Ecosystem

The global ecosystem is known as biosphere.

Autotrophs are organisms that can produce their own food using light, water, carbon dioxide, or other chemicals, typically through photosynthesis.

In an ecosystem, producers (plants and algae) form the base of the energy pyramid and typically possess the greatest total biomass compared to higher trophic levels.

Heterotrophs are organisms that cannot produce their own food and must obtain energy by consuming other organic substances, such as plants or animals.

Due to energy loss at each transfer level (the 10% rule), the biomass at the top of the food chain is significantly smaller than at the producer level.

An aquarium is a self-contained, artificial environment that mimics a natural ecosystem, containing both biotic (fish, plants) and abiotic (water, light, substrate) components.

An ecosystem is defined as a community of living organisms (biotic) interacting with the non-living (abiotic) components of their environment as a system.

The standard taxonomic hierarchy from broadest to most specific is: Kingdom, Phylum, Class, Order, Family, Genus, Species.

Abiotic factors are the non-living components of an ecosystem. Oxygen is a chemical element and a non-living component, whereas leaves and fish are biotic components.

Nitrogen (N2) makes up approximately 78 percent of Earth's atmosphere, making it the most abundant gas in the air.

A biome is a large naturally occurring community of flora and fauna occupying a major habitat, defined by its specific climate and geographical conditions.

Nocturnal animals are those that are active during the night. Among the choices, the bat is the only animal primarily active at night.

Bats are well-known nocturnal mammals that hunt and are active during the night. While some lions and snakes can be active at night, bats are strictly categorized as nocturnal.

Biological magnification (or biomagnification) is the process where the concentration of toxic substances, like DDT, increases at each successive trophic level in a food chain.

Amino acids are the building blocks of proteins and are characterized by the presence of an amino group, which contains nitrogen.

A producer is an organism that produces its own food through photosynthesis, such as plants. A lion is a carnivore, which is a consumer, not a producer.

All the provided statements are standard ecological principles: smaller animals are generally more numerous, biomass is limited by trophic efficiency, and predators are typically larger than their prey.

Nitrogen fixation is the process of converting atmospheric nitrogen into compounds like ammonia or nitrates. While the term 'nitrogenation' is not standard, it is the only option here referring to the fixation process.

Lightning provides the high energy required to break the strong triple bonds of atmospheric nitrogen, allowing it to react with oxygen and form nitrogen oxides that eventually reach the soil.

Nitrosomonas is a genus of bacteria that oxidizes ammonia into nitrites, which is the first step of the nitrification process.

Ammonia consists of one nitrogen atom covalently bonded to three hydrogen atoms, represented by the chemical formula NH3.

Carbon is a fundamental element of life and is cycled through biological processes, not accumulated as a persistent toxic pollutant in the way heavy metals or DDT are.

Urea is an organic compound with the chemical formula (NH2)2CO, commonly produced by the liver and excreted in urine.

Xerophytes are plants adapted to survive in environments with little liquid water, such as deserts or ice-covered regions.

The leaf size is reduced in xerophytes to reduce evaporation and loss of water.

Biotic factors are living components of an ecosystem. pH is a measure of acidity or alkalinity, which is an abiotic (non-living) chemical property.

The environment includes both physical (abiotic) and biotic factors. Statement A is incorrect because it claims the environment includes only physical factors.

Natural calamities are events caused by natural forces. War is a human-made conflict and is not classified as a natural calamity.

Herbivores eat producers (plants) and are therefore the first level of consumers in a food chain, known as primary consumers.

A trophic level is the position an organism occupies in a food chain, representing its feeding stage.

During respiration, organisms break down glucose and release carbon dioxide as a byproduct, which returns carbon to the atmosphere.

Primary consumers eat plants. Secondary consumers eat primary consumers (herbivores).