When any plane passing through the central axis of the body divides the organism into two identical halves, the organism is called ___________.
radially symmetrical
bilaterally symmetrical
asymmetrical
metamerically segmented
Correct Answer :
A. radially symmetrical
Radial symmetry is found in coelenterates, ctenophores and echinoderms. The right and left, or the dorsal and ventral sides, in such symmetry are not differentiated. This type of symmetry is advantageous to sessile (attached) animals as they can feed from all directions.
Related Questions
Refer the following animals and identify those which have a fluid filled body cavity with a complete lining derived from mesoderm.
(i) Sycon (ii) Butterfly
(iii) Nereis (iv) Sea fan
(v) Scorpion (vi) Pila
(i) and (iii) only
(ii) and (iv) only
(ii), (iii), (v) and (vi) only
All of these
A common characteristic of all vertebrates without exception is
the division of body into head, neck, trunk and tail.
body covered with exoskeleton.
the possession of two pairs of functional appendages.
the presence of well- developed skull.
The given figures (A & B) shows the germinal layer. The animals having structures shown in the figures are respectively called
diploblastic, triploblastic
triploblastic, diploblastic
diploblastic, diploblastic
triploblastic, triploblastic
Refer the figures A, B and C and choose the correct option which shows animals that regulate buoyancy with the help of air bladder.
A and B
A and C
B and C
All of the above.
Which of the following is a living fossil?
Balanoglossus
Echinus
Ancylostoma
Limulus
Which of the following feature in birds indicates their reptilian ancestory ?
Eggs with a calcareous shell
Scales on their hind limbs
Four-chambered heart
Two special chambers-crop and gizzard in their digestive tract
Which of the following is a chordate feature and not shared by the non-chordates ?
Metamerism
Axial organization
Bilateral symmetry
Pharyngeal gill slits
Which of the following characteristics is correct for reptilia?
Body covered with dry and cornified skin, scales over the body are epidermal, they do not have external ears.
Body is covered with moist skin and is devoid of scales, the ear is represented by a tympanum, alimentary canal, urinary and reproductive tracts open into a common cloaca.
Fresh water animals with bony endoskeleton and airbladder regulate buoyancy.
Marine animals with cartilaginous endoskeleton and body is covered with placoid scales.
Which of the following is not a chordate character?
Presence of paired pharyngeal gill slits
Ventral heart
Solid and ventral nerve cord
Presence of post-anal tail
Which of the following is not a characteristic feature of kingdom animalia ?
Storage of carbohydrates as starch.
Multicellularity.
Obtaining nutrients by ingestion.
Having eukaryotic cells without walls.
Identify the figures A, B and C and choose the correct option.
A - Male Ascaris, B - Hirudinaria (leech), C- Nereis
A - Female Ascaris, B - Nereis, C-Hirudinaria (leech)
A - Female Ascaris B- Hirudinaria (leech), C - Nereis
A - Male Ascaris, B - Nereis, C- Hirudinaria (leech)
In amphibians, respiration occurs through
gills
lungs
skin
all of these
Animals like annelids, arthropods, etc. where the body can be divided into identical left and right halves in only one plane, exhibit___________symmetry.
radial
bilateral
asymmetrical
non- symmetrical
Which of the following statements is without exception in sponges ?
They all have calcareous spicules.
They have high regenerative power.
They are found only in marine water.
They are all radially symmetrical.
In ctenophora, the body bears _______ external rows of ciliated comb plates, which help in locomotion.
five
six
seven
eight
Which of the following features distinguish mammals from other vertebrates ?
Hairy skin and oviparity
Hairy skin and mammary glands
Mammary glands and teeth
Pinna and teeth
Which of the following phylum is being described by the given statements?
(i) These are primitive multicellular animals and have cellular level of organization.
(ii) Digestion is intracellular.
(iii) They have a water transport or canal system.
(iv) They reproduce asexually by fragmentation and sexually by formation of gametes.
Porifera
Ctenophora
Coelenterata
Platyhelminthes
The given figure shows some characteristic features marked as chordates. Identify the correct labelling A,B,C and D.
A-Notochord; B-Post-anal part; C-Gill slits; D-Nerve cord
A-Nerve cord; B-Notochord; C-Post-anal part; D-Gill slits
A-Notochord; B-Nerve cord; C-Gill slits; D-Post-anal part
A-Gill slits; B-Post-anal part; C-Nerve cord; D-Notochord
Which of the following statements is incorrect ?
Prawn has two pairs of antennae.
Nematocysts are characteristic feature of the phylum cnidaria.
Millipedes have two pairs of appendages in each segment of the body.
Animals that belong to phylum porifera are exclusively marine.
Which of the following possesses poison sting and belongs to class chondrichthyes?
Labeo
Myxine
Clarias
Trygon
Which of the following group of animals belongs to the same phylum?
Earthworm, pinworm, tapeworm
Prawn, scorpion, Locusta
Sponge, Sea anemone, starfish
Malarial parasite, Amoeba, mosquito
In phylum echinodermata, the adult echinoderms are ______A__________ but larvae are _______B______ .
A radially symmetrical; B bilaterally symmetrical
A bilaterally symmetrical; B radially symmetrical
A bilaterally symmetrical; B asymmetrical
A metamerically segmented; B asymmetrical
In phylum arthropoda, excretion takes place through
nephridia
flame cells
malphigian tubules
gills
Which one of the following statement regarding coelom of given animals is correct?
Round worms (aschelminthes) are pseudocoelomates.
Molluscs are acoelomates.
Insects are pseudocoelomates.
Flatworms (platyhelminthes) are coelomates.
When any plane passing through the central axis of the body divides the organism into two identical halves, the organism is called ___________.
radially symmetrical
bilaterally symmetrical
asymmetrical
metamerically segmented
Which of the following animal contains respiratory organs like, gills, book gills, book lungs or tracheal system?
Click to check answer
Click to check answer
Click to check answer
Click to check answer
The given figures of animals (A & B) are distinguished on the basis of symmetry. Select the correct option which shows the type of symmetry and its description against the animals.
A : Biradial, organisms is divided into unequal halves by any plane through the central axis.
B: Bilateral, body is divided into equivalent right and left halves by only one plane.
A: Asymmetrical, organisms is not divided into equal halves by any plane through the central axis.
B: Radial, in which any plane passing through the central axis of the body divides the organism into two identical halves.
The figure given below shows the germinal layers marked as A, B, C and D. Identify the label showing undifferentiated layer and its location?
A, Between B & C
B, Between A & C
C, Between C & D
D, Between A & B
__________ is responsible for maintaining the current of water in sponge.
Osculum
Porocytes
Spongocoel
Choanocytes
A file like rasping organ for feeding, called radula, present in the phylum __________.
arthropoda
mollusca
echinodermata
chordata