Animal kingdom Flashcards
Any plane that passes through the centre does not divide them into equal halves
Asymmetry
When
any plane passing through the central axis of
the body divides the organism into two identical
halves, it is called
Radial symmetry
Where the body can be divided into identical left and
right halves in only one plane.
Bilateral symmetry
Animals in which the cells are arranged in two
embryonic layers, an external ectoderm and
an internal endoderm, are called
Diploblastic
Those animals in which the developing embryo has a third germinal layer,
mesoderm, in between the ectoderm and endoderm, are called
Tripoblastic
The body cavity, which is lined
by mesoderm is called
Coelom
Animals
possessing coelom are called
Coelomates
Such a body cavity is called
pseudocoelom and the animals possessing them
are called
Pseudocoelomates
The animals in
which the body cavity is absent are called
Acoelomates
in earthworm, the body shows this pattern called metameric segmentation and the phenomenon is known as?
Metamerism
is a mesodermally derived rod-like structure formed on the
dorsal side during embryonic development in some animals
Notochord
Animals with
notochord are called
Chordates
those animals which do not form this structure (no notochord) are called
Non-chordates
Members of phylum porifera are known as
Sponges
They are generally marine and mostly
asymmetrical animals
Sponges
Sponges have a water
transport or canal system. Water enters through
minute pores
Ostia
Water enters through
minute pores (ostia) in the body wall into a central
cavity, spongocoel
Spongocoel
Water enters through
minute pores (ostia) in the body wall into a central
cavity, spongocoel, from where it goes out
through the
Osculum
Blank or collar cells line the spongocoel and the canals.
Digestion is intracellular
Choanocytes
The Sponge body is supported
by a skeleton made up of
Spicules
Sexes are not separate
i.e., eggs and sperms are produced by the same
individual.
Hermaphrodite
reproduce asexually by
fragmentation and sexually by formation of
gametes.
Sponges
They are aquatic, mostly marine, sessile or free-swimming, radially
symmetrical animals
Phylum Coelenterata (cnidaria)
is derived from cnidoblasts or cnidocytes (which contain the stinging capsules or
nematocysts) present on the tentacles and the body
Name of Cnidaria
are used
for anchorage, defense and for the capture of prey
Cnidoblasts
exhibit tissue level of organisation and are diploblastic.
Cnidarians
Cnidarians have a central
gastro-vascular cavity with a single opening, mouth on this. Digestion is intra and extracellular
Hypostome
have a skeleton composed of calcium carbonate
Corals
Cnidarians exhibit
two basic body forms called
Polyp and medusa
is a sessile and cylindrical form like Hydra, Adamsia, etc
Polyp
is umbrella-shaped and free-swimming like Aurelia or jelly fish.
Medusa
commonly known as sea walnuts or comb
jellies are exclusively marine, radially symmetrical, diploblastic organisms with tissue level of organisation.
Ctenophores
The body bears
eight external rows of this, which help in
locomotion
Ciliated comb plates
is well-marked in ctenophores
Bioluminescence
They have dorso-ventrally flattened body, hence are called
flatworms. These are mostly endoparasites found
in animals including human beings
Platyhelminthes
are bilaterally
symmetrical, triploblastic and acoelomate animals with organ
level of organisation
Flatworms
help in osmoregulation and excretion
Flame cells
The body of this is circular in
cross-section, hence, the name roundworms. They may be freeliving, aquatic
and terrestrial or parasitic in plants and animals.
Aschelminthes
have organ-system level of body organisation. They are bilaterally symmetrical,
triploblastic and pseudocoelomate animals
Roundworms
Sexes are separate, i.e., males and females are distinct.
DIoecious
Alimentary canal is complete with a well-developed
Muscular pharynx
They may be aquatic (marine and fresh water) or
terrestrial; free-living, and sometimes parasitic.
Phylum Annelida
Their body surface is
distinctly marked out into this and, hence, the phylum name
Annelida (Latin, annulus : little ring)
Segments/Metamers
Aquatic annelids like
Nereis possess lateral appendages,
which help in swimming
Parapodia
help in osmoregulation and excretion
Nephridia
An aquatic form, is dioecious
Nereis
Earthworms and leeches are
Monoecious
