Diversity in living organisms
Top definitions
1)
Classification – The method of arranging organisms into
groups on the basis of similarities and differences.
2)
Characteristic – A distinguishing feature of an
individual or group.
3)
Evolution – A gradual and continuing process of change
in body design of organisms, occurring over a period of time due to various
factors, which leads to better survival of organisms as well as development of
new species.
4)
Biodiversity – The variety of life forms found in a
particular region.
5)
Regions of megadiversity – Regions rich in diversity of
plant and animal life.
6)
Habitat – The natural abode of an animal or plant.
7)
Species – It refers to all organisms that are similar
enough to breed and perpetuate.
8)
Saprophytes – Organisms obtaining their nourishment
from dead and decaying organic material.
9)
Lichens - Symbiotic associations of certain fungi with
blue-green algae.
10)
Cotyledon - Embryonic leaf in seed-bearing plants.
11)
Monocots – Plants with seeds having a single cotyledon.
12)
Dicots - Plants with seeds having two cotyledons.
13)
Bilateral symmetry- Symmetrical arrangement of an
organism along a central axis, so that the body is divided into equivalent
right and left halves by only one plane.
14)
Radial symmetry –A type of symmetry having only one
body axis, through which the body can be divided in multiple planes to give
mirror
image
halves
OR
A form of
symmetry, in which dividing the animal's body in any direction along the
central axis would always result in 2 identical halves being obtained.
15)
Notochord - A long flexible rod-shaped support
structure that runs along the back of the animal separating the nervous tissue
from the gut.
16)
Nerve cord - A dorsal tubular cord of nervous tissue
above the notochord of a chordate.
17)
Diploblastic animals - Animals having 2 primary germ
layers i.e.
ectoderm and
endoderm in the embryo.
18)
Triploblastic animals - Animals having 3 primary germ
layers i.e.
ectoderm,
mesoderm and endoderm in the embryo.
19)
Ectoderm – The outermost germ layer of multicellular animals that develops into
skin and nervous tissue.
20)
Endoderm - The innermost germ layer of multicellular animals that develops into the
lining of the digestive and respiratory systems.
21)
Mesoderm - The middle germ layer that develops into muscle and bone and cartilage
and blood and connective tissue.
22)
Acoelomates – Animals lacking a body cavity between
their gut and body wall.
23)
Coelom - A fluid filled cavity formed within the
mesoderm, in which well-developed organs can be accommodated.
24)
Pseudocoelom - An internal body cavity of some
primitive invertebrates, similar to a coelom but lacking a mesodermal lining.
25)
Coelenteron – The central gastrovascular cavity of a
coelenterate animal.
26)
Cold-blooded organisms – Organisms whose body
temperature varies according to the external environmental temperature.
27)
Warm-blooded organisms – Organisms whose internal body
temperature is dependent upon its metabolic processes and is maintained at a
constant level.
28)
Oviparous animals – Animals that lay eggs.
29)
Viviparous animals – Animals giving birth to live young
ones.
30)
Binomial nomenclature – The scientific system of naming
each species of organism with two names, a genus name and a species name.
