The zone of atmosphere in which the ozone layer is present is called:
(c) The ozone (O3 ) found in upper part of the atmosphere, i.e., Stratosphere, is Good ozone, since, it acts as a shield for absorbing UV-radiations from sun.
Just as a person moving from Delhi to Shimla to escape the heat for the duration of hot summer, thousands of migratory birds from Siberia and other extremely cold northern regions move to:
(d) The Keoladeo National Park is a famous avifauna sanctuary in India that plays host to thousands of birds especially during the summer season. It is formerly known as the Bharatpur Bird Sanctuary in Bharatpur, Rajasthan. October to February is the best time, for the migratory birds are there as well as the residents. In August local birds start their nest building and rear their young for the next few months. October/November is when the migrants arrive. Most stay till March including the Siberian Crane
Given below is a simplified model of phosphorus cycling in a terrestrial ecosystem with four blanks (A-D). Identify the blanks:-
(c) Phosphorus is an important element for living beings. Consumers obtain phosphorus directly or indirectly from plants. Phosphorus is also present in phosphatic rocks. It is released during the decomposition of plant and animal remains. The released phosphorus may reach the deeper layers of soil and gets deposited as phosphate rocks. All plants and animals eventually die and in due time, their organic remains or debris decay through the action of micro-organism and the phosphates are released into the water for recycling.
If 20 J of energy is trapped at producer level, then how much energy will be available to peacock as food in the following chain? plant → mice → snake → peacock:
(a) According to 10 percent law, during the transfer of energy from organic food from one trophic level to the next, only about ten percent of energy from organic matter is stored as flesh. The remaining is lost during transfer, broken down in respiration, or lost to incomplete digestion by higher trophic levels. If 20 J of energy is trapped at producer level, then 0.02 J of energy will be available to peacock as food in the given food chain.
Most animals are tree dwellers in a:
(c) In tropical rain forest zone, most of the animals prefer to live on trees. The reason is that the floor of forest is full of humidity, decomposing leaves and other organic matters and is the habitat of insects etc.
A population will not exist in Hardy - Weinberg equilibrium if :
(d) The theory of Hardy- Weinberg equilibrium states that in the absence of disturbance on the level of genetic structure, a population’s existance will not continue. Thus mating should be in a random way
Most animals that live in deep oceanic waters are:
(c) Most animals that live in deep oceanic waters and called benthos are scavengers or detritivores. Detritivores are the organisms which feed on dead plants and animal residues.
In which of the following interactions both partners are adversely affected ?
(d) Competition occurs for light, food and space among organisms in which all partners are adversely affected in an ecosystom.
Gause's principle of competitive exclusion states that :
(c) Gause's principle of competitive exclusion can be restated to say that no two species can occupy the same niche indefinitely when resources are limiting. Certainly species can and do coexist while competing for some of the same resources. Nevertheless, Gause's theory predicts that when two species coexist on a long-term basis, either resources must not be limited or their niches will always differ in one or more features; otherwise, one species will outcompete the other and the extinction of the second species will inevitably result, a process referred to as competitive exclusion
When does the growth rate of a population following the logistic model equal zero ? The logistic model is given as dN/dt = rN(1–N/K)