Every year 'World Environment Day' is celebrated on 5th of June by 'United Nations Environment Programme'. 

Environment is defined as a natural ecosystem that includes everything around the biotic factors. These are nonbiotic factors. These includes air, water, sunlight. Decomposers are the biotic factors of an ecosystem.

2 species that are coexisting in a particular area have few characteristic features to avoid intraspecific competition.

• The biotic components of the ecosystem are the producers and consumers. The abiotic or the non-living components include soil, water, light, inorganic substances.
• Both biotic and abiotic factors are interdependent in an ecosystem, and if one factor is changed or removed, it can affect the entire ecosystem. Abiotic factors are especially important because they directly affect how organisms survive.
  
• Examples showing the interdependency of biotic and abiotic factors include Frigid climates do not support lizards and other cold-blooded animals, Relation between water and life and the need for sunlight for the process of photosynthesis.
• So, the correct answer is 'All the above'.

• Abiotic factors are non-living chemical and physical parts of the environment that affect living organisms and the functioning of ecosystems. For example, rain, wind, temperature, altitude, soil, pollution, nutrients, pH, types of soil, and sunlight.
• The edaphic factor is an abiotic factor relating to the physical or chemical composition of the soil found in a particular area. For example, the pH of the soil, Minerals present in the soil and organic matter in the soil.
  
• Hence pH, Minerals and organic matter in soil are examples for Edaphic factors because these are physical or chemical composition of the soil found in a particular area. 
• So, the correct answer is 'All the above'.

Our habitat includes both biotic components like micro-organisms, plants, animal etc and also abiotic components like soil, water, atmosphere etc

Photosphere is the lowest layer around the sun in which the energy of the sun is emitted as light. Due to this the layer appears bright. It is approximately 400 km in thickness. So, the correct option is 'Photosphere'.

The ionosphere is defined as the layer of the Earth's atmosphere that is ionized by solar and cosmic radiation. It lies 75 to 1000 km above the Earth. It is distinguished because it is ionized by solar radiation. It plays an important part in atmospheric electricity and forms the inner edge of the magnetosphere. It has practical importance because, among other functions, it influences radio propagation to distant places on the Earth. It is also called as thermosphere.

The troposphere is the lowest layer of Earth's atmosphere and site of all weather on Earth. The troposphere is bonded on the top by a layer of air called as the tropopause, which separates the troposphere from the stratosphere, and on bottom by the surface of the Earth. It contains approximately 75% of the atmosphere's mass and 99% of its water vapour and aerosols. The average depth of the troposphere is approximately 17 km in the middle latitudes.

Environmental monitoring describes the processes and activities that need to take place to characterize and monitor the quality of the environment. It can be defined as the systematic sampling of air, water, soil and biota in order to observe and study the environment. 

Atmospheric layers include the troposphere (0 to 16 km), stratosphere (16 to 50 km), mesosphere (50 to 80km) and thermosphere (80 to 640km). In the troposphere and mesosphere, temperature generally falls with increasing altitude, while in the stratosphere and thermosphere, temperature rises with increasing altitude. In addition to temperature, other criteria can be used to define different layers in the atmosphere. 

Exosphere is the outer fringe of Earth's atmosphere, which extends some 20000 miles from the planet. It's dominant element is hydrogen and its temperature ranges from $200^0 F$ to $1000^0 F$. The lower part of exosphere contains abundance of helium besides hydrogen and is called as “helium zone”. Hence, option D is correct.

Colour of the praying mantis varies from brown to green, depending on its habitat. Colour of the body provides camouflage and enables praying mantis to blend with its environment and become invisible for both the predators and the prey.

Natural flora and fauna are the plants and animals that live in that particular area. The harmful effect of pollution such as air or water is most marked on these organisms as they are the ones who at the risk of initial exposure due to their proximity to pollutants. Thus the correct answer is option A.

5th June is World Environment Day, 22nd April is World Earth Day, 3rd September is World Ozone Day and 3rd December is World Conservation Day.

5th June every year is observed as World Environment Day. This is to ensure awareness among people for the conservation and enhancement of the environment that forms a very integral part of our ecosystem.

The United Nations (UN) International Day for the Preservation of the Ozone Layer is celebrated on September 16 every year. This event commemorates the date of the signing of the Montreal Protocol on Substances that Deplete the Ozone Layer in 1987.

Clay is rich in minerals but has poor aeration and sand has good aeration but lacks water holding capacity. The size of soil particles is largest in the case of sand and smallest in the case of clay. Loam is an ideal mix of clay and sand and it contains humus.

Niche refers to the totality of an organism’s adaptations, its mode of use of available resources, and the lifestyle in its community. It includes the mode of consumption of materials in its environment as well as its interactions with other organisms. Habitat portion of earthworm's fundamental niche refers to the soil while its role as decomposer is the realized niche. Thus, the correct answer is A.

Xeric environment means dry conditions or low atmospheric humidity and lack of precipitation. Also the temperature variations depend on several other variables like altitude, latitude and hemisphere. High rates of vapourisation is not a characteristic of environment but a consequence of low atmospheric humidity.

Biotic potential is the maximum capacity of a population to reproduce under ideal conditions (environmental).

The edge effect is an ecological concept that describes how there is a greater diversity of life in the region where the edges two adjacent ecosystems overlap, such as land/water, or forest/grassland.

An organisms niche and not the habitat describes its location, requirements and work within a particular community or ecosystem. If two species occupy the same niche they will generally compete with one another until one is displaced.

A pheromone is a secreted or excreted chemical factor that triggers a social response in members of the same species meant for communication and coordination. Pheromones are chemicals capable of acting outside the body of the secreting individual to impact the behavior of the receiving individual.

Ecological equivalents are the organisms that occupy same niche iin different habitats (or geographical areas) e.g. both one and cat feed on shews and mice, they occupy the same niche through their habitats are different. 

Tundras are among Earth's coldest, harshest biomes. Tundra ecosystems are treeless regions found in the Arctic and on the tops of mountains, where the climate is cold and windy and rainfall is scant. So, the correct option is "Tundra region".

The revolution of our planet around the Sun and the tilt of axis cause annual variations in the intensity and duration of temperature, resulting in distinct seasons. These variations together with annual variation in precipitation account for the formation of major biomes such as desert, rain forest, and tundra. 

Every organism has its own ecosystem where it can survive but need to adapt to changes of habitat for survival.

Bobcat is originated from North America whereas Wombat, Bandicoot, Spotted cuscus.

Group of same species in a given area is called population and interaction of population with environment is called Autoecology. So the correct option is " Autoecology"

According to the competitive exclusion principle, no two species can occupy exactly the same niche in exactly the same habitat at exactly the same time. Two species whose niches overlap may evolve by natural selection to have more distinct niches, resulting in resource partitioning.

Inside a cell, numerous organelles function to remove wastes. The lysosome is the organelle involved in digestion and waste removal because they contain digestive enzymes which are not present in the secretion of the parotid.

The Environment (Protection) Act 1986 came into force soon after the Bhopal Gas tragedy. Thereafter, which a large number of laws came into existence as the problems began arising.

A salt-rich habitat is the type of habitat which has plenty of minerals and salts in it. Salt marshes are coastal wetlands that are flooded and drained by salt water brought in by the tides. Saline soils are the ones that have the input of salt water in it. Coastal dunes are immediate landward of the beach are commonly found large, linear accumulations of sand known as dunes. 

Environmental resistance factors are all the things that keep a population of organisms from endlessly increasing. They lower the chances for reproduction, affect the health of organisms, and raise the death rate in the population. Environmental resistance factors include factors that are biotic (living) and abiotic (non-living). Biotic factors are things like predation, parasitism, lack of food, competition with other organisms and disease. Abiotic factors include drought, fire, temperature, and even the wrong amount of sunshine. 

(i) At depth, the first colour to get absorbed is red then red and then yellow. Even water at 5Ft depth gets a noticeable loss of red.

Desert lizards manage to keep their body temperature constant by behavioral means. They bask in sun and absorb heat when their body temperature drops but move into shades when ambient temperature starts increasing. So the correct option is " i,iii"