Science M.C.Q

Biomagnification is the increasing concentration of a substance, such as a toxic chemical, in the tissues of tolerant organisms at successively higher levels in a food chain. Humans acquire the maximum of it, as ultimately we are the biggest consumer of every product.

Algae are producers, which prepare their food themselves through photosynthesis. They are not consumers.

Biodegradable is the waste which can be degraded by the activity of microbes. The leather is obtained from the skin of the animals which is degradable. Paper is made from the wood and contains the cellulose which can be degraded by the microbes producing cellulase. Cloth contains cellulosic fibres which can be broken down by the microbes.

In a pond, green algae are the primary producers. Green algae are consumed by mosquito larvae, which therefore become the primary consumers. Mosquito larvae are consumed by fish, which then become the secondary consumers.

The Great Barrier Reef is home to numerous plants and animals, specially corals. The organisms form various food chains and web and all together, they form an ecosystem.

Decomposers convert the organic matter present in the bodies of dead organisms into inorganic forms and mix them with the soil.

An ecosystem is an organization of biotic and abiotic components where the two interact with each other and maintain an energy balance.
Examples of ecosystems are deserts, grasslands, aquatic and tree ecosystems.
Crop fields, aquariums, and cities or towns are man-made ecosystems that are not naturally maintained and are either created or maintained by humans.

Chlorofluorocarbons are the cause of depletion of the atmospheric ozone layer.

c. Dog
Explanation:
Organisms which feeds on both plants and animals is an omnivore. Dog is an omnivore as it feeds on milk, biscuits, meat, etc. Goats and rabbits are herbivores that feed on plants. Wolf is a carnivore that feeds on herbivores.

 

The initial organism of a food chain is the producer, which produces food through photosynthesis.

Depletion of ozone layer is noticed all over the earth.
Ozone is destroyed by collisions with other atoms and molecules.

A forest ecosystem comprises trees, wildlife, and abiotic components. Both plants and animals are dependent on each other for their survival. There are many species that form an integral part of the forest food chain. Trees provide food and shelter whereas, some animals help in the pollination and dispersal of seeds. Thus, when forests are destroyed, it wipes out the entire forest ecosystem.

Green plants are producers that prepare carbohydrates as food from inorganic compounds, such as carbon dioxide and water, by using sunlight as the radiant energy.

The study of the ecosystem is called 'ecology'. The scientists who study the ecosystem are called 'ecologists'.

oceanic biome or ecosystem occupies more than two-thirds of the earth's surface. This is the most stable ecosystem.

(B).  Cake, wood and grass.
(C).  Fruit-peels, cake and lime-juice and,

The concentration of harmful pesticides in the bodies of birds and animals increases at each trophic level, and hence the dog in the given food chain will have the maximum concentration of harmful pesticides.

Grasshopper feeds on grass and hence is a primary consumer. Frogs feed on insects and hence are secondary consumers.

Solid waste that are generated must be segregated as dry waste and wet waste. This would help in better treatment and disposal of waste.

Oxygen is converted into ozone by ultraviolet radiations.

An ecosystem comprising of producers, herbivores carnivores is an incomplete ecosystem. It does not include decomposers.

Autotrophs are organisms that can synthesize their own food some They are called producers.
Herbivores are those organisms that feed on producers. They are called primary consumers.
Carnivores are those organisms that feed on herbivores. They are called secondary consumers.
Decomposers are organisms that feed on dead and decaying matter. They break down the organic matter and release essential nutrients back into the environment.

A jute carry bag is made from jute, which is a plant fibre. Hence, it is biodegradable.