What is a keystone species?
A species which makes up only a small proportion of the total biomass of a community, yet has a huge impact on the community's organization and survival.
A common species that has plenty of biomass, yet has a fairly low impact on the community's organization.
A rare species that has minimal impact on the biomass and on other species in the community.
A dominant species that constitutes a large proportion of the biomass and which affects many other species.
Annual migration does not occur in the case of:
Salmon
Siberian crane
Salamander
Arctic tern
Reduction in vascular tissue, mechanical tissue and cuticle is characteristic of:
Xerophytes
Mesophytes
Epiphytes
Hydrophytes
Choose the correct match Bladderwort ,sundew ,venus fly trap
Nepenthes ,Dionea , Drosera
Nepenthes , Utricularia , Vanda
Utricularia , Drosera , Dionea
Dionea , Trapa , Vanda
There is no life on moon due to absence of
O2
water
light
temperature
A species is considered as:
Artificial concept of human mind which cannot be defined in absolute terms .
Real units of classification devised by taxonomists .
Real basic units of classification
The lowest units of classification
Consider the following statements concerning food chains:
(A) Removal of 80% tigers from an area resulted in greatly increased growth of vegetation .
(B) Removal of most of the carnivores resulted in an increased population of deers .
(C) The length of food chains is generally limited to 3-4 trophic levels due to energy loss .
(D)The length of food chains may vary from 2 to 8 trophic levels .
Which two of the above statements are correct ?
B and C
C and D
A and D
A and B
Niche overlap indicates:
Active cooperation between two species.
Two different parasites on the same host.
Sharing of one or more resources between the two species.
Mutualism between two species.
World Summit on Sustainable Development (2002) was held in:
Brazil
Sweden
Argentina
South Africa
Mycorrhiza is an example of:
Endoparasitism
Decomposers
Symbiotic relationship
Ectoparasitism
