BIOLOGY MCQ

Low stability and high resilience.

Ecological succession is the process of change in the species structure of an ecological community over time. The community begins with relatively few pioneer plants and animals and gradually develops stable or self-perpetuating species as a climax community.

Gause’s hypothesis.

Sere is a sequence of developmental stages from pioneer to climax communities. Plants that are first to invade a bare area are called as pioneer species.

Azotobacter.

Zooplankton.

Biological community and component of the physical environment with which the community interacts.

Phytoplanktons.

Standing crop.

Species that determine structure of biotic community

Mutualism.

Stratification.

Random mating.

The gradual change in the species structure of an ecological community is known as ecological succession. A climax community is the final community formed when the ecological succession becomes stable. It remains relatively unchanged until destroyed by an event such as fire or human interference. It is also known as a stable biological community.

The lithosphere is the solid crust or the hard top layer of the earth. It is made up of rocks and minerals.
The biosphere is a biologically inhabited part of earth along with its physical environment consisting of lower atmosphere, land, and water bodies.
The hydrosphere is the total amount of water on a planet.
An atmosphere is a layer of gas or layers of gases that envelope a planet and is held in place by the gravity of the planetary body.

Succession

Unidirectional.

Tertiary consumer.

Phosphorus cycle is an example for sedimentary cycle.
A cycle which comprises the weathering of an existing rock, followed by the erosion of minerals, their transport and deposition, then burial, is called as sedimentary cycle.
First cycle sediments are characterized by the presence of less resistant minerals and rock fragments.
If this material is reworked through a second cycle, the less resistant minerals will be eliminated or altered to more stable products.
The more sedimentary cycles, that a sediment has passed through the more mature, it will become and it will be dominated by well rounded resistant minerals.

Green food.

The ecosystem is a segment of nature or biosphere consisting of a community of living beings and the abiotic or physical environment both interacting and exchanging materials between them. The ecosystem is defined as a functional unit of environment, which is independent and self-sustaining due to various interactions between abiotic and biotic components and different organisms among themselves.

Always upright

Littoral zone.

Climax community is in a state of equilibrium.

The plants or the other autotrophic organisms which can prepare food require sunlight. In a cave, there will be very less availability of sunlight and hence primary productivity due to photosynthesis by green plants will be very low.
Hence, a cave ecosystem is most unsuitable for primary productivity.

The succession which thus takes place through the process of living, growing and interactions of organisms with the effect of the environment within an area is referred as biotic succession.
Geographical succession is the directional change in the plant and animal community over a period of time in a specific area.
Physiographic succession is the directional change in the plant and animal community over a period of time in a specific area due to physical factors.
Climate succession is the directional change in the living community in a particular area over a period of time due to prevailing climatic conditions.

All of the above.

All of the above.

It is similar to primary succession, but has arelatively fast pace.

The appearance of living organisms on disturbed or damaged habitat is referred to as secondary succession.
Primary succession occurs in a barren land where no life existed before.
So, flooded land abandoned croplands and the area where organisms existed before exhibit the secondary succession.

Tropical Rain Forest.

In tropical rain forest, there is ambient temperature, good moisture and plenty of sugar in detritus. Due to this, rate of decomposition would be fast.

Decreases at each higher trophic level.

The total quantity of solar energy converted into chemical energy by green plant is known as gross primary production.
A portion of gross production is used by the producers for their various metabolic activities.The remainder of energy after utilization is called as net primary production.