Ecology And Environment

Three diagnostic techniques for the detection of cancer are: Biopsy: A small tissue sample is removed from the suspected area and examined under a microscope to detect cancerous cells. Imaging Techniques: {X-rays:} Used to detect abnormalities in bones or organs. {MRI (Magnetic Resonance Imaging):} Provides detailed images of soft tissues to detect tumors. Blood Tests: Detect tumor markers (specific proteins or substances) produced by cancer cells.

The disorder is caused by a point mutation in the -globin gene, resulting in the substitution of glutamic acid with valine at the sixth position of the haemoglobin molecule. This mutation causes haemoglobin molecules to polymerize under low oxygen conditions, leading to the characteristic sickle shape of red blood cells.

Step 1 (a): Activated sludge refers to the thick, flocculent mass of bacteria and fungi formed in the aeration tank of a Sewage Treatment Plant (STP). These microbial flocs actively digest the organic matter present in sewage.
Step 2 (b): After aerobic treatment in the aeration tank, the major part of the sludge is transferred to anaerobic sludge digesters, where:

• Anaerobic bacteria break down the organic matter in the absence of oxygen.
• This process releases biogases such as methane, carbon dioxide, and hydrogen sulfide.
• The digested sludge settles at the bottom and is used as manure, while the treated water is released into water bodies after disinfection.

Step 1: (a) The full form of BOD is Biochemical Oxygen Demand.
Step 2: (b) BOD is the amount of dissolved oxygen needed by aerobic microorganisms to break down organic matter present in a water sample.

• A higher BOD indicates more organic pollution and microbial activity.
• It is an indicator of the level of biodegradable organic matter in the water body.

• In aquatic ecosystems: Grazing food chain.
• In terrestrial ecosystems: Detritus food chain.
• Differences:
  • In the grazing food chain, energy flow begins from producers (phytoplankton or plants), while in detritus food chain, it begins from dead organic matter.
  • The grazing food chain is the major energy flow route in aquatic systems, whereas detritus food chain dominates in terrestrial systems.

• Habitat loss and fragmentation reduce the available area for wildlife, restricting food, shelter and breeding grounds.
• Fragmentation divides populations into small, isolated groups, leading to inbreeding and reduced genetic diversity.
• An example is the clearing of Tropical Rain Forests for agriculture and settlements, which leads to species extinction.
• Fragmentation causes edge effects, making populations more vulnerable to predators and environmental changes.

To solve this problem, we need to illustrate the ecological pyramid of biomass in the sea and describe its components, showing the trophic levels and how the different organisms are related.

1. Understanding the Ecological Pyramid of Biomass:

An ecological pyramid of biomass shows the amount of living material (biomass) present in different trophic levels of an ecosystem. In marine ecosystems, it is usually represented as a pyramid with the base having the producers (phytoplankton), followed by the consumers at higher trophic levels (zooplankton, small fishes, etc.).

2. Trophic Levels:

• Trophic Level 1: Producers – Phytoplankton, which are the primary producers, form the base of the pyramid.
• Trophic Level 2: Primary Consumers – Zooplankton that feed on phytoplankton.
• Trophic Level 3: Secondary Consumers – Small fishes that feed on zooplankton.

3. Given Values:

Standing Crop of Phytoplankton: 40 units
Standing Crop of Zooplankton: 90 units
Standing Crop of Small Fishes: 120 units

4. Calculating and Depicting the Ecological Pyramid:

We can create the ecological pyramid of biomass based on the given standing crops. The pyramid has the following shape:

• Phytoplankton (Trophic Level 1): 40 units of biomass.
• Zooplankton (Trophic Level 2): 90 units of biomass.
• Small Fishes (Trophic Level 3): 120 units of biomass.

From the data, we can observe that the biomass increases as we move up the pyramid, which is contrary to the general shape of an ecological pyramid where the biomass typically decreases with higher trophic levels. However, this could occur in specific cases where the organisms at higher trophic levels are more efficient in converting biomass into their own bodies.

5. Final Answer:

The ecological pyramid in the sea would look as follows:

• Trophic Level 1 (Phytoplankton): 40 units
• Trophic Level 2 (Zooplankton): 90 units
• Trophic Level 3 (Small Fishes): 120 units

This representation is an example where the biomass does not decrease as we move from lower to higher trophic levels, which is unusual but can occur in certain ecosystems, such as in marine environments with highly efficient energy transfer.