Question bank

Q1) Write the meaning and definition of an Environment.  (5)

A1) Meaning

The term environment comes from the French word "environment" which means to surround. This refers to both abiotic (physical or abiotic) and biological (living) environments. The word environment means the environment in which living things live. The environment and living things are two dynamic and complex elements of nature. The environment regulates the life of living things, including humans. Humans interact with the environment more actively than other living things. The environment usually refers to the substances and forces that surround living things.

The environment is the sum of the conditions that surround us at a particular point in time and in space. It consists of an interacting system of physical, biological and cultural elements, which are interrelated collectively and individually. The environment is the sum of the conditions under which an organism must survive or sustain its life process. It affects the growth and development of living things.

In other words, the environment is that surrounds living things from all sides and affects their lives. It consists of the biosphere, hydrosphere, lithosphere, and atmosphere. Its main components are soil, water, air, living things and solar energy. It has provided us with all the resources to live a comfortable life.

Definition:

1. According to P. Gisbert “Environment is anything immediately surrounding an object and exerting a direct influence on it.”

2. According to E. J. Ross “Environment is an external force which influences us.”

3. According to Bowling, "a person's environment consists of the sum of the stimuli he receives from his conception to his death." The environment is physically, intellectually, mentally, economically, politically, Indicates that it contains various types of power, cultural or social, moral and emotional.

4. Douglas and Holland define that "the term environment is used to collectively describe all external forces, influences and conditions that affect life, nature, behavior and the growth, development and maturity of living things."

Therefore, an environment is anything that directly surrounds an object and directly affects it. Our environment is different from us, but refers to things or institutions that affect our lives and activities. An environment in which humans are surrounded and affected by factors such as nature, man-made, society, biology, and psychology.

Q2) Say something about scope of environment. (5)

A2) Scope of environment:

The environment consists of four segments of the Earth: the atmosphere, the hydrosphere, the lithosphere, and the biosphere.

1. Atmosphere: The atmosphere forms a unique protective layer around the earth with a thickness of about 100 km. A surface of gas called the atmosphere surrounds the earth and protects the surface of the earth from the harmful ultraviolet rays of the sun. It sustains life on earth. It also regulates the temperature to prevent the earth from getting too hot or too cold. It saves it from the hostile environment of space . In addition to nitrogen and oxygen, the atmosphere is composed of argon, carbon dioxide, and trace gases.

The atmosphere has a significant effect on the energy balance of the Earth's surface. It absorbs most of the cosmic rays from space and most of the electromagnetic radiation from the sun. It transmits only ultraviolet, visible, near-infrared radiation (300-2500 nm) and radio waves. (0.14-40 m) Filters out super-violating waves that damage tissues below approximately 300 nm.

2. Hydrosphere: The hydrosphere is made up of all types of water resources, including oceans, seas, lakes, rivers, streams, reservoirs, polar caps, glaciers, and groundwater. The ocean accounts for 97% of the Earth's water, and about 2% of its water resources are confined to polar ice caps and glaciers. Only about 1% of freshwater is available as surface water for rivers, lakes, streams, and groundwater for human use.

3. Lithosphere: The lithosphere is the outer mantle of the Solid Earth. It is composed of minerals present in the crust and soil. Minerals, organic matter, air, water.

4. Biosphere: The biosphere describes the interaction of living territories with their environment: the atmosphere, the hydrosphere, and the lithosphere.

The scope of environmental research is very wide, and many fields such as

i)    conservation of natural resources

Ii)  ecological aspects

Iii)    pollution of surrounding natural resources

Iv)     pollution management

v)  related social issues.

Vi)     We are dealing with the impact of the human population on the environment.

Q3) Explain in the components of environment.With diagram.   (8)

A3) Components of environment:

The environment is made up of interacting systems of physical, biological and social elements that are interrelated individually or collectively in various ways. These elements are:

(1) Physical elements

Physical elements are space, terrain, body of water, climate, soil, rocks and minerals. They determine the diverse nature, opportunities, and limits of human habitat. This physical constituent of the environment is again divided into three parts.

These are:

(i) Atmosphere (gas)

(ii) Hydrosphere (liquid)

(iii) Lithosphere (solid)

These three parts represent the three important states of the substances that make up the environment. This physical component of the environment consists entirely of non-living organisms such as air, water and soil. All these non-living organisms have a great impact on all living things, including humans. Water and temperature are the most important abiotic factors that affect living organisms. A larger proportion of body weight is due to water.

All living things need water to survive. In addition to water, it is a major important liquid for maintaining the optimum temperature of the body. All life activates work in a specific temperature range. Creatures die when the temperature rises higher than necessary.

Air is the main physical component that oxygenates breathing. All living things, including plants and animals, need oxygen to survive. Oxygen is taken into the body by breathing and excreted from carbon dioxide. On the other hand, plants take in carbon dioxide during photosynthesis to cook and supply oxygen to the surroundings.

Soil is of paramount importance for all living things to create habitats. It is the soil on which plants grow and build homes for humans. Groundwater present in the soil provides drinking water and other agricultural activities.

(2) Biological elements

Biological elements such as plants, animals, microorganisms, and men make up the biosphere. The self sufficient large ecosystem of the earth is called Biosphere. All ecosystems consist of three different types of living organisms.

These three types are named as:

(a)    Producers,

(b)   Consumers,

(c)    Decomposers.

Producers are usually green plants and other photosynthetic bacteria that produce a variety of organic substances such as carbohydrates and proteins with the help of water, soil and light energy. Consumers rely on organic foods produced by green plants for nutrition. Decomposers cause the decomposition of dead plants and animals and return the various minerals needed to carry out the biogeochemical cycle. These zones are explained in fig 1(A).1

(3) The social components of the environment are mainly composed of different groups of different organisms such as birds and animals. Humans are the most intelligent creatures. Like other creatures, humans build houses, prepare food, and release waste into the environment. As the Greek philosopher Aristotle said, humans are social animals. He makes various laws and policies for the proper functioning of society.

His three components of the environment create four important zones. These are the atmosphere, the hydrosphere, the lithosphere, and the biosphere. These he has a continuous interaction between the four zones. These interactions include the transport of various elements, compounds, and energy forms.

Q4) Explain the social components of environment.     (8)

A4) The social components of environment are :

Atmosphere:

The Earth's atmosphere, a complex fluid system of gas and suspended particles, did not have its origin at the beginning of the planet. Today's atmosphere derives from the Earth itself through chemical and biochemical reactions. The fluid system forms an envelope of gas around the earth, but its boundaries are not easy to define. They can be arbitrarily defined as the Earth's atmospheric interface and the cosmic interface.

A gas like nitrogen. Oxygen, argon, carbon dioxide, water vapor, etc. combine to form the total volume of the atmosphere. With suspended particles, ie. Dust and so in so make up gas turbidity, especially in the troposphere. However, the composition and structure of the atmosphere also change over time and space.

The vertical structure of the atmosphere is closely related to the absorption of radiant energy, which can be explained by changes in temperature [Fig. 1 (A) 2]. Less than 60 kg. There are two main absorption zones on the surface of the earth and the ozone layer. The absorbed energy is redistributed by radiation, conduction and convection.

Therefore, there are two maximum temperatures, one on the surface of the earth and one at an altitude of 50 km. Above each of these maximums is primarily convective mixing. The temperature of these mixed layers decreases with height above the heat source. The lower part of these two zones is called the troposphere, and the upper part is called the mesosphere.

These are separated by a less mixed layer, where the atmosphere tends toward a layered structure called the stratosphere. There is a tropopause between the ionosphere and the stratosphere, which indicates an approximate upper limit for the mixing of the lower atmosphere. The average height of this is usually 11 km, but this is different on Earth.

At tropical latitudes, its average height is 16 km. It is only 10 km in polar latitudes. Above the mesosphere is one heating zone over 90 km. From the surface where short-wave UV light is absorbed by many oxygen molecules present at this height. This is called the thermosphere.

Within this layer, ionization occurs that produces charged ions and free electrons. At a height of about 700 km beyond the thermosphere is the exosphere, where the density of the atmosphere is very low. At this level, the number of ionized particles concentrated in a band called the Van Allen belt is increasing.

However, this easy model of vertical structure are often simplified to supply a model of the atmosphere as two concentric shells, the boundary of which is defined by the stratopause, which is approximately 50 km. Above the surface of the earth and a virtual out-of-atmosphere limit of about 80,000 km.

Below the stratopause, in the stratosphere and troposphere, there is 99% of the total mass of the atmosphere, and it is at this level that the atmospheric circulation system works. Beyond the stratopause, there is a layer of approximately 80,000 km. The thick layer contains only 1% of the total mass of the atmosphere and is ionized by high-energy, short-wavelength solar radiation. The temperature distribution of the atmospheric layer is shown in Fig. 1 (A) 2.

Hydrosphere:

This includes surface water and its surrounding interfaces. It is indispensable for the survival of life molecules. Water has many physical and chemical properties that help molecules function as the optimal medium for vital activity. The movement of water from the surface to the atmosphere by the water cycle seems to be a close system.

Water is that the most abundant substance on the surface of the world . The ocean covers about 71% of the Earth's water, and glaciers and ice caps cover even more. Water is also present in lakes and streams, soil and underground reservoirs, in the atmosphere, and in the body of all living things. Thus, all forms of water, such as ice, liquids, water and water vapor, are very familiar to us.

We use water for home, industry, agriculture and recreation. The quantity and quality of water required for these applications varies greatly. Use all available water sources in some way, including inland water, groundwater, and even ocean water.

The available pure freshwater has declined significantly, but the demand for water resources around the world is increasing day by day. Therefore, it is necessary to make valuable use of pure fresh water and its fruitful storage and preservation. The outline of the water cycle is shown in Fig. 1 (A).

Lithosphere:

It is the outer boundary layer of the Solid Earth, a discontinuity in the mantle. The outer boundaries form a complex interface with the atmosphere and hydrosphere, and are also the environment in which life has evolved. The inner boundary is adjacent to the rock, which is near its melting point and can move relative to the upper lithosphere.

Basically, the lithosphere is nothing more than a crustal system consisting of various layers: the core, the mantle, and the outer shell. Such a crustal layer is composed of various elements mixed in various proportions. In general, earth caste is composed of three major classes of rock (classified based on the mode of origin).

Igneous rocks, sedimentary rocks, metamorphic rocks. There are two types of crust. The continental crust is composed of silicon-aluminum granite with an average density of 2.8. The other oceanic crust is basaltic in composition and consists of more basic minerals with an average density of 3.0. Overall, the average density of the Earth is 5.5 gm / c.c.

Interactions between the lithosphere's crust, atmosphere and biosphere occur where the continental crust is exposed above sea level. At the land-air interface, crustal material is exposed to solar radiation energy, precipitation, and atmospheric gas inputs. These inputs are often modified or function by the influence of the biosphere's biological system. Under the influence of these inputs, crustal rocks are decomposed by the weathering process and moved to a fine porous crustal layer called soil.

The outline of the stratum and the composition of the crustal material are shown in Fig. 1 (A) 4.

Biosphere:

The biosphere covers all zones on the earth where life exists, that is, the entire biological resources of the earth. It has evolved from 4.5 billion years on Earth. There are many types of life, from the upper part of the lithosphere, to the entire hydrosphere, to the lower atmosphere. These biological resources and their surroundings make up the "biosphere" in which human beings act as the most evolved organisms.

The steps involved in the origin of life on Earth are extremely complex and take centuries. Considerable uncertainty surrounds the details of atmospheric composition, the processes involved, and even the sequence of several events that lead to the formation of living cells. Traditionally, the earliest organisms in plants were considered heterotrophic prokaryotes. After that, autotrophic prokaryotes and eukaryotes begin to appear as gradual evolutionary changes. The major steps in the origin of life on the Primitive Earth are shown in Figure 1 (A) .5.

Life on Earth requires water, an energy source (sunlight), and a variety of nutrients found in soil, water, and air. The right combination of these necessities cannot be found in the upper atmosphere or deep underground. These are only present in a narrow layer near the surface of the Earth.

This biosphere layer extends to most surfaces of the Earth. This includes the upper layers of the Earth's crust and the thick soil layers that support plant life. This living area also covers about 8 km. It reaches the atmosphere (biota in the air) and extends up to 8 km. To the bottom of the sea. Organisms are not uniformly distributed on Earth, with few organisms inhabiting polar ice caps and glaciers, but many inhabiting rainforests (Fig. 1 (A)). ). 6).

Within the living area, there are several major areas, including certain types of ecosystems. These major areas are called biomes. Biomes are recognized by major ecosystem types such as rainforests, temperate forests, prairie, deserts, and Arctic tundra. Ecosystems are also made up of populations of individuals.

Tables 1 (A) .1 and 1 (A) .2 show global estimates of both prokaryotic and eukaryotic species. 2 These numbers are ours on Earth. Does it imply the fact that the biological world is so diverse?

Q5) What is lithosphere?    (7)

A5) Lithosphere:

It is the outer boundary layer of the Solid Earth, a discontinuity in the mantle. The outer boundaries form a complex interface with the atmosphere and hydrosphere, and are also the environment in which life has evolved. The inner boundary is adjacent to the rock, which is near its melting point and can move relative to the upper lithosphere.

Basically, the lithosphere is nothing more than a crustal system consisting of various layers: the core, the mantle, and the outer shell. Such a crustal layer is composed of various elements mixed in various proportions. In general, earth caste is composed of three major classes of rock (classified based on the mode of origin).

Igneous rocks, sedimentary rocks, metamorphic rocks. There are two types of crust. The continental crust is composed of silicon-aluminum granite with an average density of 2.8. The other oceanic crust is basaltic in composition and consists of more basic minerals with an average density of 3.0. Overall, the average density of the Earth is 5.5 gm / c.c.

Interactions between the lithosphere's crust, atmosphere and biosphere occur where the continental crust is exposed above sea level. At the land-air interface, crustal material is exposed to solar radiation energy, precipitation, and atmospheric gas inputs. These inputs are often modified or function by the influence of the biosphere's biological system. Under the influence of these inputs, crustal rocks are decomposed by the weathering process and moved to a fine porous crustal layer called soil.

The outline of the stratum and the composition of the crustal material are shown in Fig. 1 (A) 4.

Q6) Define ecosystem. (7)

A6) The term ecosystem was coined in 1935 by Oxford ecologist Arthur Tansley and embraces the interaction between the biological and abiotic elements of the environment at a particular location. The living and non-living elements of an ecosystem are known as biological and abiotic components, respectively.

Ecosystems, in the form currently accepted by Eugene Odum, are "all living things, that is, specific nutritional structures in which the flow of energy interacts with the physical environment to lead to well-defined nutritional structures, biodiversity. Defined as "a unit that contains the local community." And the material cycle, the exchange of matter between living and non-living things in the system. "

Definition of an Ecosystem

An ecosystem or biome represents a single environment and all living (living) organisms and non-living (non-living) factors contained within or characterizing it. Ecosystems embody every aspect of a single habitat, including all interactions between its different elements.

(1) The ecosystem may be a major structural and functional unit of ecology.

(2) The structure of an ecosystem is linked to the diversity of its species; the most complex ecosystems have a great diversity of species.

(3) The function of the ecosystem is related to the flow of energy and the cycle of materials through and within the system.

(4) The relative amount of energy needed to take care of an ecosystem depends on its structure. The more complex the structure, the less energy it needs to maintain itself.

(5) Ecosystems mature from less complex to more complex states. The early stages of such a succession have an excess of potential energy and a relatively high energy flow per unit of biomass. The later (mature) stages have less energy accumulation and its flow through more diverse components.

(6) Both the environment and therefore the fixation of energy during a given ecosystem are limited and can't be exceeded without causing serious undesirable effects.

(7) Environmental alterations represent selective pressures on the population to which it must adapt. Organisms that are unable to adapt to the changed environment must need to disappear.

The ecosystem is an integrated unit or area of varying size, comprising vegetation, fauna, microbes and the environment. Most ecosystems characteristically have well-defined soil, climate, flora and fauna (or communities) and have their own potential for adaptation, change and tolerance.

Q7) What are the components of an ecosystem?  (5)

A7) Components of Ecosystem:

The ecosystem has two main components that are in constant communication with each other.

Ecosystem biological components

The living components of an ecosystem are called biological components. Some of these factors include plants, animals, fungi and bacteria. These biological components can be further categorized based on energy requirement sources. Producers, consumers and decomposers are in three broad categories of biological components.

Producers are plants of the ecosystem and can generate their own energy requirements through photosynthesis in the presence of sunlight and chlorophyll. All other organisms depend on plants for their food and oxygen energy requirements.

Consumers include herbivores, carnivores and omnivores. Herbivores are plant-eating organisms. Carnivores feed on other organisms. Omnivore animals are animals that can eat both plant and animal tissues.

Decomposers are fungi and bacteria that are saprophytic plants. They eat rotting organic matter and convert it to nitrogen and carbon dioxide. Mycotrophs play an important role in recycling nutrients so that growers, or plants, can use them again.

Abiotic components of the ecosystem

Abiotic components are physical and / or chemical factors that act on living organisms in all parts of life. These are also called ecological factors. Chemical and physical factors are characteristic of the environment. Light, air, soil, nutrients, etc. form the abiotic elements of the ecosystem.

Abiotic factors vary by ecosystem. In aquatic ecosystems, abiotic factors include water pH, sunlight, turbidity, water depth, salt content, available nutrients, and dissolved oxygen. Similarly, abiotic components of terrestrial ecosystems include soil, soil type, temperature, rain, altitude, wind, nutrients, and sunlight.

Here, the sun is the energy source. Producers / plants use this energy to synthesize food within the presence of CO2 and chlorophyll. The energy from the sun goes through several chemical reactions and is converted into chemical energy.

Q8) Write the features of ecosystem.   (8)

A8) Characteristics of an Ecosystem:

The elements considered to be lifeless in an ecosystem also are referred to as "abiota", but also interact with one another and with other components.

Among the abiotic components are physical factors like humidity, light, temperature, wind, dew, and space.

b.  Biotic components of an ecosystem

Organisms that sleep in an ecosystem also are referred to as “biota”. Biotic components are often classified consistent with the sort of food which characterizes them or consistent with their nutritional needs, into autotrophs and heterotrophs.

Autotrophs are self-fertilizing or feeding organisms. It's bacteria, plants and algae that use inorganic raw materials to form their own food.

In contrast, heterotrophs are those that prey on others. With this we ask the animals, fungi and microorganisms which, from the ingestion of other animals or plants, get their energy and nutrients.

c.  How an ecosystem works

Basically, for an ecosystem to function, you would like energy. Energy is what sustains the lifetime of the ecosystem. The most source of energy for any ecosystem comes from the sun.

Another function of energy in an ecosystem is that the mobilization of water, minerals and other physical elements, which allows them to pass from soil, water or air to organisms.

Even the energy allows these components to pass from one living organism to a different and eventually return to the soil, water or air from which they came out, thus closing the cycle.

d.  Ecological succession

Sometimes certain elements of an ecosystem are naturally replaced by another element over time.

For example, within the case of vegetation where grass replaces mosses and lichens. Once the ecosystem regains its balance and therefore the changes cease, it's called the climax.

From there, the changes that occur are among an equivalent things, for instance , new trees replacing old trees.

When changes occur as a result of human intervention, succession is claimed to possess anthropogenic causes.

e.  Biomes

Biome refers to large terrestrial ecosystems that are characterized by an equivalent sort of vegetation.

On our planet, there are many biomes which are mainly determined by climate (temperature and rain), soils and vegetation.

The climate is successively influenced by the macroclimate of the region and therefore the microclimate of the precise place.

f.    Classification consistent with their origin

Ecosystems are often classified in several ways. a primary classification is consistent with whether the origin of an equivalent thing is natural or artificial.

Natural ecosystems haven't been altered by act . Artificial ecosystems are created by humans for a selected purpose. Samples of the latter are dams or reservoirs.

g.  Sort by size and site

They can even be classified consistent with the dimensions of the ecosystem. It’s called Micro ecosystem when it's a little extension, like an aquarium or a little garden on the balcony of a house.

On the opposite hand, we speak of macro ecosystem when it involves ecosystems of great extension like for instance the ocean or a mountain.

It also can be classified consistent with the situation of the ecosystem. When it's within the water, it's called the aquatic ecosystem.

When are  they ecosystems that also combine relationships within the earth are called air-terrestrial.

While the so-called transitional ecosystems are people who occur between water and land, like the banks of rivers or swamps.

Food chains

In an ecosystem, living things share the search for food to survive. Within the case of animals, the competition for food is combined with the necessity to not be devoured during this attempt.

In the case of plants, the necessity for food is given by water, natural light, air and minerals present within the soil. Either way, living things need the energy that provides them food.

The way during which energy passes from one animate thing to a different is named the "food chain". Generally, it goes like this: the sun's energy is absorbed by the plants.

Herbivores - animals that eat plants - get a number of this energy from the ingestion of plants. And within the higher levels of the chain, that is, for the carnivores, the energy that comes in is even better.

Q9) Explain the types of ecosystem. (8)

A9) Types of Ecosystem:

An ecosystem is a self-contained unit of living things and their non-living environment. The following chart shows the types of Natural Ecosystem −

Land ecosystems, sometimes referred to as biomes, are found on different continents of the globe and can be defined in different ways. There are many types, but they can all be divided into four main types.

Forest

Forest ecosystems range from arid tropical forests, rainforests, temperate forests, and northern forests (including taiga and coniferous ecosystems). These forests are defined by the climate they face.

Temperate forests are found in areas that experience seasonal changes from winter to summer. These forests are usually made up of trees that lose their leaves in the colder months and regain their leaves in the warmer months. These forest trees are also conifers that do not shed leaves, or a combination of the two.

Tropical forests are commonly found in warm and humid areas. Trees in these areas are generally tall and full of leaves. These forests are dense because their roots are spread throughout the soil.

Northern forests are found in areas with low temperatures. They usually experience short summers and long winters, and temperatures remain low. The trees found in these areas are usually evergreen-like conifers because they are good at coping with the cold.

Desert

Famous for its dunes and high temperatures, deserts are usually defined as areas with annual rainfall of less than 25 cm (10 inches). Water shortages are a major factor in determining whether an area will become a desert. The desert is also known for its windiness.

Temperature is not a major factor in deserts and can be found in cold and hot environments around the world. Limited water can come from rain, snow, or other means of precipitation. Places like the Sahara Desert are often hot, but places like the Gobi Desert can face extremely low temperatures during the winter months.

Given the harshness of the desert, it is easy to think that life cannot thrive there. However, many flora and fauna that have adapted to harsh life can be found above and below the deserts of the world.

Meadow

Grassland ecosystems include prairie, grassland, and savanna. Grasslands are distributed in temperate and tropical regions of the world. Like deserts, grasslands are primarily defined by the amount of water available. Grasslands typically have about 10 to 30 inches of rainfall each year. This means that it can also live in cold regions such as Siberian grasslands.

Grasslands are famous for the large amount of grass that covers the area, ranging from 60 to 90%. Few trees are spread throughout the ecosystem. In many grasslands, fire helps prevent trees from overtaking the area. The meadows are dotted with flowering plants.

These ecosystems are known for grazing and grazing animals that use them as food. These animals provide fertilizer and help stop the growth of more trees grazing throughout the ecosystem.

Tundra

Tundra is a commonly found ecosystem north of northern forests. These areas are known for their cold weather, as they are mostly covered with frozen underground soil and permafrost. They have no trees, their vegetation is short, and they grow only when sufficient topsoil has melted.

Precipitation in the tundra is similar to that in the desert. The organisms that live in this ecosystem are very adaptable to the harsh cold. Includes Reindeer, Snowy Owl,  Goose and more. No reptiles are found in this area.

Tundra found in mountainous areas is commonly referred to as alpine tundra. The creatures that live here generally move because they move in the alpine tundra during warmer months and leave when it gets colder.

b.  Aquatic ecosystem

Aquatic ecosystems represent ecosystems that inhabit the waters of the world. They can be divided into two main categories: marine ecosystems and freshwater ecosystems.

Aquatic ecosystems are shaped by key factors such as the amount of sunlight, water depth, water temperature, salt content, and sediment that different regions receive.

Marine

Marine ecosystems contain high levels of salinity and are composed of many of the world's oceans and other waters. Due to the biodiversity and scale of marine ecosystems, they are the richest ecosystems in the world.

The pelagic marine ecosystem represents the open ocean where marine life freely swims and floats. They are not attached to the bottom or surface. These are like plankton and whales.

Benthos marine ecosystems represent the bottom of the ocean where organisms attach to something or are very close to the bottom. These include coral and mangrove areas, each of which constitutes its own ecosystem.

Fresh water

Freshwater ecosystems are much less salty than marine ecosystems. They are usually represented as lakes, ponds, rivers, and other places where freshwater sources can be found.

Like marine ecosystems, freshwater ecosystems can be divided into two areas: static water, like lakes, and flowing water, like lakes.

In addition to fish, freshwater ecosystems also include insects, amphibians, algae, and other plants that distinguish them from marine ecosystems.

Estuary

The estuary is a special ecosystem because freshwater meets seawater. This ecosystem contains organisms that can survive in this chaotic environment.

Q10) State the structure of ecosystem.  (8)

A10) Ecosystem structure is basically a description of the biological and physical characteristics of the environment, including the amount and distribution of nutrients in a particular habitat. It also provides information on the range of climatic conditions in the area.

From a structural point of view, all ecosystems are made up of the following basic components:

1. Non-biological components:

Ecological relationships manifest themselves in the physicochemical environment. Ecosystem abiotic components include basic inorganic and compounds such as soil, water, oxygen, calcium carbonate, phosphoric acid, and various organic compounds (organic activity or death by-products).

This includes physical factors and factors such as humidity, wind flow and solar radiation. The radiant energy of the sun is the only important source of energy for the ecosystem. The amount of abiotic components such as carbon, phosphorus, and nitrogen present at any given time is known as neglected or retained.

2. Biological components:

Biological components include all living organisms that exist in the environmental system.

From a nutritional point of view, biological components can be divided into two basic components.

(i) Autotrophic ingredients and

(ii) Heterotrophic components.

Autotrophic components include all green plants that fix the radiant energy of the sun and produce food from minerals. Heterotrophs include non-green plants and all animals that feed on autotrophs.

Therefore, the biological components of an ecosystem can be explained under the following three headings:

1. Producer (autotrophic ingredient),

2. Consumers, and

3. Decomposer or reducer and transformer.

The amount of biomass at any point in the ecosystem is known as a standing crop and is usually expressed as free energy in terms of raw weight, dry weight, or calories / meter.

Producers (autotrophs):

Producers are autotrophs, primarily green plants. They use the radiant energy of the sun in a photosynthetic process where carbon dioxide is assimilated and light energy is converted into chemical energy. Chemical energy is actually trapped in energy-rich carbon compounds. Oxygen is generated as a by-product of photosynthesis.

It is used by all living things for breathing. Pond algae and other aquatic plants, field grasses, and forest trees are examples of producers. Purple bacteria and chemosynthetic bacteria that assimilate carbon dioxide with solar energy only in the presence of organic compounds also belong to this category.

In the energy context, the term producer is misleading because producers produce carbohydrates rather than energy. Since they convert or convert radiant energy into chemical forms, E.J. Colmondi proposes a more appropriate alternative term, "transducer" or "transducer". Due to its widespread use, the term producer is still retained.

Consumer:

Living members of ecosystems that consume foods synthesized by producers are called consumers. This category includes all kinds of animals found in ecosystems.

Consumers have different classes or categories, including:

(a) First order consumer or primary consumer,

(b) Secondary or secondary consumer,

(c) Tertiary or tertiary consumers, and

(d) Parasites, scavengers, and scavengers.

(a) Primary consumer:

These are pure herbivores and rely on their producers or green plants for food. Rabbits, rodents, insects, deer, cows, buffalos and goats are some of the common herbivores in terrestrial ecosystems, including small crustaceans and mollusks in aquatic habitats. Elton (1939) named the ecosystem herbivores "core industrial animals." Herbivores serve as the main food source for carnivores.

(b) Secondary consumers:

These are carnivores and omnivores. Carnivores are carnivores, and omnivores are animals adapted to consume herbivores and plants as food. Examples of secondary consumers are sparrows, crows, foxes, wolves, dogs, cats and snakes.

(c) Tertiary consumers:

These are the top carnivores that prey on other carnivores, omnivores and herbivores. Lions, tigers, hawks, vultures, etc. are considered tertiary or top consumers.

(d) In addition to the various classes of consumers, consumers also include parasites, scavengers, and pesticides. Parasitic plants and animals utilize the biological tissues of various plants and animals. Scavengers and scavengers feed on carcasses of plants and animals.

Decomposer and Transformer:

Decomposers and transformers are the living components of the ecosystem, fungi and bacteria. Decomposers attack the carcasses of producers and consumers, breaking down complex organics into simpler compounds. Simple organic matter is attacked by another type of bacterium, a transformer that transforms these organic compounds into an inorganic form suitable for reuse by growers and green plants. Transformers and decomposers play a really important role in maintaining the dynamic nature of ecosystems.

Q11) What are the steps  involved in operation of ecosystem?  (5)

A11) The main steps in the operation of the ecosystem are

The major steps in the operation of an ecosystem involve not only the production, growth and death of biological components, but also the abiotic aspects of the habitat. It is now clear that both energy and nutrients move from producers to consumers, and ultimately to the levels of decomposers and transformers. This transition involves a gradual decrease in energy, but no reduction in nutrient content, indicating a cycle of abiotic to biological and vice versa.

The flow of energy is unidirectional. At the heart of ecosystem dynamics are two ecological processes: energy flow with the interaction of biological and abiotic components and mineral cycling. Figure 3.1 shows the major steps and components of the ecosystem.

Q12) What is food chain and food web?     (5)

A12) Food chain

The food chain is an ideal representation of the flow of energy in an ecosystem. In the food chain, plants and producers are consumed only by primary consumers, and primary consumers are supplied only by secondary consumers. Producers who can produce their own food are called autotrophs. The food chain consists of her three major tropical levels: producer, consumer and decomposer. The energy efficiency of each tropical level is very low. Therefore, the shorter the food chain, the easier it is to access food.

The typical food chain in terrestrial ecosystems progresses as grass rats ——————-> snakes ————> hawks.

Food webs are more complex and interrelated at various tropical levels. Better survival is possible because organisms have multiple food choices. Hawks do not limit their food to snakes, snakes eat animals other than mice, and mice eat grass and grasshoppers. A more realistic picture of eating habits in an ecosystem is called a food web.

Food web:

Charles Elton introduced the concept of the food chain in 1927. This is called the food chain. Charles Elton explained the concept of the food web as follows:

Carnivores prey on herbivores. These herbivores get their energy from the sun. Later carnivores can also be prey to other carnivores. Animals form the end of this food chain until they reach a place free of enemies. There are chains of animals tied together by food, all dependent on plants in the long run.

This is called the food chain, and all food chains in the community are known as food webs. The food web is a graphical representation of the interspecific feeding connections of the ecological community. The food web contains the food chain of a particular ecosystem. Food webs are examples of various feeding technologies that connect ecosystems. Food webs also explain the flow of energy as a result of feeding relationships between species in the community. All food chains are interconnected, overlapped, and form a food web within an ecosystem. In the natural environment and ecosystems, food chain relationships are interrelated. These relationships are very complex because an organism can be part of multiple food chains.

Therefore, a web-like structure is formed instead of the linear food chain.

The network structure formed by connecting the food chains to each other is known as a food network.

The food web is an integral part of the ecosystem. These food webs allow organisms to obtain food from multiple types of organisms with lower nutritional levels.

All living things are responsible and are part of multiple food chains in a given ecosystem.

Q13) What is ecological pyramid? (5)

A13) Ecological Pyramid:

Q14) What are the types of ecological pyramid?  (8)  

A14) Types of pyramids:

1. Pyramid of numbers:

The number pyramid represents the trophic population as the total number of individuals of different species present at each trophic stage. The pyramid of numbers may be upright or completely inverted, depending on the number of individuals present. The pyramid of numbers does not completely define the nutritional structure of an ecosystem, as it is very difficult to count all the organisms that exist there. Pyramid of Numbers-Upright: Meadow Ecosystem In this pyramid, populations decrease from low to high nutritional levels. Examples of numerical pyramids are grassland ecosystems and pond ecosystems. In the grass ecosystem, grass is abundant at the base (minimum nutrient level).

The next highest nutritional level is the primary consumer, the herbivore (eg grasshopper). The number of grasshoppers is less than the number of grasses. The next energy level is the primary carnivore (eg rat). Mice eat grasshoppers, so there are fewer than grasshoppers. The next highest nutritional level is secondary carnivores (eg snakes). They eat mice. The next highest nutritional level is the highest carnivorous animal. (Example-Hawk). When higher nutrition levels are reached, the number of individuals decreases from lower nutrition levels to higher nutrition levels. Pyramid of numbers – upside down: tree ecosystem In this type of pyramid, populations increase from low to high nutritional levels. For example, a tree ecosystem.

2. Biomass Pyramid:

The biomass pyramid represents the total dry weight of an organism. It is usually determined by collecting all organisms that individually invade each trophic stage and measuring their dry weight. This helps solve the problem of size differences as all types of organisms in the vegetative stage are weighed. The unit of measurement for biomass is g / m2. Species biomass is represented by raw or dry weight. Biomass measurements are considered to be more accurate in terms of dry weight. A constant mass of organisms at each trophic stage at a particular time, called a standing crop. Standing crops are measured as the mass (biomass) of an organism or the number per unit area. Biomass Pyramid: Upright The terrestrial biomass pyramid has a large base of primary producers, on which undernutrition levels reside. The producer's biomass, called autotrophs, is at maximum nutritional levels. Biomass from the base to the next nutritional stage, that is, the primary consumer is less than the producer. The next highest nutritional stage biomass, the secondary consumer, is less than the primary consumer. At the highest high nutrition levels, the amount of biomass is very low. On the other hand, in many aquatic ecosystems, the biomass pyramid may exist in an inverted form, while the aquatic ecosystem number pyramid is upright. Because it is a small phytoplankton that grows and reproduces very rapidly. Here, the biomass pyramid has a small base compared to the consumer's biomass, which actually exceeds the producer's biomass, and the pyramid is represented in the opposite way.

3. Pyramid of Energy:

The energy pyramid represents the flow of energy from undernutrition levels to high nutrition levels. There is a significant loss of energy between the flow of energy from one organism to another. This loss of energy occurs in the form of heat. Primary producers, such as autotrophs, contain more available energy.

The least energy available to tertiary consumers.

Therefore, the shorter the food chain, the more energy is available at the highest nutritional stages. The energy pyramid is considered to be the best way to compare the functional roles of the trophic stages in ecosystems. The energy pyramid represents the amount of energy at each nutritional stage and the loss of energy that occurs during the transfer to another nutritional stage. Therefore, the pyramid is always upwards and has a large energy base at the bottom. An ecosystem says he receives 1000 calories of light energy a day. Most of the energy is not absorbed by plants. Some energy is reflected in the universe. Green plants utilize a small portion of the absorbed energy, of which the plant consumes a portion for breathing, and out of 1000 calories, only 100 calories (10%) are stored as energy-rich materials. .. Now suppose an animal eats a plant that contains 100 calories of food energy. The animal uses part of it for its metabolism and stores only 10 calories as food energy.

Q15) What is the scope and importance of environment survey?   (8)

A15) Scope of environmental survey

There are multiple multi-level scopes in the field of environmental research. This study is important

And it's needed for everyone, not just children. The scope is summarized as follows:

1. This study is about various renewable energies

Non-renewable resources in the area. Qualities or possibilities, patterns of use, and the balance of various resources that can be used in the future in a country's condition is analyzed the study.

2. Provide knowledge about ecosystems and causality.

3. Provide the necessary information about biodiversity abundance and potential dangers species of plants, animals and microorganisms in the environment.

4. This study will help you understand the causes and consequences of the main causes naturally.

Induced disasters (floods, earthquakes, landslides, cyclones, etc.) and pollution and their countermeasures minimize the impact.

5. This allows you to evaluate alternative responses to environmental issues. Another course of action.

6. This survey enables environmentally savvy citizens (environmental laws, rights, make appropriate judgments and decisions for protection (rules, laws, etc.) Improvement of the earth.

7. This study reveals issues such as overpopulation, health and hygiene and the role of art, science and technology to eliminate / minimize evil from society.

8. This study identifies, develops, and develops appropriate and indigenous eco-friendly skills, technology for various environmental problems.

9. It teaches citizens the need for sustainable use of resources what has been passed down from generation to generation is passed on to the next generation without sacrificing quality.

10. This study allows you to put your theoretical knowledge into practice and use multiple environments.

Importance of environmental research

Environmental research is based on a comprehensive view of various environmental systems. It aims to empower citizens to do scientific work and find practical solutions to current problems.

Environment issues. Citizens acquire the ability to analyze environmental parameters such as 2.nInteractions between aquatic, terrestrial and atmospheric systems and their biosphere and anthrosphere.

Importance

With the natural environment. It integrates different approaches in the humanities and social sciences. Science, biological science, and physical science, and apply these approaches to research and environmental concerns.

n.   Environmental studies are an important way to change knowledge values, behaviors and lifestyles needed to achieve sustainability and stability at home and abroad country.

Q16) Write a short note on Food web.   (5)

A16) A food web is a detailed interconnect diagram showing the overall food relationships between organisms in a particular environment. This can be explained as a "who eats who" diagram showing the complex feeding relationships of a particular ecosystem.

Research on food webs is important. Because such nets can show how energy flows through the ecosystem. It also helps to understand how toxins and pollutants are concentrated within a particular ecosystem. Examples include the in vivo accumulation of mercury in the Everglades, Florida and the accumulation of mercury in the San Francisco Bay. Food webs also help study and explain how species diversity fits into the overall food dynamics. It may also reveal important information about the relationship between invasive species and species endemic to a particular ecosystem.

The concept of the food web, formerly known as the food chain, is usually due to Charles Sutherland, who was first introduced in his book Animal Ecology, published in 1927. He is considered one of the founders of modern ecology, and his book is an original work. He also introduced other important ecological concepts such as niches and transitions in this book.

In the food net, organisms are arranged according to their nutritional stage. The nutritional stage of an organism refers to how it fits into the entire food web and is based on how the organism feeds. Broadly speaking, there are two main names: autotrophs and heterotrophs. Autotrophs make their own food, but heterotrophs do not. This broad designation has five major nutritional stages: primary producer, primary consumer, secondary consumer, tertiary consumer, and apex predator. The food web shows how these different nutrient stages in the various food chains interconnect with each other, and the flow of energy through the nutrient stages in the ecosystem.

Q17) Explain abiotic components of environment in brief.  (8)

A17) In ecology or biology, abiotic factors or abiotic components are physical parts of the environment and abiotic chemicals. They affect the functioning of ecosystems and organisms. Abiotic components and the phenomena associated with these factors underpin biology as a whole.

Abiotic factors include abiotic resources and physical condition that affect the organism in terms of reproduction, maintenance, and growth.

Resources are distinguished as objects or substances in the environment that a single organism needs, and are either exhausted or otherwise created so that they cannot be used by a variety of other organisms.

Degradation of the constituents of a substance is manifested by physical or chemical processes such as hydrolysis. All abiotic elements of an ecosystem, such as water resources and atmospheric conditions, are known as "abiotic elements".

Examples of abiotic components

Abiotic components include soil, acidity, atmosphere, humidity, temperature, radiation, light, and water in biology. Macroscopic climate often affects all of the above. Sound waves and pressure waves can be considered in terms of the underground or marine environment.

In the marine environment, abiotic components also add tides, solar energy, water clarity, substrates, and aerial exposure. We will also examine the differences in the mechanisms of the CAM, C4, and C3 plants to regulate the influx of carbon dioxide into the Calvin cycle for abiotic stressors.

C3 type plants do not contain a mechanism to control photorespiration.

CAM and C4 type plants, on the other hand, utilize isolated PEP carboxylase enzymes to prevent photorespiration.

Therefore, they are enhancing the production of photosynthetic processes within some high energy platforms.

Various archaea require very high pressures, extraordinary considerations, and temperatures for chemicals such as sulfur.

This is due to characterization in extreme situations.

Fungi have also evolved to survive environmental stability, humidity and temperature.

For example

An important difference in access is the humidity and water between temperate deserts and rainforests. These differences in access to water lead to changes in the various organisms that remain in these locations.

In abiotic components, these differences change the available species by creating boundaries for the species that can live in the environment. They also affect the competition between the two species.

Various abiotic components, such as salt, can provide a single species with the opposite benefits of other species. It creates pressure on specialist and generalist competitors, and through it, causes species change and speciation.

Q18) Explain water cycle with diagram.  (8)

A18) The water cycle, also known as the water cycle, involves a series of steps that indicate the continuous movement and exchange of water between the three phases of the Earth's atmosphere: solid, liquid, and gas. The sun acts as the primary source of energy to power the water cycle on Earth.

Water Cycle Steps: How It Works

1. Liquid-to-gas phase-evaporation and transpiration

The heat of the sun evaporates water from the surface of water bodies such as the sea, streams, and lakes into water vapor in the atmosphere. Plants also contribute to the water cycle as water evaporates from above-ground parts of the plant, such as leaves and stems, during the process of transpiration.

2. Change from solid phase to gas phase – sublimation

Due to dry wind, low humidity and low pressure, the snow on the mountain is directly converted into water vapor, which bypasses the liquid phase by a process called sublimation.

3. Change from gas phase to liquid phase – condensation

Invisible water vapor formed by evaporation, transpiration, and sublimation rises in the atmosphere, and instead cold air rushes through. This is a process of condensation that allows water vapor to return to a liquid, which is stored in the form of clouds.

When the temperature drops sharply, water vapor condenses into small water droplets that can remain suspended in the air. These floating water droplets mix with the dust in the air and create fog.

4. Change from gas phase to liquid phase and solid phase – precipitation and deposition

The movement of the wind causes clouds containing water to collide, and precipitation causes them to fall to the surface of the earth. This is simply called rain. Therefore, the water that evaporates in the first place returns to various waters on the surface, such as the sea, rivers, ponds, and lakes. In extremely cold regions where temperatures are below freezing, water vapor turns directly into frost and snow, bypassing the liquid phase and causing snowfall in the highlands by a process called sedimentation.

5. Water Return to Underground Reserve – Outflow, Penetration, Penetration, and Collection

Water that returns to the surface moves between layers of soil and rock and accumulates as groundwater reservoirs called aquifers. This process is further assisted by earthquakes that help groundwater reach the Earth's mantle. Precipitated water flows along the sides of mountains and hills, reaches the body of water, and evaporates into the atmosphere again. During a volcanic eruption, groundwater returns to the surface and mixes with the surface water to continue circulation.

Q19) Explain tsunami in brief.  (8)

A19) Simply put, a tsunami can be defined as a giant wave that results from an earthquake or subsea volcanic activity. As the waves begin to travel, they continue to reach higher heights. This phenomenon is exacerbated when the depth of the sea is quite shallow. Therefore, in a sense, a tsunami can be characterized by a sudden but incredibly rapid rise in average sea level.

Unlike the general concept, the velocity of an ongoing tsunami does not depend on the distance of the primary wave. Instead, it depends almost entirely on the depth of the ocean. The waves from the tsunami are very fast and slow down only when the shallow water level is reached.

Despite the credibility of this natural phenomenon, it is worth noting that the tsunami is generally a rare event that occurs only once or twice a year anywhere in the world. However, the most devastating tsunami is known to occur once every 10 to 15 years.

Cause of the tsunami

Tsunamis can be caused by a variety of geological activities. Here's what you need to know about these:

1. Earthquake

When an earthquake occurs, a tsunami can occur. Sudden spikes in sea level can be observed as the fault zone moves along the boundaries of the tectonic plates. This will later take the form of a tsunami.

Earthquakes correlate with tsunamis. This is because the strongest earthquakes are observed in subduction areas where various oceanic crusts are under young plates or other continental plates.

However, not all earthquakes cause a tsunami. A tsunami will only occur if the earthquake meets the following conditions:

Earthquakes occur under the sea as one plate moves under another.

It should be very strong with a minimum size of 6.5.

The depth of the earthquake should be shallow enough to destroy the surface of the earth.

Finally, earthquakes also need to cause strong vertical motion on the seafloor.

2. Submarine landslide

Landslides that occur in coastal areas can lead to additional water surges in the sea. This phenomenon affects existing seawater and ultimately causes a tsunami. Landslides at the underwater level can produce the same effect. This is especially common because the particles released by the landslide show strong movement, pushing the nearest water source to higher altitudes.

3. Strong volcanic collapse / slope collapse / eruption

This is less common than other natural phenomena, but violent or strong eruptions can cause sudden confusion and eventually push away large amounts of water. The result is a very destructive tsunami with very strong waves.

In addition to volcanic eruptions, sudden slope failures and explosions can also cause large tsunamis. Perhaps the most prominent example of this event was observed in 1883, when the Krakatoa volcanic collapse raised the tsunami waves to a whopping 135 feet. This event leads to the destruction of villages and small towns on Java and Sumatra. The death toll has exceeded 36,000.

4. Collision from meteorite

This is also a very rare example, but the collision of two or more extraterrestrial particles can cause a tsunami. These particles contain a variety of celestial bodies such as meteorites and asteroids.

Some scientists have discovered that when these particles collide with the ocean floor, they naturally lead to a rise in body of water, which causes a tsunami. However, to achieve this, large asteroids with a diameter of 6 to 8 km or more must collide in the center of a huge basin such as the Atlantic Ocean.

Q20) What is earthquake?  (5)

A20) Earthquakes are caused by sudden slips on faults. The tectonic plate is constantly moving slowly, but is stuck at the edges due to friction. When the stress at the edges overcomes the friction, an earthquake occurs, the energy of the waves is released and travels through the crust, causing the tremors we feel.

There are two plates in California, the Pacific Plate and the North American Plate. The Pacific Plate consists of the Pacific Ocean floor and most of the California coastline. The North American Plate consists of most of the North American continent and part of the Atlantic bottom. The main boundary between these two plates is the San Andreas Fault. The San Andreas Fault is over 650 miles long and extends to a depth of at least 10 miles. Many other small faults, such as Hayward (Northern California) and San Jacinto (Southern California), diverge from the San Andreas Fault Zone.

The Pacific Plate is crushed northwest past the North American Plate at a rate of about 2 inches per year. Part of the San Andreas Fault System adapts to this movement by constant "creeping", resulting in many small impacts and some moderate earthquakes. In other areas where creep is not constant, strain can accumulate for hundreds of years and cause large earthquakes when finally released.