicles,which are hard structures composed of calcium carbonate. These structures provide support and protection to the organism.

(A) The phenomenon of metameric segmentation,where the body is divided into repeating segments,is a characteristic feature of the phylum $Annelida$.
Leech $(Hirudinaria)$ belongs to the phylum $Annelida$,and therefore,it exhibits differentiation in a segmental fashion.
Starfish belongs to $Echinodermata$,Snails belong to $Mollusca$,and $Ascaris$ belongs to $Aschelminthes$ (or $Nematoda$),none of which exhibit true metameric segmentation.

(B) The taxonomic hierarchy follows the sequence: Kingdom $\to $ Phylum/Division $\to $ Class $\to $ Order $\to $ Family $\to $ Genus $\to $ Species.
Therefore,the family category is placed between the order and the genus.

(C) The $5$-Kingdom classification system was proposed by $R. H. Whittaker$ in $1969$.
This system classifies organisms into $5$ kingdoms: $Monera$,$Protista$,$Fungi$,$Plantae$,and $Animalia$.
This classification is based on criteria such as cell structure,body organization,mode of nutrition,and phylogenetic relationships.

(A) Blue-green algae (Cyanobacteria) belong to the kingdom $Monera$. Organisms in this kingdom are prokaryotes,which means they lack a membrane-bound,well-defined nucleus and other membrane-bound organelles. In contrast,diatoms,algae,and yeast are eukaryotes and possess a well-defined nucleus.

(B) The book 'On the Origin of Species' was written by Charles Darwin. It was published on $24$ November $1859$ and is considered to be the foundation of evolutionary biology. In this work,Darwin introduced the scientific theory that populations evolve over the course of generations through a process of natural selection.

(C) The presence of jointed legs is a defining characteristic of the phylum $Arthropoda$.
Since insects belong to the class $Insecta$ under the phylum $Arthropoda$,the presence of jointed legs confirms that the animal is an insect.

(A) $T$: $R$.$H$. Whittaker proposed the five-kingdom classification system in $1969$.
$(b)$ $T$: The kingdom Monera is broadly categorized into Archaebacteria and Eubacteria.
$(c)$ $F$: In the taxonomic hierarchy,the order is Class,Order,Family,Genus,Species. Thus,Genus comes before Species.
$(d)$ $T$: Anabaena is a cyanobacterium (blue-green alga),which is a prokaryote and belongs to the kingdom Monera.
$(e)$ $F$: Blue-green algae (cyanobacteria) are prokaryotic organisms and are classified under the kingdom Monera,not Protista.
$(f)$ $T$: All prokaryotic organisms,which lack a defined nucleus and membrane-bound organelles,are placed in the kingdom Monera.

(A-D) Fungi exhibit a saprotrophic mode of nutrition,where they obtain nutrients from decaying organic matter.
$(b)$ The cell wall of fungi is composed of a complex polysaccharide called chitin.
$(c)$ The symbiotic association between blue-green algae (or cyanobacteria) and fungi is known as lichens.
$(d)$ Chemically,chitin is a complex carbohydrate,specifically a nitrogen-containing polysaccharide ($N$-acetylglucosamine).
$(e)$ Species is the basic unit of classification and contains the smallest number of organisms with the maximum number of similar characters.
$(f)$ Plants that lack a well-differentiated body structure (stem,root,and leaf) are classified under the group Thallophyta.
$(g)$ Bryophytes are referred to as the amphibians of the plant kingdom because they require water for fertilization despite living on land.

(N/A) The classification of the given seeds is as follows:
$1$. Gram: Dicot (contains two cotyledons).
$2$. Wheat: Monocot (contains one cotyledon).
$3$. Rice: Monocot (contains one cotyledon).
$4$. Pumpkin: Dicot (contains two cotyledons).
$5$. Maize: Monocot (contains one cotyledon).
$6$. Pea: Dicot (contains two cotyledons).

(A) The correct matches are as follows:
$(a)$ Naked seed: $(B)$ Gymnosperms (seeds are not enclosed in fruits).
$(b)$ Covered seed: $(A)$ Angiosperms (seeds are enclosed within fruits).
$(c)$ Flagella: $(D)$ Euglena (locomotory organelle).
$(d)$ Marchantia: $(C)$ Bryophytes (a type of liverwort).
$(e)$ Marsilea: $(F)$ Pteridophyta (a type of fern).
$(f)$ Cladophora: $(E)$ Thallophyta (a type of green algae).
$(g)$ Penicillium: $(G)$ Fungi (a type of fungus).
Therefore, the correct sequence is $(a) - B, (b) - A, (c) - D, (d) - C, (e) - F, (f) - E, (g) - G$.

(B) Pore bearing animals are classified under the phylum Porifera $(C)$.
$(b)$ Diploblastic animals (having two germ layers) are characteristic of the phylum Coelenterata $(B)$.
$(c)$ Metameric segmentation is a key feature of the phylum Annelida $(F)$.
$(d)$ Jointed legs are the defining characteristic of the phylum Arthropoda $(A)$.
$(e)$ Soft-bodied animals are characteristic of the phylum Mollusca $(E)$.
$(f)$ Spiny-skinned animals belong to the phylum Echinodermata $(D)$.
Therefore, the correct matching is $(a) - C, (b) - B, (c) - F, (d) - A, (e) - E, (f) - D$.

(N/A) $Spongilla$ - Acoelomate
$Sea \text{ } anemone$ - Acoelomate
$Planaria$ - Acoelomate
$Liver \text{ } fluke$ - Acoelomate
$Wuchereria$ - Pseudocoelomate
$Ascaris$ - Pseudocoelomate
$Nereis$ - Coelomate
$Earthworm$ - Coelomate
$Scorpion$ - Coelomate
$Birds$, $Fishes$, and $Horse$ - Coelomate

(N/A) The classification of the given fishes based on their endoskeleton is as follows:
$1$. $Torpedo$ (Electric ray): Cartilaginous fish (Chondrichthyes).
$2$. $Sting$ $ray$: Cartilaginous fish (Chondrichthyes).
$3$. $Dog$ $fish$ $(Scoliodon)$: Cartilaginous fish (Chondrichthyes).
$4$. $Rohu$ ($Labeo$ $rohita$): Bony fish (Osteichthyes).
$5$. $Angler$ $fish$: Bony fish (Osteichthyes).
$6$. $Exocoetus$ (Flying fish): Bony fish (Osteichthyes).

(N/A) The classification based on the number of heart chambers is as follows:
$1$. $2$-chambered heart: Rohu,Scoliodon.
$2$. $3$-chambered heart: Frog,Salamander,Flying lizard,King Cobra.
$3$. $4$-chambered heart: Crocodile,Ostrich,Pigeon,Bat,Whale.

(N/A) Animals are classified based on their ability to regulate body temperature:
$1$. Cold-blooded (Poikilothermic) animals: These animals cannot maintain a constant body temperature and their body temperature changes with the environment. These include: Rohu (Fish),Scoliodon (Dogfish),Frog (Amphibian),Salamander (Amphibian),Flying lizard (Reptile),King Cobra (Reptile),and Crocodile (Reptile).
$2$. Warm-blooded (Homeothermic) animals: These animals maintain a constant body temperature regardless of the environment. These include: Ostrich (Bird),Pigeon (Bird),Bat (Mammal),and Whale (Mammal).

(N/A) The two egg-laying mammals,also known as monotremes,are:
$(i)$ Platypus (Ornithorhynchus anatinus)
$(ii)$ Echidna (Tachyglossidae family,also known as spiny anteaters)

(N/A) Robert Whittaker
$(b)$ Species
$(c)$ Monera
$(d)$ Eukaryotic unicellular nature
$(e)$ Chlorophyll
$(f)$ Mushroom
$(g)$ Yeast
$(h)$ Lichens

(A) $F$: Gymnosperms have naked seeds,whereas Angiosperms have covered seeds.
$(b)$ $T$: Cryptogamae are plants that do not produce flowers or seeds.
$(c)$ $F$: Bryophytes lack specialized conducting tissues like xylem and phloem.
$(d)$ $T$: Funaria is a common genus of mosses.
$(e)$ $T$: Many ferns possess fronds which are compound leaves.
$(f)$ $T$: $A$ seed is a reproductive structure that contains an embryo,food supply,and a protective coat.

(A) Liver fluke (Fasciola hepatica) exhibits bilateral,dorsiventral symmetry.
$(b)$ Wuchereria bancrofti (Filarial worm) is the causative agent of elephantiasis.
$(c)$ Arthropods possess an open circulatory system where the coelomic cavity,known as the haemocoel,is filled with blood.
$(d)$ Nematodes (Roundworms) are characterized by the presence of a pseudocoelom,a body cavity that is not completely lined by mesoderm.

(N/A) Dorsal fin
$(b)$ Caudal fin
$(c)$ Pelvic fin
$(d)$ Pectoral fin
Function of Caudal fin: The Caudal fin (tail fin) acts as a rudder and helps the fish in steering,balancing,and providing propulsion for streamlined movement in water.

(N/A) Thallophyta
$(b)$ Without specialized vascular tissue
$(c)$ Pteridophyta
$(d)$ Phanerogams
$(e)$ Bear naked seeds
$(f)$ Angiosperms
$(g)$ Have seeds with two cotyledons
$(h)$ Monocots

(N/A) Examples of thallophytes include: Ulothrix,Spirogyra,Cladophora,Ulva,and Chara.
The labelled diagram of Spirogyra shows the following structures:
$1$. Cell wall: The outer protective layer.
$2$. Chloroplast: The ribbon-shaped,spiral structure involved in photosynthesis.
$3$. Pyrenoids: Small bodies found within the chloroplast that store starch.
$4$. Nucleus: The central control unit of the cell.
$5$. Cytoplasm: The jelly-like substance filling the cell.