Plants such as Prosopis, Acacia and Capparis represent examples of tropical
Flora of thorn forests include Prosopis cineraria. Acacia senagal, Capparis decidua, Salvadora oleoides, Asparagus racemosus, Ephedra foliata.
The present population of the world is about
Human population in world is estimated to have crossed 6 billion in the year 1999.
What is the most important factor for the success of animal population?
Natality refers to the rate at which new individuals are born. Adaptability refers to the capacity of the organisms to adapt themselves to their environment.
Keystone species in an ecosystem are those
The keystone species in an ecosystem are those who are the main contributors to the ecosystem.
In increasing order of organizational complexity, which one of the following is the correct sequence?
Population is an aggregation or grouping of individuals of the same species at the same time in a particular area. Species is a grouping of individuals of one or more populations resembling each other in important morphological, anatomical and biochemical characters and can potentially interbreed. Biotic community is an assemblage of interdependent, and ecosystem is a self sufficient and self regulating segment of nature comprising of a biotic community and its physical environment, both interacting and exchanging materials. The basic level of ecological organisation starts with the individual, the next more complex levels are populations, species, community and then ecosystem.
The nature of climax community ultimately depends on
In ecological succession, climax community is a stable, self perpetuating biotic community developing towards the end of biotic succession in an area and is in harmony with the climate of the region.
Human population growth in India
Human population growth in India can be regulated by following the national programme of family planning.
In India, human population is heavily weighed towards the younger age groups as a result of
In India, there is short life span of individuals and high birth rate as compared to other countries. That is why, the human population is heavily weighed towards the younger age groups.
The concept that population tends to increase geometrically while food supply increases arithmetically was put forward by
Thomas R. Malthus put forward a theory of human population growth in 1778. He told that population grows in geometrical progression, whereas the means which support it, grow only in arithmetical progression.
Which of the following pairs is correctly matched?
The correctly matched pair is streamlined body for aquatic adaptation.
Parasitism-inter specific relationship in which one species (parasite) benefits for growth and reproduction and ollic species (host) harmed. Parasite live on or inside the body of host.
Sunken stomata is the characteristic feature of
Sunken stomata is the characteristic feature of xerophytes which help in reducing loss of water from leaf surface. These type of stomata are found in Oleander or Pine.
Tropical forests occur in India
Kerala & Assam. Tropical forests-are highly productive terrestrial ecosystem. Their environment conditions are not climate and wel moisture which causes for their higher productivity.
In a food chain, the largest population is that of
Producers. Number of individuals decreases at successive trophic levels.
Animals that can tolerate a narrow range of salinity are
Stenohaline : Steno meaning narrow and haline meaning salt. A fish cannot handle a wide fluctuation in salt content in water. Many fresh water fish tend to be stenohaline and die in environments of high salinity such as the ocean. Fish living in coastal estuaries and tide pools are often euryhaline (tolerant to changes in salinity) as are many species which have life cycle requiring tolerance to both fresh water and sea water environments such as Salmon.
Xeric environment is characterised by
Xeric environment is characterised by low atmospheric humidity.
Xeric environment is the environment of moisture deficiency. It is found in the desert. It is characterized by the less annual precipitation, low rate of vaporization, low atmospheric humidity and low temperature at night and high during the daytime.
Association of animals when both partners are benefitted
Mutualism type of interactions are shown in plant roots in mycorrhizal region.
Soil best suited for plant growth is
Loam soil is best suited for plant growth because it possesses good aeration, nutritive salts and good water retaining capacity.
The sum total of the populations of the same kind of organisms constitute
A species is a group of individuals of same kind of phenotypic characters and can interbreed easily.
Soil particles determine its
Soil particles size defines its texture. The mineral particles present in soil, vary enosmously in size the fire fiagments. (consisting of sand, silt and clay particles) and coarse fiagments (gravel, copples and stones). The relative proportion's of sand, silt and clay in a soil is referred as soil texture. Fine textured soil have more of clay particles.
Water holding capacity-Larger soil particles like sand, gravel have large pores. This have high less holding capacity and higher percolotion rate field capacity is the of soil moisture or water content held in soil after excess water has drained away.
A fertile agricultural soil appears deep coloured at the surface as compared to soil one metre down. The reason for colour of top soil is
High organic matter darkens the colour of soil. This is soil.
Which one is true?
When the interaction is useful for both the populations.
Deep black soil is productive due to high proportion of
Deep black soil has high content of clay and humus, which makes it more fertile and so productive. Humus is amorphous and colloidal mixture of complex organic substances. It provides fertility to the soil.
Homeostasis is the property of an open system, especially living organisms, to regulate its internal environment to maintain a stable, constant condition, by means of multiple dynamic equilibrium adjustments, controlled by interrelated regulation mechanisms.
Competition for light, nutrients and space is most severe between
Competition is most severe between the members of a population belonging to same niches.
A mutually beneficial association necessary for survival of both partners is
Symbiosis or mutualism is a mutually beneficial association necessary for the survival of both the partners.