Mix Example - DIVERSITY IN LIVING ORGANISMS Questions in English

(N/A) Thallophyta,Bryophyta,and Pteridophyta are classified as 'Cryptogams' because their reproductive organs are inconspicuous or hidden,and they do not produce seeds.
On the other hand,'Phanerogams' include Gymnosperms and Angiosperms. These plants possess well-differentiated reproductive tissues and produce seeds. In these plants,the embryo develops into a seed,which contains stored food for future growth.
An example of a Gymnosperm is $Pinus$ (Pine),which is a coniferous tree that produces seeds in cones.

(N/A) Bilateral symmetry: It is a body plan in which the left and right halves of the body are mirror images of each other,e.g.,Liver fluke.
$(b)$ Coelom: It is the internal body cavity between the visceral organs and the body wall in which well-developed organs can be accommodated,e.g.,Butterfly.
$(c)$ Triploblastic: Animals having three germinal layers (ectoderm,mesoderm,and endoderm) from which differentiated tissues and organs can be formed are called triploblastic,e.g.,Starfish.

(N/A) No,all these organisms do not belong to the same group.
$1$. Leech and Nereis belong to the phylum $Annelida$ because they exhibit metameric segmentation,meaning their body is divided into many segments internally by septa.
$2$. Scolopendra,prawn,and scorpion belong to the phylum $Arthropoda$ because they possess jointed appendages,a chitinous exoskeleton,and an open circulatory system.

(C) The $Mango$ $tree$ is the most complex and evolved organism among the three.
$1$. $Mango$ $tree$ ($Mangifera$ $indica$) is a multicellular,eukaryotic,autotrophic plant with a well-developed vascular system,complex tissue organization,and seeds enclosed within fruits (Angiosperm).
$2$. $Bacteria$ are unicellular,prokaryotic organisms with a very simple cellular structure and lack membrane-bound organelles.
$3$. $Mushrooms$ (Fungi) are heterotrophic,eukaryotic organisms,but they lack complex tissue systems and vascular tissues,and they do not produce seeds or fruits.

(N/A) The differences between a flying lizard $(Draco)$ and a bird are as follows:
$1$. Classification: Flying lizard belongs to the class $Reptilia$,while birds belong to the class $Aves$.
$2$. Body Temperature: Flying lizards are cold-blooded (poikilothermic),whereas birds are warm-blooded (homeothermic).
$3$. Body Covering: The body of a flying lizard is covered with scales,while the body of a bird is covered with feathers.
$4$. Heart Structure: Flying lizards typically have a three-chambered heart,whereas birds have a four-chambered heart.
$5$. Locomotion: Flying lizards use skin folds (patagium) for gliding,while birds have forelimbs modified into wings for true flight.

(N/A) Bat,rat,and cat belong to the class $Mammalia$ and share the following common features:
$(a)$ All possess a notochord at some stage of their life cycle.
$(b)$ All are warm-blooded (homeothermic) animals.
$(c)$ All have a four-chambered heart.
$(d)$ All have skin covered with hair and possess sweat and oil glands.

(C) Snakes and turtles are both classified under the class $Reptilia$ because they share several key characteristics:
$(1)$ They are cold-blooded (poikilothermic) animals.
$(2)$ Their skin is dry and covered with scales or scutes.
$(3)$ They breathe exclusively through lungs.
$(4)$ They typically possess a three-chambered heart (except for crocodiles).
$(5)$ They are oviparous,meaning they lay eggs with a tough,leathery,or calcareous covering on land.

(N/A) According to Charles Darwin, evolution is the process by which life forms arise through the accumulation of changes in body design over generations, which help the organisms possessing these changes to survive and adapt better to their environment.

(B) Gymnosperms are known as 'naked-seeded' plants because their seeds are not enclosed within an ovary or fruit.
Instead,the seeds of gymnosperms typically develop on the surface of specialized reproductive structures known as scales or leaves,often organized into cones (strobili).

(B) The five-kingdom system of classification was proposed by $R.H.$ Whittaker in $1969$.
He classified organisms into five kingdoms: $Monera$,$Protista$,$Fungi$,$Plantae$,and $Animalia$.
This classification is based on cell structure,body organization,mode of nutrition,and phylogenetic relationships.

(B) Symbiosis is defined as an obligatory mutually beneficial association between two different organisms living in close physical contact. In this relationship,both organisms derive benefits from each other,which is essential for their survival.

(A) The body cavity in certain invertebrates,such as arthropods and molluscs,which is filled with haemolymph (blood) is known as haemocoel.
In these organisms,the circulatory system is open,meaning blood does not remain confined within blood vessels but flows into these open spaces to bathe the tissues directly.

(B) The haemocoel is a body cavity filled with blood,which is a characteristic feature of the phyla Arthropoda and Mollusca. In these animals,the circulatory system is open,meaning blood flows through the body cavity (haemocoel) rather than being confined entirely within blood vessels.

(A) The heart of fishes consists of $2$ chambers,which include one atrium and one ventricle.
In contrast,the heart of frogs consists of $3$ chambers,which include two atria and one ventricle.

(B) The two-kingdom classification system was proposed by $Carolus \ Linnaeus$ in $1758$. He divided all living organisms into two kingdoms: $Plantae$ and $Animalia$.

(N/A) Liver fluke (Fasciola hepatica) and Planaria belong to the phylum Platyhelminthes. These organisms are commonly known as flatworms because their bodies are dorsoventrally flattened.

(B) Leech (Hirudinaria) and Earthworm (Pheretima) belong to the phylum $Annelida$.
These organisms are characterized by a segmented body,which is a key feature of the phylum $Annelida$.

(B) Lichens are symbiotic associations between fungi and algae. They are highly sensitive to air pollution,particularly sulfur dioxide $(SO_{2})$,and are therefore used as bioindicators of air quality.

(N/A) Echinoderms possess a unique water-driven system known as the $Water$ $Vascular$ $System$,which is primarily used for locomotion,capturing food,and respiration.
Their endoskeleton is composed of hard,calcareous structures made of $Calcium$ $Carbonate$ $(CaCO_3)$ plates or ossicles.

(N/A) The term $diploblastic$ refers to organisms whose body cells are arranged in two embryonic layers: an external $ectoderm$ and an internal $endoderm$.
Between these two layers,an undifferentiated layer called $mesoglea$ is present.
Example: $Hydra$ (belonging to the phylum $Cnidaria$).

(B) In binomial nomenclature,the first word represents the genus and the second word represents the species.
Therefore,in the scientific name $Homo$ $sapiens$,$Homo$ is the generic name (genus) and $sapiens$ is the specific epithet (species).

(N/A) The importance of classification is as follows:
$(a)$ It facilitates the identification of organisms.
$(b)$ It helps to establish the relationships among various groups of organisms.
$(c)$ It helps to study the phylogeny and evolutionary history of organisms.
$(d)$ By studying a few representative organisms,the characteristics of the entire group can be understood.

(N/A) Diploblastic animals are those whose body is made up of two germinal layers (ectoderm and endoderm),whereas triploblastic animals have three germinal layers (ectoderm,mesoderm,and endoderm).
$(b)$ Warm-blooded animals (homeotherms) can maintain a constant internal body temperature regardless of the external environment,whereas cold-blooded animals (poikilotherms) change their body temperature according to the fluctuations in the environmental temperature.

(B) Bilateral symmetry is a type of body organization where the body of an organism can be divided into two identical left and right mirror-image halves by only one single plane passing through the central axis.
This is a characteristic feature of most complex animals,including humans,insects,and fish.

(N/A) notochord is a long,rod-like support structure (the term 'chord' means string) that runs along the back of an animal's body.
It serves to separate the nervous tissue from the gut.
Its primary function is to provide a site for muscle attachment,which facilitates ease of movement for the organism.

(N/A) They are unicellular and primarily aquatic organisms.
$(b)$ They possess a typical eukaryotic cell structure with membrane-bound organelles and a well-defined nucleus.
$(c)$ Locomotion is facilitated by structures such as cilia,flagella,or pseudopodia.
$(d)$ Reproduction occurs through both asexual (e.g.,binary fission) and sexual (e.g.,syngamy) methods.

(N/A) The group is Kingdom Protista. These are unicellular eukaryotic organisms that can perform photosynthesis. Example: $Euglena$.
$(b)$ The group is Phylum Annelida. These organisms have a segmented body (metamerism) and can be either unisexual or hermaphrodite. Example: $Earthworm$ $(Pheretima)$.

(B) Bryophytes are referred to as the amphibians of the plant kingdom because,although they are terrestrial plants that live in damp and shaded areas,they require water for the process of fertilization. The male gametes (antherozoids) must swim through a film of water to reach the female gamete (egg) in the archegonium,making water essential for their life cycle.

(N/A) $X$ represents the tentacles,which are used for capturing prey and locomotion.
$Y$ represents the basal disc (or foot),which is used for attachment to a substrate.

(N/A) $A -$ Mouth
$B -$ Dorsal fin
$C -$ Pectoral fin
$D -$ Brood pouch (This is where the male carries the eggs until they hatch.)

(N/A) Gymnosperms are a group of plants that bear naked seeds,meaning the seeds are not enclosed within a fruit.
Characteristic features:
$(i)$ They are usually perennial plants.
$(ii)$ They are typically evergreen and woody plants.

(N/A) Characteristic features of nematodes:
$(i)$ Nematodes have a cylindrical,bilaterally symmetrical,and triploblastic body.
$(ii)$ They are often parasitic and can cause diseases in plants and animals.
$(b)$ $(i)$ The phylum is $Echinodermata$. These organisms possess a spiny skin (calcareous ossicles),radial symmetry in adults,and a water vascular system with tube feet for locomotion.
$(ii)$ The phylum is $Annelida$. These organisms are triploblastic,coelomate,and exhibit true segmentation (metamerism) in their worm-like bodies.

(D) Bats are not classified as birds because:
$(i)$ They lack feathers,which are a characteristic feature of birds.
$(ii)$ They possess mammary glands,which is a defining characteristic of mammals.
$(iii)$ They give birth to live young ones rather than laying eggs.
$(iv)$ Their body is covered with hair instead of feathers.

(N/A) Crocodile: Most reptiles have a three-chambered heart,but the crocodile is an exception with a four-chambered heart.
$(b)$ Platypus: Also known as the duck-billed platypus,it is a monotreme that lays eggs instead of giving birth to live young.
$(c)$ Tapeworm: These are flatworms that live as parasites in the intestines of other animals.
$(d)$ Thallophyta: This division includes plants like algae that have a simple,undifferentiated body structure (thallus).

(A) Arthropoda: These organisms possess jointed appendages,which is a characteristic feature of this phylum.
$(b)$ Platyhelminthes: These organisms are commonly known as flatworms due to their dorso-ventrally flattened bodies.
$(c)$ Annelida: These organisms exhibit true segmentation or metamerism in their body structure.
$(d)$ Echinodermata: These organisms have a spiny-skinned body surface,which is a diagnostic feature of this phylum.

(N/A) Lizards: They possess two pairs of pentadactyl limbs.
Snakes: Pentadactyl limbs are absent.
$(b)$ Fungi exhibit a saprophytic mode of nutrition,where they absorb nutrients from dead and decaying organic matter.

(N/A) Saprophytes are organisms that obtain their nutrition from dead and decaying organic matter.
$(b)$ They belong to the Kingdom $Fungi$.
$(c)$ The cell wall of fungi is composed of a complex sugar called $chitin$.

(B) The classification is based on the nature of reproductive organs:
$1$. Thallophytes,Bryophytes,and Pteridophytes are classified as Cryptogamae (from Greek 'kryptos' meaning hidden and 'gamos' meaning marriage) because they have inconspicuous or hidden reproductive organs and do not produce seeds.
$2$. Gymnosperms and Angiosperms are classified as Phanerogamae (from Greek 'phaneros' meaning visible) because they have well-differentiated,visible reproductive organs and produce seeds.

(N/A) Binomial nomenclature is a formal system of naming living organisms by giving them a two-part name consisting of a generic name (genus) and a specific epithet (species).
Advantages:
$(i)$ It provides a standardized and unique name for each organism,which helps in the systematic study of the wide range of living organisms across the globe.
$(ii)$ It helps in maintaining an accurate record of biodiversity,which is essential for the identification and classification of organisms.

(N/A) Similarities: Both fungi and plants possess a rigid cell wall,which provides structural support to the organism.
Dissimilarities: Fungi are heterotrophic,meaning they obtain nutrients by absorbing organic matter from their environment,often acting as saprophytes or parasites. In contrast,plants are autotrophic,containing chlorophyll,which allows them to synthesize their own food through the process of photosynthesis.

(N/A) The given figure shows a plant with reticulate venation in its leaves,which is a characteristic feature of a dicot plant.

Feature	Dicot Plant	Monocot Plant
Venation in leaf	Reticulate venation	Parallel venation
Number of cotyledons	Two cotyledons	One cotyledon

(N/A) Saprophytes use decaying organic material as their source of food.
Many saprophytes have the capacity to become multicellular organisms at certain stages in their lives.
They possess cell walls made of a tough,complex sugar called chitin.
Some species exhibit symbiotic behavior.

(N/A) The phylum to which Ascaris belongs is Nematoda (or Aschelminthes).
Two characteristic features of this phylum are:
$1$. The body is cylindrical in shape and circular in cross-section.
$2$. They are pseudocoelomate,meaning they possess a false body cavity.
The parasitic worm that causes elephantiasis (filariasis) is Wuchereria bancrofti (commonly known as the Filarial worm).

(N/A) Platyhelminthes are acoelomate,meaning they lack a true body cavity (coelom).
They exhibit both lifestyles: many species are parasitic (e.g.,Tapeworms,Liver flukes),while some are free-living (e.g.,Planaria).

(A) Porifera: These are multicellular organisms without true tissues and possess numerous pores (ostia) on their body.
$(b)$ Pteridophyta: These plants have a well-differentiated body into roots,stems,and leaves but are cryptogams,meaning they do not produce seeds.
$(c)$ Platyhelminthes: These are commonly known as flatworms,characterized by a dorsoventrally flattened body and the absence of a coelom (acoelomate).
$(d)$ Annelida: These are segmented worms that possess a true coelom (body cavity) and show a high degree of organ differentiation.

(N/A) The animal belongs to the phylum $Platyhelminthes$.
They are commonly called 'flatworms' because of their dorsoventrally flattened bodies.
One example is $Planaria$ (or $Fasciola$ / Liver fluke,or $Taenia$ / Tapeworm).

(N/A)

Similarities between nematodes and annelids	Differences between nematodes and annelids
$1.$ Both have a bilaterally symmetrical body.	$1.$ Annelids have a segmented body,whereas nematodes have a cylindrical body.
$2.$ Both have triploblastic germ layers.	$2.$ Annelids have a true body cavity (coelom),whereas nematodes have a pseudocoelom.

(N/A) $(i)$ Chitin is a complex polysaccharide,specifically a nitrogen-containing derivative of glucose known as $N$-acetylglucosamine.
$(ii)$ Fungi exhibit a saprophytic mode of nutrition,where they absorb dissolved organic nutrients from dead and decaying matter by secreting digestive enzymes.

(N/A) Based on the structure for locomotion:
$(i)$ Organisms having pseudopodia,e.g.,$Amoeba$.
$(ii)$ Organisms having hair-like cilia,e.g.,$Paramecium$.
$(iii)$ Organisms having whip-like flagella,e.g.,$Euglena$.
$(b)$ Based on the mode of nutrition:
$(i)$ Autotrophic: $Chlamydomonas$.
$(ii)$ Heterotrophic: $Oomycetes$ (or $Amoeba$ as a holozoic heterotroph).

(N/A) Label $A$ represents Resting spores (Akinetes).
Label $B$ represents Heterocyst.
$(b)$ The organism shown is $Anabaena$ and it belongs to the kingdom $Monera$.
$(c)$ Two other organisms belonging to the kingdom $Monera$ are $Bacteria$ and $Mycoplasma$.