NCERT Exemplar Class 9 Science Solutions Chapter 7 Diversity in Living Organisms

Question:1

Find out incorrect sentence
(a) Protista includes unicellular eukaryotic organisms
(b) Whittaker considered cell structure, mode and source of nutrition for classifying the organisms in five kingdoms
(c) Both Monera and Protista may be autotrophic and heterotrophic
(d) Monerans have well defined nucleus
Answer- (d)
Solution: R. H. Whittaker gave the five-kingdom classification that includes monera, protists, fungi, plants and animals. The kingdom Monera consists of unicellular, prokaryotic organsisms and is the most primitive group. They do not contain well-defined nucleus and cell organelles are absent.
The correct answer is d) Monerans have a well-defined nucleus

Question:2

Which among the following has specialised tissue for conduction of water?
(i) Thallophyta
(ii) Bryophyta
(iii) Pteridophyta
(iv) Gymnosperms
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (iii) and (iv)
(d) (i) and (iv)
Answer- (c)
Solution: The plant body of Thallophytes and Bryophytes is not differentiated into root, stem and leaves. The vascular bundles are absent in them.
Xylem is the true vascular bundle, a characteristic feature of land plants that include the Pteridophytes, Gymnosperms and Angiosperms, and helps in conducting water and minerals to the leaves from the soil.
Xylem and Phloem are found in Pteridophytes and they are further evolved in Gymnosperms and Angiosperms.
The correct answer is- c) 'iii and iv'

Question:3

Which among the following produce seeds?
(a) Thallophyta
(b) Bryophyta
(c) Pteridophyta
(d) Gymnosperms
Answer- (d)
Solution: Gymnosperms do not produce flowers. The male and female gametophytes are present in the sporophyte. They produce seeds which are not present inside an ovary and are called naked seeds. In bryophytes and pteridophytes, zygote produces sporophyte and there is no seed formation. In thallophytes, reproduction is mainly asexual and when sexual, it is isogamous, anisogamous or oogamous.
The correct answer is d)- Gymnosperms

Question:4

Which one is a true fish?
(a) Jellyfish
(b) Starfish
(c) Dogfish
(d) Silverfish
Answer- (c)
Solution: Jellyfish belong to phylum Cnideria, silverfish belong to phylum arthopoda and starfish belong to phylum Echinodermata. Dogfish come under the class Chondrichthyes of class Pisces. They have streamlined bodies with scales and have cartilaginous skeletons.
The correct answer is c)- Dogfish.

Question:5

Which among the following is exclusively marine?
(a) Porifera
(b) Echinodermata
(c) Mollusca
(d) Pisces
Answer- (b)
Solution: Echinodermata have a water vascular system. Example- Starfish. They are marine animals.
Porifera live in both saltwater and freshwater, e.g., Haliciona and Spongilla.
Mollusca can live on the rocky shore, freshwater, saltwater, etc. Pisces can be freshwater or saltwater.
Thus, the correct answer is b)- Echinodermata.

Question:6

Which among the following have open circulatory system?
(i) Arthropoda
(ii) Mollusca
(iii) Annelida
(iv) Coelenterata
(a) (i) and (ii)
(b) (iii) and (iv)
(c) (i) and (iii)
(d) (ii) and (iv)
Answer- (a)
Solution: The open circulatory systems pump blood into a cavity called hemocoel with the blood diffusing back to the circulatory system between cells. This system lacks a true heart or capillaries, E.g., Molluscs and Arthropods.
Annelida and Coelenterata have closed circulatory systems.
The correct answer is a)- (i) and (ii)

Question:7

In which group of animals, coelom is filled with blood?
(a) Arthropoda
(b) Annelida
(c) Nematoda
(d) Echinodermata
Answer- (a)
Solution: Annelida, Nematoda and Echinodermata don’t have blood and Arthropods coelom is filled with blood.
Annelids, arthropods and molluscs contain coelom that is a fluid-filled cavity present between the gut and mesoderm. The coelom of arthropods is filled with blood called as hemocoel. The circulating fluid in these organisms is called as hemolymph.
The correct answer is a)- Arthropoda

Question:8

Elephantiasis is caused by
(a) Wuchereria
(b) Pinworm
(c) Planarians
(d) Liver flukes
Answer - (a) Wuchereria
Solution: Wuchereria bancrofti is a filarial worm, a human parasite that causes Elephantiasis. This condition is also known as Filariasis and is transmitted to humans through mosquitoes. The effects of the disease is swelling of the limbs, genital areas, breasts, etc.
Pinworm is a common intestinal parasite and causes Enterobiasis. Planarians are non-parasitic flatworms. Liver flukes are flatworms that cause liver rot in humans.
The correct answer is a) Wucherreria.

Question:9

Which one is the most striking or (common) character of the vertebrates?
(a) Presence of notochord
(b) Presence of triploblastic condition
(c) Presence of gill pouches
(d) Presence of coelom
Answer- (a)
Solution: Kingdom Animalia are divided into chordates and non-chordates on the basis of presence or absence of notochord. The presence of triploblastic condition, presence of gill pouches and coelom is found in both vertebrates and invertebrates but Notochord is present only in invertebrates.
The correct answer is a) Presence of notochord

Question:10

Which among the following have scales?
(i) Amphibians
(ii) Pisces
(iii) Reptiles
(iv) Mammals
(a) (i) and (iii)
(b) (iii) and (iv)
(c) (ii) and (iii)
(d) (i) and (ii)
Answer-(c)
Solution: The bodies of amphibians do not contain scales on their body and their skin is permeable to allow the diffusion of gases.
The body of reptiles are covered with scales and have tough skin that provides them an adaptation in the extreme climate.
Fish have dermal scales while reptiles have horny epidermal scales.
The correct answer is c) (ii) and (iii).

Question:11

Find out the false statement
(a) Aves are warm blooded, egg laying and have four chambered heart
(b) Aves have feather-covered body, forelimbs are modified as wings and breathe through lungs
(c) Most of the mammals are viviparous
(d) Fishes, amphibians and reptiles are oviparous
Answer- (d)
Solution: The members of bony fishes are oviparous or viviparous while mammals are viviparous and cartilaginous fishes, reptiles and amphibians are oviparous. Aves are also oviparous. They have four chambered hearts filled with warm blood, bodies covered with feathers, respiration by lungs and forelimbs modified into wings.
The correct answer is d)- Fishes, amphibians and reptiles are oviparous

Question:12

Pteridophyta do not have
(a) root
(b) stem
(c) flowers
(d) leaves
Answer- (c)
Solution: Pteridophytes are vascular plants. They consists around 12,000 species of vascular plants that reproduce via spores and have neither seeds nor flowers, e.g., fern. The difference between pteridophytes and mosses is the presence of vascular vessels.
The correct answer is c) flowers

Question:13

Identify a member of porifera
(a) Spongilla
(b) Euglena
(c) Penicillium
(d) Hydra
Answer: (a)
Solution: Spongilla is a freshwater sponge and belongs to the family Spongillidae. They are found in lakes and streams. They belong to the phylum Porifera and consists of multicellular, unspecialized cells that can transform into other types.
Euglena is a unicellular organism and belongs to the kingdom Protista. Penicillium is a fungus and bears spores.
Hydra is a Coelenterata and a small, simple, radially symmetrical freshwater animal.
Thus, the correct answer is a)- Spongilla

Question:14

Which is not an aquatic animal?
(a) Hydra
(b) Jellyfish
(c) Corals
(d) Filaria
Answer- (d)
Solution: Hydra, jelly fish, corals are aquatic animals that live in water. Thus, they are called as aquatic animals. Roundworm is a nematode parasite found in both aquatic as well as terrestrial animals.
Filaria is a disease caused by Wuchereria and transmitted to humans through mosquitoes.
The correct answer is d)- Filaria.

Question:15

Amphibians do not have the following
(a) Three chambered heart
(b) Gills or lungs
(c) Scales
(d) Mucus glands
Answer- (c)
Solution: Amphibians are the organisms that live on both land and water. They have 3 chambered heart (2 auricles and 1 ventricle). They contain mucus glands which makes their body slimy. Gills and lungs are present for respiration. They do not contain scales.
The correct answer is- c) Scales

Question:16

Organisms without nucleus and cell organelles belong to
(i) fungi
(ii) protista
(iii) cyano bacteria
(iv) archae bacteria
(a) (i) and (ii)
(b) (iii) and (iv)
(c) (i) and (iv)
(d) (ii) and (iii)
Answer- (b)
Solution: Prokaryotes are the unicellular organisms e.g., Cyanobacteria and Archaebacteria. They belong to kingdom Monera. These organisms do not have a well-developed nucleus, nuclear membrane and cell organelles like mitochondria, etc. Fungi and protists are eukaryotes with nucleus and well-developed cellular organelles.
Thus, the correct answer is b)- (iii) and (iv)

Question:17

Which of the following is not a criterion for classification of living organisms?
(a) Body design of the organism
(b) Ability to produce one’s own food
(c) Membrane bound nucleus and cell organelles
(d) Height of the plant
Answer- (d)
Solution: Living organisms are classified on different criteria like- nature of cell, number of cells, mode of nutrition, body design, presence or absence of nucleus, presence of conducting tissue etc. The height of a plant is not considered as criterion for classification of organisms.
The correct answer is- d) the height of the plant

Question:18

The feature that is not a characteristic of protochordata?
(a) Presence of notochord
(b) Bilateral symmetry and coelom
(c) Jointed legs
(d) Presence of circulatory system
Answer- (c)
Solution: Arthropods consists of jointed legs. It includes most of the insects. Protochordata are invertebrates, marine animals. They are triploblastic with the bilaterally symmetric body and coelom. They have notochord at some stage of life.
The correct answer is c) jointed legs.

Question:19

The locomotory organs of Echinodermata are
(a) tube feet
(b) muscular feet
(c) jointed legs
(d) parapodia
Answer- (a)
Solution: Echinodermata consists of a water vascular system. They contain complex system of water-containing tubes and bladders which pass through pores in the skeleton. These tubes look like feet from outside and they also help in locomotion, exchange of gases and feeding.
The correct answer is a) 'Tube feet'.

Question:20

Corals are-
(a) Poriferans attached to some solid support
(b) Cnidarians, which are solitary living
(c) Poriferans present at the sea bed
(d) Cnidarians that live in colonies
Answer-(d)
Solution: Corals belong to phylum Cnidaria. They are marine invertebrates and live in colonies of identical polyps held together by calcium carbonate. The coral reefs have inhabited the oceans and secrete calcium carbonate to form a hard skeleton.
The correct answer is d) Cnidarians that live in colonies

Question:21

Who introduced the system of scientific nomenclature of organisms?
(a) Robert Whittaker
(b) Carolus Linnaeus
(c) Robert Hooke
(d) Ernst Haeckel
Answer- (b)
Solution: Carolus Linnaeus introduced the scientific sytem of naming organisms called as binomial nomenclature. It is a simplified method. Binomial nomenclature gives each organism a scientific name that has two parts. The first part is a Genus and the second part is Species. It is always written in Italics.
The correct answer is b)- Carolus Linnaeus

Question:22

Two chambered heart occurs in
(a) crocodiles
(b) fish
(c) aves
(d) amphibians
Answer - (b)
Solution: Crocodiles and aves have 4-chambered hearts while amphibians have 3 chambered hearts. Fishes have two chambered hearts- one auricle and one ventricle. The auricle is responsible for taking in blood from the body and the ventricle pumps out the blood that has entered the heart through the gills and gives fresh oxygen to the blood.
The correct answer is b)- fish

Question:23

Skeleton is made entirely of cartilage in
(a) Sharks
(b) Tuna
(c) Rohu
(d) None of these
Answer- (a)
Solution: The skeleton of cartilaginous fish is made up of cartilage. They are also called as Osteichthyes
e.g., Sharks whereas Tuna and Rohu are bony fishes with a bony structure. They are also called as Chondrichthyes
The correct answer is a)- Sharks

Question:24

One of the following is not an Annelid
(a) Nereis
(b) Earthworm
(c) Leech
(d) Urchins
Answer-(d)
Solution: Nereis, earthworm and leech belong to phylum Annelida. It is a group of animals having a segmented body without spines, and their body surface is covered with cuticles
Urchin belongs to the phylum Echinodermata. It is a marine animal with a globelike shape and radial symmetry. Its body is covered with long spines for protection.
The correct answer is- d) Urchins.

Question:25

The book Systema Naturae was written by
(a) Linnaeus
(b) Haeckel
(c) Whittaker
(d) Robert Brown
Answer- (a)
Solution: Carolus Linnaeus wrote the book 'Systema Naturae'. It was one of his major works. He introduced the system of naming organisms- binomial nomenclature. Its first edition was published in 1735.
Haeckel coined the term -ecology.
Whittaker proposed the five-kingdom classification, i.e., Monera, Protista, Fungi, Plantae and animalia.
Robert Brown discovered the nucleus in the cell.
The correct option is a) Linnaeus

Question:26

Karl Von Linne was involved with which branch of science?
(a) Morphology
(b) Taxonomy
(c) Physiology
(d) Medicine
Answer- (b)
Solution: Karl Von Linne is also known as Carl Linnaeus. He made significant contributions to the naming and classification of living organisms and proposed the binomial system of nomenclature, which is a formal system of naming living organisms. It consists of 2 parts- the first part is Genus and second part is Species. It is always written in italics.
The correct answer is b) Taxonomy.

Question:27

Real organs are absent in
(a) Mollusca
(b) Coelenterata
(c) Arthropoda
(d) Echinodermata
Answer- (b)
Solution: Coelenterates have tissue level organization and they lack real organs. They are multicellular, diploblastic and acoelomate animals with radial symmetry. They may be freshwater or marine.
Mollusca, Arthropoda and Echinodermata have organ levels of organisation.
The correct answer is b) Coelenterata

Question:28

Hard calcium carbonate structures are used as skeleton by
(a) Echinodermata
(b) Protochordata
(c) Arthropoda
(d) Nematoda
Answer- (a)
Solution: A Sea urchin belongs to the phylum Echinodermata. These are spiny skinned organisms found in marine water. They are triploblastic and have a coelomic cavity. They produce calcium carbonate plates that fit together tightly.
The correct answer is a)Echinodermata

Question:29

Differentiation in segmental fashion occurs in
(a) Leech
(b) Starfish
(c) Snails
(d) Ascaris
The answer is (a) Leech
Solution: Leech is a member of the Annelida phylum. Their body surface is divided into segments that are identical to each other and they contain a set of organs in each segment. Their body is also covered with cuticles. Starfish belongs to Echinodermata, and snail belongs to Mollusca.
The correct answer is a) Leech

Question:30

In taxonomic hierarchy family comes between
(a) Class and Order
(b) Order and Genus
(c) Genus and Species
(d) Division and Class
Answer- (b)
Solution: The Living organisms are arranged in the following hierarchy:
Species ---- Genus ---- Family ---- Order ---- Class ---- Phylum ---- Kingdom
The correct option is (b)- Order and Genus

Question:31

5-Kingdom classification has given by
(a) Morgan
(b) R. Whittaker
(c) Linnaeus
(d) Haeckel
The answer is (b)
Solution: R. Whittaker gave a 5-kingdom classification. It includes Monera, Protista, Fungi, Plantae and Animalia. This classification was based on cell structure, cellular organisation, mode of nutrition etc.
The correct option is (b) R. Whittaker

Question:32

Well defined nucleus is absent in
(a) blue green algae
(b) diatoms
(c) algae
(d) yeast
Answer-(a)
Solution: Diatoms are also known as phytoplanktons with secondary chloroplasts derived from an endosymbiotic red alga. Algae is an eukaryotic organism. It consists of the microscopic unicellular Chlorella and the diatoms to multicellular kelps, the large brown alga. Yeast is a eukaryotic organism belonging to the kingdom Fungi. Blue-green algae or Cyanobacteria, is the most primitive photosynthetic bacteria. These are unicellular and do not contain any well-defined nucleus.
Hence, the correct answer is a)blue-green algae

Question:33

The ‘Origin of Species’ is written by
(a) Linnaeus
(b) Darwin
(c) Hackel
(d) Whittaker
Answer- (b)
Solution: ‘Origin of Species' is a work of scientific literature by Charles Darwin. It was published on 24th November 185. The full title of the book was 'On the Origin of Species by Means of Natural Selection or the Preservation of Favoured Races in the Struggle for Life'.
The correct answer is (b)- Darwin.

Question:34

Meena and Hari observed an animal in their garden. Hari called it an insect while Meena said it was an earthworm. Choose the character from the following which confirms that it is an insect.
(a) Bilateral symmetrical body
(b) Body with jointed legs
(c) Cylindrical body
(d) Body with little segmentation
The answer is (b) Body with jointed legs
Solution: Arthropoda consist of insects that make up around 75% of the phylum Arthropoda. They can live in different habitats and can crawly, fly, jump and swim. Arthropoda has been derived from a Greek word- arthron meaning 'joint' and pous meaning 'foot'. Hence, insects are basically animals with jointed legs.
The correct answer is b) 'Body with jointed legs’.

NCERT Exemplar Class 9 Science Solutions Chapter 7 Short Answer

Question:35

Write true (T) or false (F)
(a) Whittaker proposed five kingdom classification.
(b) Monera is divided into Archaebacteria and Eubacteria.
(c) Starting from Class, Species comes before the Genus.
(d) Anabaena belongs to the kingdom Monera.
(e) Blue green algae belongs to the kingdom Protista.
(f) All prokaryotes are classified under Monera.
Answer:

a-True- The 5 kingdom classification given by Whittaker is the most accepted one.
b- True- Monera consists of unicellular, prokaryotic organisms.
c- False- Genus comes before the species according to the Linnaeus system.
d-True- It is a genus of the cyanobacteria which belongs to kingdom Monera.
e-False- They obtain their energy by the process of photosynthesis.
f- True- all the prokaryotes i.e., bacteria and blue green algae belongs to kingdom-Monera.

Question:36

Fill in the blanks
(a) Fungi shows———mode of nutrition.
(b) Cell wall of fungi is made up of ———.
(c) Association between blue green algae and fungi is called as———.
(d) Chemical nature of chitin is ———.
(e) ———has smallest number of organisms with maximum number of similar characters
(f) Plants without well differentiated stem, root and leaf are kept in ———.
(g) ———are called as amphibians of the plant kingdom.
Answer:

1. Fungi show Saprophytic mode of nutrition.
2. The cell wall of fungi is made up of Chitin.
3. The association between blue green algae and fungi is called Lichens.
4. The chemical nature of chitin is Carbohydrate.
5. Species have the smallest number of organisms with a maximum number of similar characters.
6. Plants without well-differentiated stem, root and leaf are kept in Thallophyta.
7. Bryophytes are called amphibians of the plant kingdom.

Question:37

You are provided with the seeds of gram, wheat, rice, pumpkin, maize and pea. Classify them whether they are monocot or dicot.
Answer:

Monocot consists of one seed leaf inside the seed coat. Dicots have two seed leaves inside the seed coat.
Gram-Dicot
Wheat-Monocot
Rice- Monocot
Pumpkin- Dicot
Maize- Monocot
Pea—Dicot

Question:38

Match items of column (A) with items of column (B)

Answer:

a-B, b- A, c- D, d-C, e-F, f-E, g-G

1. Naked seed – Gymnosperm is a type of phanerogam and bears naked seeds.
2. Covered seed – Angiosperm have seeds present inside their fruits.
3. Flagella – Euglena is a eukaryotic, autotrophic organism that has cilia or flagella present on it.
4. Marchantia – Bryophytes like Marchantia have a well-developed plant body without specialized vascular tissues.
5. Marsilea – Pteridophyta like Marsilea have a well-developed plant body with specialized vascular tissues.
6. Cladophora – Thallophyta like Cladophora do not have a well-differentiated plant body.
7. Penicillium – Fungi like Penicillium is are heterotrophic eukaryotic organisms.

Question:39

Match items of column (A) with items of column (B)

Answer:
a-C, b-B, c-C, d-A, e-E, f-F
Solution:

1. Porifera- These animals have pores all over the body, which helps to circulate the water throughout the body and brings food and oxygen.
2. Coelenterata- They are diploblastic animals, and their body is made up of two layers- one layer makes up cells on the outside of the body, and other makes up the inner lining of the body.
3. Annelida- This group of animals show metameric segmentation. Metameric segmentation is a longitudinal division of the body into a similar section of parts.
4. Arthropoda- It includes all the animals with jointed legs.
5. Mollusca- They are soft-bodied animals with bilateral symmetry.
6. Echinodermata- These are spiny-skinned marine animals.

Question:40

Classify the following organisms based on the absence/presence of true coelom (i.e., coelomate, pseudocoelomate and acoelomate)
Spongilla, Sea anemone, Planaria, Liver fluke
Wuchereria, Ascaris, Nereis, Earthworm,
Scorpion, Birds, Fishes, Horse.
Answer:

• A coelomate has a body cavity between the body wall and the digestive tract.
• Pseudocoelomate has a fluid-filled body cavity between the endoderm and the mesoderm.
• Acoelomates do not have a body cavity or a coelom.

Question:41

Endoskeleton of fishes are made up of cartilage and bone; classify the following fishes as cartilagenous or bony
Torpedo, Sting ray, Dog fish,
Rohu, Angler fish, Exocoetus.
Answer:

The skeleton of bony fish is made of bones, while as cartilaginous fish is made of only cartilage.
Cartilaginous- Torpedo, Stingray, Dogfish
Bony- Rohu, Angler fish, Exocoetus

Question:42

Classify the following based on number of chambers in their heart.
Rohu, Scoliodon, Frog, Salamander, Flying lizard, King Cobra, Crocodile, Ostrich, Pigeon, Bat, Whale
Answer:

• Rohu – 2 chambered

• Scoliodon – 2 chambered

• Frog – 3 chambered

• Salamander – 3 chambered

• Flying lizard – 3 chambered

• King Cobra – 3 chambered

• Crocodile – 4 chambered

• Ostrich – 4 chambered

• Bat – 4 chambered

• Whale – 4 chambered

Question:43

Classify Rohu, Scolidon, Flying lizard, King Kobra, Frog, Salamander, Ostrich, Pigeon, Bat, Crocodile and Whale into the cold blooded/warm blooded animals.
Answer:

Cold-blooded animals cannot control their body temperature and therefore become sluggish in cold weather, while as warm-blooded animals maintain their constant body temperature. The classification of animals as warm and cold blooded are as under-
Cold blooded animals- Rohu, Scolidon, Flying lizard, King Cobra, Frog, Salamander, Crocodile
Warm Blooded animals- Ostrich, Pigeon, Bat, Whale

Question:44

Name two egg laying mammals.
Answer:

Egg laying animals are called as viviparous. Billed platypus and the echidna are the egg-laying mammals, called as monotremes.

Question:45

Fill in the blanks
(a) Five kingdom classification of living organisms is given by ———.
(b) Basic smallest unit of classification is ———.
(c) Prokaryotes are grouped in Kingdom ———.
(d) Paramecium is a protista because of its ———.
(e) Fungi do not contain ———.
(f) A fungus ——— can be seen without microscope.
(g) Common fungi used in preparing the bread is ———.
(h) Algae and fungi form symbiotic association called ———.
Answer:

(a) The five kingdom classification of living organisms is given by Robert Whittaker.
(b) The Basic smallest unit of classification is Species.
(c) Prokaryotes are grouped in the Kingdom Monera.
(d) Paramecium is a protista because of its Eukaryotic unicellular morphology.
(e) Fungi do not contain Chlorophyll.
(f) A fungus Mushroom can be seen without a microscope.
(g) A Common fungi used in preparing bread is Yeast.
(h) Algae and fungi form a symbiotic association called Lichens.

Question:46

Give True (T) and False (F)
(a) Gymnosperms differ from Angiosperms in having covered seed.
(b) Non flowering plants are called Cryptogamae.
(c) Bryophytes have conducting tissue.
(d) Funaria is a moss.
(e) Compound leaves are found in many ferns.
(f) Seeds contain embryo.
Answer:

(a) True- Gymnosperms are plants which are characterized by naked seeds. While in the angiosperm plant, the embryo is covered in a hard coating called as a seed.
(b) True- A cryptogam is a plant that reproduces by spores, without flowers or seeds.
(c) False- Bryophytes do not have conducting tissues. They are non-vascular terrestrial plants.
(d) True - Funaria is a moss and bears male and female sex organs at the apices of two different shots of the same plant.
(e) True- All ferns have pinnate leaves with one central axis and smaller branches called as frond.
(f) True- The embryo is the fertilised ovule with an immature plant from which a new plant will grow under proper conditions.

Question:47

Give examples for the following
(a) Bilateral, dorsiventral symmetry is found in———.
(b) Worms causing disease elephantiasis is———.
(c) Open circulatory system is found in———where coelomic cavity is filled with blood.
(d) ———are known to have pseudocoelom.
Answer:

(a) Bilateral, dorsiventral symmetry is found in Liver Fluke.
(b) Worms causing disease elephantiasis is Filarial worm.
(c) Open circulatory system is found in Arthropods where coelomic cavity is filled with blood.
(d) Nematodes are known to have pseudocoelom.

Question:48

Label a, b, c and d. given in Fig. 7.1 Give the function of (b)

Answer:

a.Dorsal fin- present along the mid-dorsal line.
b.Caudal fin- found at the tip of the tail.
c. Pelvic fin- present in pair, at the posterior position of the fish body.
d. Pectoral fin- present in pair, at the anterior position of the fish body.

Question:49

Fill in the boxes given in Fig. 7.2 with appropriate characteristics/plant group (s)

Answer:

1. Thallophyta- It includes primitive life forms of a plant which have a simple plant body. E.g., Ulothrix, Spirogyra, Cladophara
2. Vascular tissue without specialization is present in thallophytes and bryophytes.
3. Pteridophyta- These vascular plants reproduce using spores.
4. Phanerogams- These are plants that have special structures for reproduction and produce seeds.
5. Bare naked seeds- These belong to gymnosperms. E.g. conifers.
6. Angiosperms-These are the vascular plants and have a stem, roots and leaves.
7. Seeds with two cotyledons- These are called as dicotyledons e.g. beans.
8. Monocots- The seeds with one cotyledon, e.g. rice, maize

NCERT Exemplar Class 9 Science Solutions Chapter 7 Long Answer

Question:50

Write names of few thallophytes. Draw a labelled diagram of Spirogyra.
Answer:

Thallophyta belong to the plant kingdom. It includes primitive life forms of a plant which have a simple plant body. E.g., Ulothrix, Spirogyra, Cladophara, Ulva and Chara are a few of the examples of Thallophytes

Question:51

Thallophyta, bryophyta and pteridophyta are called as ‘Cryptogams’. Gymnosperms and Angiosperms are called as ‘phanerogams’. Discuss why? Draw one example of Gymnosperm.
Answer:

Thallophyta, bryophyta and pteridophyta belong to the sub kingdom called Cryptogamae. They are seedless and flowerless plants. Their reproductive organs are very inconspicuous, and are therefore called as ‘cryptogams’, or ‘those with hidden reproductive organs’. They reproduce with the help of spores.
Example: Pinus
Gymnosperms and angiosperms belong to sub-kingdom called phanerogamae. These are the flowering plants with well-differentiated reproductive parts that produces seeds.
Example: Cycas

Question:52

Define the terms and give one example of each
(a) Bilateral symmetry
(b) Coelom
(c) Triploblastic
Answer:

1. Bilateral symmetry- The organisms whose body shapes are mirror images of each other if cut along a middle line. They have identical right and left halves in only one plane. E.g., Annelids.

2. Coelom- It is a body cavity filled with fluid with a complete lining derived from mesoderm. e.g. Chordates.

3. Triploblastic- The animals with 3 embryonic germ layers (mesoderm, ectoderm, endoderm) from which differentiated tissues are made are called triploblastic organisms. Ex: Starfish.

Question:53

You are given leech, Nereis, Scolopendra, prawn and scorpion; and all have segmented body organisation. Will you classify them in one group? If no, give the important characters based on which you will separate these organisms into different groups.
Answer:

All of these organisms possess segmented body organisation but they do not belong to a single group of organisms. Leech and Nereis belong to phylum Annelida but Scolopendra, prawn and scorpion belong to phylum Arthropoda.
Annelids have a metamerically segmented body i.e., the body is divided into more or less similar types of segments and external segmentation corresponds to the internal segmentation i.e. body cavity is also segmented through septa. The locomotory organs present in them are suckers in case of leech and parapodia in case of Nereis. They possess a close blood vascular system, and their excretory organs are nephridia.
Arthropods have jointed legs, open circulatory system, body is ocvered with chitin and tracheal system for respiration.

Question:54

Which organism is more complex and evolved among Bacteria, Mushroom and Mango tree. Give reasons.
Answer:

Bacteria are a unicellular organism while mushrooms and mango trees are multicellular.
But Mango tree is more complex and evolved organism amongst all because it is eukaryotic, multicellular, autotrophic plant found on the land. It belongs to the class angiosperm and its seeds are present within the fruit. It produces flowers and the reproductive organs are present in it.
While bacteria is a prokaryotic unicellular organism and mushrooms belong to the class fungi and are heterotrophic thallophytes without any differentiation of stem leaves and roots, vascular tissues and embryonic stage is absent.

Question:55

Differentiate between flying lizard and bird. Draw the diagram.
Answer:

Question:56

List out some common features in cat, rat and bat.
Answer:

The cat, rat and bat belong to the class Mammalia. The common characteristic features between them are as under-

• All of them are multicellular and have nucleus present in their cells.

• Their mode of nutrition is heterotrophic in nature.

• All have notochord present in them.

• The presence of four-chambered heart in them.

• They have a dorsal nerve cord.

• All are triploblastic in nature.

• They are coelomate.

• They are viviparous i.e. give birth to the offsprings and have mammary glands present to feed their offsprings.

Question:57

Why do we keep both snake and turtle in the same class?
Answer:

Snakes and turtles both belong to the class Reptilia. They have common characteristic features which are as under-

• They are cold-blooded animals.

• They have skin without glands.

• They have scales present on their body.

• They respire with the help of lungs.

• They have a three-chambered heart

• Both of them are oviparous, i.e., egg-laying animals.

• They have hard-shelled eggs and they need not to lay them in water