Chapter 10 Biodiversity And Its Classification Review Questions Environment Review Questions MCQs
Question 1. Five kingdom classification was introduced by
- Darwin
- Hutchinson
- Lamarck
- Whitaker
Answer: 4. Whitaker
Question 2. The bacteria that can utilize methane usually belong to
- Archea
- Mycoplasma
- Eubacteria
- Actinomycetes
Answer: 1. Archea
Read And Learn More: WBBSE Solutions For Class 6 School Science
Question 3. The following group of organisms is without flagella
- Eubacteria
- Protozoa
- Fungi
- Cyanobacteria
Answer: 4. Cyanobacteria
Question 4. The free-living nitrogen-fixing bacterial include
- Rhizobium
- Nostoc
- Clostridium
- Frankia
Answer: 3. Clostridium
Question 5. The organism that is in between virus and monera is
- Chlamydia
- Mycoplasma
- Actinomycetes
- Fungi
Answer: 1. Chlamydia
Question 6. The group having unicellular eukaryotes is
- Monera
- Protista
- Fungi
- Plantae
Answer: 2. Protista
Question 7. The group that is intermediate between
- Mycoplasma
- Cyanobacteria
- Chlamydia
- Actinomycetes
Answer: 4. Actinomycetes
Question 8. The diatoms have the following character
- Valves
- Silica wall
- Both
- Cilia
Answer: 3. Both
Question 9. Red tide is caused by
- Diatoms
- Dinoflagellates
- Protozoa
- Red algae
Answer: 2. Dinoflagellates
WBBSE Class 6 Biodiversity MCQs
Question 10. Yeast belongs to
- Zygomycetes
- Oomycetes
- Ascomycetes
- Basidiomycetes.
Answer: 3. Ascomycetes
Question 11. Sexual reproduction is not found in
- Ascomycetes
- Oomycetes
- Basidiomycetes
- Deuteromycetes
Answer: 4. Deuteromycetes
Question 12. The amphibious plant is
- Algae
- Bryophyte
- Pteridophyte
- Gymnosperm
Answer: 2. Bryophyte
Question 13. The most developed gymnosperm is
- Cycas
- Pinus
- Ginkgo
- Gnetum
Answer: 4. Gnetum
Question 14. The naked-seeded plant is
- Pinus
- Riccia
- Ferns
- Chinarose
Answer: 1. Pinus
Question 15. The algae with xanthophyll belong to
- Green algae
- Yellow-green algae
- Brown algae
- Red algae
Answer: 2. Yellow-green algae
Common MCQs on Ecosystem Diversity
Question 16. The plant which belongs to vascular cryptogam is
- Algae
- Mosses
- Ferns
- Gymnosperm
Answer: 3. Ferns
Question 17. The animal with a flat body is
- Flatworms
- Roundworms
- Annelida
- Mollusca
Answer: 1. Flatworms
Question 18. The animal with a water vascular system is
- Snail
- Starfish
- Cockroach
- Earthworm
Answer: 2. Starfish
Question 19. The shark is
- Bony fish
- Cartilaginous fish
- Lungfish
- Amphibia
Answer: 2. Cartilaginous fish
Question 20. Platypus is a
- Hemichordate
- Cephalochordate
- Urochordate
- Vertebrate
Answer: 4. Vertebrate
Question 21. ‘Water Silk’ belongs to
- Bryophyta
- Algae
- Pteridophyta
- Fungi
Answer: 2. Algae
Question 22. Which among the following does not possess the notochord?
- Vertebrata
- Cephalochordata
- Urochordata
- Hemichordata
Answer: 4. Hemichordata
Question 23. The vertebrate which is terrestrial throughout life, which lays eggs on land and moves around with the help of abdominal scales is
- Pisces
- Amphibians
- Reptiles
- Birds
Answer: 3. Reptiles
Chapter 10 Biodiversity And Its Classification Fill in the Blanks
Question 1. The bacteria belongs to ___________.
Answer: Monera
Question 2. Methanogen belongs to ___________.
Answer: Archea
Question 3. The cyanobacteria are ___________ in color.
Answer: Blue-green
Question 4. Yeast belongs to ___________.
Answer: Ascomycetes
Question 5. Amphioxus belongs to ___________.
Answer: Cephalochordata
Question 6. Balanoglossus belongs to ___________.
Answer: Hemichordata
Question 7. ___________ are amphibious plants.
Answer: Bryophytes
Question 8. ___________ root is present in Cycas.
Answer: Corallid
Question 9. Chondricthyes belong to ___________ fish.
Answer: Cartilaginous
Question 10. The frog has fish ___________ chambered heart.
Answer: Three
Question 11. The unicellular animal is ___________.
Answer: Protozoa
Question 12. The largest animal group is ___________.
Answer: Arthropoda
Question 13. The flowering plants are called ___________
Answer: ASngiosperms
Question 14. The external pinna is a character of ___________
Answer: Mammals
Question 15. The reproductive structure of the fern is called ___________
Answer: Sorus
Question 16. The fungus without sexual reproduction is ___________.
Answer: Deuteroycetes
Question 17. The locomotory organ of algae is ___________.
Answer: Flagella
Question 18. The oomycetes produce the reproductive spore called ___________.
Answer: Oospore
Question 19. Retrogressive evolution is observed in ___________.
Answer: Urochordata
Question 20. Red tide is brought about by ___________.
Answer: Dinoflagellates
Chapter 10 Biodiversity And Its Classification Identify As True Or False
Question 1. Archebacteria can survive in extreme environmental conditions.
Answer: True
Question 2. Bacteria belong to the kingdom Protista.
Answer: False
Question 3. Mycoplasma is devoid of cell walls.
Answer: True
Question 4. The diatom cell wall is made of calcium.
Answer: False
Question 5. Riccia is a leafy bryophyte.
Answer: False
Question 6. Pteridophytes are vascular cryptogams.
Answer: True
Question 7. Gnetum is the most advanced gymnosperm.
Answer: True
Question 8. Angiosperms are subdivided into 3 major groups.
Answer: False
Question 9. Protozoa belong to the group of Protista.
Answer: True
Question 10. Fungi are non-chlorophyllous organisms.
Answer: True
Question 11. Zygospore is observed in Oomycetes.
Answer: False
Question 12. Hydra belongs to Ctenophora.
Answer: False
Question 13. Frogs belong to a group of amphibious organisms.
Answer: True
Question 14. Earthworm exhibits open circulation.
Answer: False
Question 15. Cephalochordata has notochord extended up to the head region.
Answer: True
Question 16. Insects belong to the group Arthropoda.
Answer: True
Question 17. Sponges do not have any structural organization.
Answer: True
Question 18. Tapeworms are bisexual animals.
Answer: True
Question 19. Hair is a characteristic feature of Amphibia.
Answer: False
Question 20. Mammals have external ears.
Answer: True
Chapter 10 Biodiversity And Its Classification Match The Columns
Question 1.
Answer: A-D, B-C, C-E, D-A
Question 2.
Answer: A-D, B-A, C-E, D-B
Question .3.
Answer: A-D, B-C, C-B, D-A
Question 4.
Answer: A-E, B-A, C-B, D-D
Question 5.
Answer: A-C, B-D, C-E, D-A
Chapter 10 Biodiversity And Its Classification Answer In Words Or A Sentence
Question 1. Name the component of the cell wall of bacteria.
Answer: Peptidoglycan.
Question 2. What is the color of cyanobacteria?
Answer: Blue-green.
Question 3. What is meant by PPLO?
Answer: Pleuro Pneumonia Like Organisms.
Question 4. What are the five major kingdoms?
Answer: Monera, Protista, fungi, Plantae, Animalia.
Question 5. What are the different types of diatoms?
Answer: Centric and Pinnate.
Question 6. What are the different types of bryophytes?
Answer: Hepaticae, anthracene, moss.
Question 7. Why bryophytes are called amphibious plants?
Answer: The bryophytes are called amphibious plants because they grow on land but reproduce with the help of water.
Question 8. Why pteridophytes are called vascular cryptogams?
Answer: They are lower plants with true xylem and phloem.
Question 9. Why is Gnetum advanced?
Answer: They have true xylem vessels and perianth.
Question 10. What are the two layers of tissue in Hydra?
Answer: Ectoderm and Endoderm.
Question 11. How can you identify monocot and dicot plants by their leaves?
Answer: Leaves of monocot plants have parallel venation while those of dicot plants have reticulate venation.
Question 12. Why are arthropods so-called?
Answer: They have jointed appendages.
Question 13. Why is Chordata so-called?
Answer: They are so-called because of the presence of notochord.
Question 14. Name the group under invertebrate chordate.
Answer: Urochordata and Cephalochordata.
Question 15. Write one difference between Gymnosperms and Angiosperms.
Answer: Gymnosperms do not bear fruits and the seeds remain exposed. Angiosperms bear fruits inside which seeds remain enclosed.
Chapter 10 Biodiversity And Its Classification Short Answer Type Questions
Question 1. Why are prokaryotes so-called?
Answer: The prokaryotes are without true nuclear membranes.
Question 2. What are the two types of bacteria?
Answer: The bacteria that retain Gram stain are called Gram-positive and the one which does not retain Gram stain are called Gram-negative.
Question 3. What are the major pigments present in cyanobacteria?
Answer: The blue-green c-phycocyanin, red-colored c-phycoerythrin, and chlorophyll-a.
Question 4. Why is Protista a mixed group?
Answer: The protista is a mixed group because it has all the unicellular eukaryotes including plant, animal, and fungal members.
Question 5. Why are myxomycetes close to protozoa?
Answer: These organisms have pseudopodia or false feet.
Understanding Biodiversity and Its Classification
Question 6. What is a zygospore?
Answer: Zygospore is a thick-walled spore produced by the union of 2 gametangia, which act as resting spores and germinate to produce new plant bodies.
Question 7. What is meant by basidiospore?
Answer: It is the sexual reproductive spore found in basidiomycetes fungi. It is borne on an oval structure called basidia, on finger-like projections called sterigmata.
Question 8. What is Hepaticae?
Answer: It is a thalloid structure with an apical notch, growing in a round tier-like configuration, the individual thallus looks like a liver and that is why the name Hepaticae is given, for example, Riccia.
Question 9. What is meant by ferns?
Answer: They represent the advanced group of pteridophytes, having compound leaves, soft rhizomatous stems, and root-like rhizoids. The reproductive structure is borne on the ventral surface of the leaves and they are called sorus.
Question 10. What are coralloid roots?
Answer: The root of Cycas gets coiled after getting infected with cyanobacteria or blue-green algae, it helps in better absorption of nutrients.
Question 11. How male and female cones of Pinus can be identified?
Answer: The male cones are borne in the upper branches, they are small non-woody, and borne in clusters, while the female cones are borne in the lower branches, they are large, woody, 2- 3 arising from each branch.
Short Answers on Biodiversity Concepts
Question 12. What is the reproductive structure of Angiosperms?
Answer: The reproductive structure of the angiosperm is called a flower. It consists of 4 whorls, 2 accessory whorls in the form of calyx and corolla, and 2 essential whorls, the male androecium and female gynoecium.
Question 13. What is metagenesis?
Answer: Metagenesis is the unique alternation of generation observed in cnidaria; the asexual reproductive stage is called a polyp, while the sexual reproductive stage is called medusae.
Question 14. Why tapeworms are an ideal parasite?
Answer: The tapeworms have a dorsoventrally flattened body, they have hooks and suckers for attachment, they absorb all along their body, they can regenerate their body, and they have multiple larval stages.
Question 15. What is the venous heart?
Answer: The heart of fish is a 2-chambered heart, so deoxygenated venous blood always flows through it, hence it is called a venous heart.
Question 16. How birds are adapted to fly?
Answer: The birds have a boat-shaped body, the anterior pair of limbs is modified to produce wings supported by long feathers, and the bones are made light because of the presence of air spaces within.
Question 17. How many cotyledons are present in the following plants
Answer: Betel nut, Pea, Cardamom, Pumpkin
Hence identify them as monocotyledonous or
dicotyledonous.
Monocotyledonous (seeds containing one cotyledon): Betel nut, Cardamom Dicotyledonous (seeds containing two cotyledons): Pea, Pumpkin
Question 18. List out two features that are not found in starfish but are present in rohu fish.
Answer:
Two features:
1. Presence of vertebral column.
2. Presence of bony endoskeleton.
Question 19. List out two major differences between vertebrates and invertebrates.
Answer:
Question 20. List two major differences between algae and fungi.
Answer:
Chapter 10 Biodiversity And Its Classification Long Answer Type Questions
Question 1. What are the major characteristics of cyanobacteria?
Answer:
Archebacteria:
- They are the oldest organisms in this world.
- They survive in extreme environmental conditions.
- They are anaerobic and are the ancestor of present-day organisms, for example, Methanogenic bacteria.
Eubacteria:
- These bacteria represent the largest group of prokaryotic organisms.
- They are classified on the basis of cell wall structure example Gram positive and Gram negative in nature.
- They are both aerobic and anaerobic in nature and can also be classified on the basis of nutrition, the presence or absence of flagella, for example, Mycobacterium, and Vibrio.
Cyanobacteria:
- They are blue-green in color due to the stun presence of unique pigments called chlorophyll-a and c-phycocyanin.
- They are without flagella, grow in water, and do not have true sexual reproduction.
- They have nitrogen-fixing ability and may be used as biofertilizers, for example Nostoc, and Anabaena.
Mycoplasma :
1. They are bacteria-like organisms without any cell wall and so they are capable of slime changing their shape, also called Pleuronsdm Pneumonia Like Organisms (PPLO), for example, Mycoplasma.
Important Definitions Related to Biodiversity
Chlamydia:
- This organism is an intermediate between viruses and living organisms.
- It does not have true cells and causes parrot fever, for example, Chlamydia.
Actinomycetes:
- They are intermediate between fungi and bacteria.
- They are filamentous in nature and cut off thin-walled spores in chains.
- They are mostly soil-borne, and produce yes, antibiotics, for example, Streptomyces.
Question 2. What are the structural peculiarities of PPLO?
Answer:
Monera
- The unicellular prokaryotic organisms. which do not have true nuclei bound by a nuclear membrane.
- These organisms are the oldest organisms in this world.
- They can survive in extreme environmental conditions. Monera includes the following organisms.
Archebacteria:
- They are the oldest organisms in this world.
- They survive in extreme environmental conditions.
- They are anaerobic and are the ancestor of present-day organisms, for example, Methanogenic bacteria.
Eubacteria:
- These bacteria represent the largest group of prokaryotic organisms.
- They are classified on the basis of cell wall structure example Gram positive and Gram negative in nature.
- They are both aerobic and anaerobic in nature and can also be classified on the basis of nutrition, the presence or absence of flagella, for example, Mycobacterium, and Vibrio.
Cyanobacteria:
- They are blue-green in color due to the stun presence of unique pigments called chlorophyll-a and c-phycocyanin.
- They are without flagella, grow in water, and do not have true sexual reproduction.
- They have nitrogen-fixing ability and may be used as biofertilizers, for example Nostoc, and Anabaena.
Mycoplasma :
1. They are bacteria-like organisms without any cell wall and so they are capable of slime changing their shape, also called Pleuronsdm Pneumonia Like Organisms (PPLO), for example, Mycoplasma.
Chlamydia:
- This organism is an intermediate between viruses and living organisms.
- It does not have true cells and causes parrot fever, for example, Chlamydia.
Actinomycetes:
- They are intermediate between fungi and bacteria.
- They are filamentous in nature and cut off thin-walled spores in chains.
- They are mostly soil-borne, and produce yes, antibiotics, for example, Streptomyces.
Question 3. What is the intermediate between bacteria and fungi? State its structural features.
Answer:
Monera
- The unicellular prokaryotic organisms. which do not have true nuclei bound by a nuclear membrane.
- These organisms are the oldest organisms in this world.
- They can survive in extreme environmental conditions. Monera includes the following organisms.
Archebacteria:
- They are the oldest organisms in this world.
- They survive in extreme environmental conditions.
- They are anaerobic and are the ancestor of present-day organisms, for example, Methanogenic bacteria.
Eubacteria:
- These bacteria represent the largest group of prokaryotic organisms.
- They are classified on the basis of cell wall structure example Gram positive and Gram negative in nature.
- They are both aerobic and anaerobic in nature and can also be classified on the basis of nutrition, the presence or absence of flagella, for example, Mycobacterium, and Vibrio.
Cyanobacteria:
- They are blue-green in color due to the stun presence of unique pigments called chlorophyll-a and c-phycocyanin.
- They are without flagella, grow in water, and do not have true sexual reproduction.
- They have nitrogen-fixing ability and may be used as biofertilizers, for example Nostoc, and Anabaena.
Mycoplasma :
1. They are bacteria-like organisms without any cell wall and so they are capable of slime changing their shape, also called Pleuronsdm Pneumonia Like Organisms (PPLO), for example, Mycoplasma.
Chlamydia:
- This organism is an intermediate between viruses and living organisms.
- It does not have true cells and causes parrot fever, for example, Chlamydia.
Actinomycetes:
- They are intermediate between fungi and bacteria.
- They are filamentous in nature and cut off thin-walled spores in chains.
- They are mostly soil-borne, and produce yes, antibiotics, for example, Streptomyces.
Question 4. Why are protozoa important? State its features.
Answer:
Protista
This group of organisms includes unicellular eukaryotes. It may include plants, animals, and fungi. It is a mixed group and includes the following organisms:
Unicellular green algae :
- The unicellular green algae has a cellular wall and chloroplast and food remains stored in the pyrenoid.
- They may be with or without flagella, for example, Chlamydomonas.
Diatoms:
- They are unicellular algae, having two mo valves formed of silica.
- They may be round or spindle-shaped, for example, Pennularia.
Myxomycetes:
- They are intermediate between fungi and protozoa.
- They have thread-like multi-nucleate structures and may be saprophytic or parasitic in nature, e.g. Plasmodiophora.
Dinoflagellates:
- They are unicellular, formed of 2 valves with a central groove, and the two flagella are arranged in such a way that they are oriented at right angles.
- They cause red tide in the sea, for example, Dinoclonium.
Protozoa :
- They are unicellular organisms similar to animal cells, having cell membranes, and moving with the help of cilia or pseudopodia.
- They may be saprophytic or parasitic in nature, for example, Entamoeba, and Paramoecium.
Question 5. What are the features of Conifer?
Answer:
Gymnosperms
These plants are big woody trees that usually bear cones containing naked seeds. They include the following:
Cycas :
- The plant looks like a dwarf coconut tree, with a monopodial stem and apical crown of leaves.
- The roots are coralloid in nature heavily infected with blue-green algae, for example, Cycas.
Conifer :
1. The trees are very large, the stem is woody, the leaves are spiny in nature, roots are infected with vesicular-arbuscular mycorrhizae, for example, Pinus.
Ginkgo:
The plants are endemic to Korea and Japan, small and shrub-like, with male cones and female megasporophyll having a pair of ovules, for example, Ginkgo.
Gnetum:
- The plant is a small tree.
- It is the most developed gymnosperm, having large leaves, male and female. reproductive cupules containing stamens and ovules protected by perianth.
- They are considered intermediate. between gymnosperm and angiosperm, for example, Gnetum.
Question 6. Why is moss considered a higher plant?
Answer:
Bryophytes
These plants are intermediate between terrestrial and aquatic conditions and that is why they are called amphibious plants.
Hepatics:
- These plants are thalloid in nature, growing along the surface of the soil.
- They are differentiated into basal storage zone and upper photosynthetic zone.
- They reproduce in the presence of water.
- They are so-called because the plant body looks like a liver, for example, Riccia).
Anthocerotae :
- These plants are intermediate between sad villa thalloid and leafy structures.
- The plant body has a multi-tier and long horn-shaped spore-bearing structure called a capsule and so these plants are also called hornworts, for example, Anthoceros.
Moss :
- These plants are leafy bryophytes.
- They have well-differentiated root, stem, and leaves and a well-differentiated spore-bearing structure called a capsule.
- The spores have a specific mechanism of dispersal, for example, Pogonatum.
Question 7. Distinguish between monocot and dicot.
Answer:
Angiosperms
- They are flowering plants mainly divided into two major groups, Monocotyledonae having a single cotyledon and Dicotyledonae having 2 cotyledons.
- These plants are the largest at present in the world.
Monocotyledonous plants:
- These plants have mostly non-woody stems, sheathing leaf bases, parallel venation, and trimerous flowers.
- Single cotyledon in the seed.
- Seeds with endosperm, for example, Paddy
Dicotyledonous plants: These plants have:
- Woody stem with massive secondary unglad n wood.
- Distinct stalked leaves with reticulate venation.
- Pentamerous flowers.
- Seeds non-endospermic.
- Seeds with two cotyledons example Mango, Bengal gram.
Leaf venation:
Leaf venation is the arrangement pattern of the veins on the leaf blade. Leaf venation is basically of two types.
1. Reticulate venation:
1. In this type, the veins branch and unite forming a complicated network. All the veins are interconnected, like the strands of the net. Leaves of Dicot plants generally have reticulate venation, e.g. Hibiscus.
2. Parallel venation:
In this type, the veins run parallel or nearly parallel to each other and are connected by smaller veins. Leaves of Monocot plants generally have parallel venation, for example, banana, and wheat.
On the basis of nature and the size of stems, plants may be classified as Herbs, Shrubs, and Trees.
Herbs:
- The plants are short with almost no branches and soft stems.
- They are either creepers or climbers.
- They are short in height. e.g. marigold.
Shrubs :
- The plants are woody but not too tall and have many branches and leaves.
- They look like bushes.
- They are of medium height, for example, china rose.
Trees:
- The plants are tall with strong stems.
- They have many branches and leaves, for example, mango.
Question 8. What are groups of protostomes? State their features.
Answer:
Animalia
The animal kingdom is very large with different multicellular organisms. Before going into classification, let us define and understand some terms connected with it.
1. Metazoa :
A group that comprises all animals having the body composed of cells differentiated into tissues and organs.
2. Eumetazoa :
It comprises all major animal groups except sponges and has truly organized tissues.
3. Acoelomata:
Animals have no coelom or body cavity.
4. Pseudocoelomata:
Animals have no true coelom but have a cavity in between the cuticle and visceral organs filled up with fluid.
5. Coelomata:
Animals have true coelom or body cavities lying in between the body wall and the alimentary canal.
6. Diploblastica:
Animals whose body is formed of ectoderm and endoderm cells only.
7. Triploblastica:
Animals whose body is formed of ectoderm, mesoderm, and endoderm cells.
These groups are discussed below:
Conceptual Questions on Conservation of Biodiversity
1. Invertebrate :
1. The animal has 2 layers.
Sponge:
- The animal is without the definite organization of tissues.
- They are sedentary in nature.
- The body is formed of a calcareous shell having multiple pores called ostia and an apical pore called osculum, for example, Sycon assumes.
Cnidaria:
- The animal is cylindrical in nature.
- It has two layers, ectoderm, and endoderm.
- The mouth is guarded by tentacles.
- They exhibit extracellular and intracellular digestion.
- The body consists of nematocysts, used for traping pray, for example, Hydra
Ctenophora:
- The animal has 2 layers.
- It is marine.
- It has a locomotory organ in the form of comb plates and specialized cells for trapping prey called Suzaid business caul oblast cells, for example, Beroe.
Platyhelminthes :
- The animal has a flattened body, the body is segmented.
- The animal is bisexual showing self-autumn fertilization, and survives as an endoparasite, for example, cedes to Taenia.
Aschelminthes :
- The animal is unisexual, having a pseudocolor.
- The female is larger than the male.
- They have a thick cuticle and survive as endoparasite, for example, Ascaris
Annelida :
- The animal is cylindrical in nature, with metameric segmentation.
- The animal may have red pigment haemoglobin but it is in the plasma.
- The blood circulation is closed.
- The animal is bisexual but is not capable of showing self-fertilization, for example, Pheretima posthuma (earthworm)
Arthropoda :
- This animal group is the largest having 4 sub-groups.
- They have open circulation with multi-chambered) sm heart.
- The sexes are different and fertilization is internal, example Periplaneta americana (cockroach)
Mollusca:
- The animal has a soft body covered by the mantle and well protected calcareous shell.
- The sexes are different and are intermediate between open and closed circulation, for example, Pila
Echinodermata:
- The animal has a calcareous endoskeleton with projections.
- They have blood circulation and a water vascular system.
- They are marine and feed from the sea bed i.e. benthonic inhabit, for example, Asterias (Starfish).
Hemichordata:
The animal is not under chordates, because they do not have notochord in the matured stage, e.g. Balanoglossus.
Urochordate:
- The notochord (an elastic rod-like structure situated immediately above the alimentary canal and covered by a sheath.) is limited to the tail region.
- The animal retains larval character in the adult stage and this phenomenon is called retrogressive metamorphosis example Ascidia
Cephalochordata:
- The animal has a notochord extended up to the head region.
- The animal has a tail fin and many characteristics as fish, for example, Amphioxus.
Real-Life Scenarios Involving Endemic Species
Question 9. What are chordates? Mention its characters.
Answer:
Animalia
The animal kingdom is very large with different multicellular organisms. Before going into classification, let us define and understand some terms connected with it.
1. Metazoa :
A group that comprises all animals having the body composed of cells differentiated into tissues and organs.
2. Eumetazoa :
It comprises all major animal groups except sponges and has truly organized tissues.
3. Acoelomata:
Animals have no coelom or body cavity.
4. Pseudocoelomata:
Animals have no true coelom but have a cavity in between the cuticle and visceral organs filled up with fluid.
5. Coelomata:
Animals have true coelom or body cavities lying in between the body wall and the alimentary canal.
6. Diploblastica:
Animals whose body is formed of ectoderm and endoderm cells only.
7. Triploblastica:
Animals whose body is formed of ectoderm, mesoderm, and endoderm cells.
These groups are discussed below:
1. Invertebrate :
1. The animal has 2 layers.
Sponge:
- The animal is without the definite organization of tissues.
- They are sedentary in nature.
- The body is formed of a calcareous shell having multiple pores called ostia and an apical pore called osculum, for example, Sycon assumes.
Cnidaria:
- The animal is cylindrical in nature.
- It has two layers, ectoderm, and endoderm.
- The mouth is guarded by tentacles.
- They exhibit extracellular and intracellular digestion.
- The body consists of nematocysts, used for traping pray, for example, Hydra
Ctenophora:
- The animal has 2 layers.
- It is marine.
- It has a locomotory organ in the form of comb plates and specialized cells for trapping prey called Suzaid business caul oblast cells, for example, Beroe.
Platyhelminthes :
- The animal has a flattened body, the body is segmented.
- The animal is bisexual showing self-autumn fertilization, and survives as an endoparasite, for example, cedes to Taenia.
Aschelminthes :
- The animal is unisexual, having a pseudocolor.
- The female is larger than the male.
- They have a thick cuticle and survive as endoparasite, for example, Ascaris
Annelida :
- The animal is cylindrical in nature, with metameric segmentation.
- The animal may have red pigment haemoglobin but it is in the plasma.
- The blood circulation is closed.
- The animal is bisexual but is not capable of showing self-fertilization, for example, Pheretima posthuma (earthworm)
Arthropoda :
- This animal group is the largest having 4 sub-groups.
- They have open circulation with multi-chambered) sm heart.
- The sexes are different and fertilization is internal, example Periplaneta americana (cockroach)
Mollusca:
- The animal has a soft body covered by the mantle and well protected calcareous shell.
- The sexes are different and are intermediate between open and closed circulation, for example, Pila
Echinodermata:
- The animal has a calcareous endoskeleton with projections.
- They have blood circulation and a water vascular system.
- They are marine and feed from the sea bed i.e. benthonic inhabit, for example, Asterias (Starfish).
Hemichordata:
The animal is not under chordates, because they do not have notochord in the matured stage, e.g. Balanoglossus.
Urochordate:
- The notochord (an elastic rod-like structure situated immediately above the alimentary canal and covered by a sheath.) is limited to the tail region.
- The animal retains larval character in the adult stage and this phenomenon is called retrogressive metamorphosis example Ascidia
Cephalochordata:
- The animal has a notochord extended up to the head region.
- The animal has a tail fin and many characteristics as fish, for example, Amphioxus.
Vertebrate:
These animals have a backbone called a vertebral column enclosing and protecting the spinal cord.
Cyclostomes:
The animal has a circular mouth with sharp teeth, for example, Myxine.
Pisces:
- The group includes all the fish.mat
- The fishes can be cartilaginous (chondrichthyans) or osteichthyan (bony fish), for example., Shark and Rohu.
Amphibia:
- This group of animals survives both on land and water.
- They have 3 chambered hearts.
- They go into hibernation or winter sleep, for example, Frogs.
Examples of Real-Life Applications of Biodiversity
Reptiles:
- The animal has an external epidermis.
- The animal is terrestrial.
- The limbs have digited claws.
- The animal is cold-blooded
- The ventricle is partially segmented except in crocodiles, which have 4 chambered hearts, for example, Snakes.
Aves:
- This group is represented by birds, which can be of 2 types, the running bird and the flying bird.
- They are warm-blooded.
- The heart is four-chambered.
- The body is covered with feathers, anterior pair of limbs are modified to produce wings.
- The lips are modified to produce toothless beaks, for example, Ostrich
Mammals:
- The animal group is most advanced with the presence of external hairs, pair of external pinna (ear).
- The brain is developed that controls all the major functions, the two lobes of the forebrain function in a well-coordinated manner because they are joined by the Corpus callosum.
- The mammary gland is functional in females for providing nourishment to the developing ones.
- The most primitive mammals are egg-laying Platypi and myg but the intermediate forms have a pouch, which stores the developing babies called marsupium example Kangaroo.
While the most developed mammals are placental mammals, where the last developing fetus is provided with nourishment from the mother’s body through the placenta, for example, Human, Ape.
Question 10. Why is mammal advanced over other animals?
Answer: Mammals have mammary glands, external ears, a diaphragm, a four-chambered heart, and a well-developed brain. They are warm-blooded animals and give birth to young ones.
Hence mammals are the highest group in the animal kingdom.