Biology Exam Questions SEM 1

Define Population

Dichotomous key

Describe relationship in graphs

mutualism

In Western Australia, regular prescribed burning of natural bushland and forests is an important management strategy. Prescribed burning practices can reduce the incidence of destructive wildfire by

The primary purpose of prescribed burning is to reduce the amount of combustible material on the forest floor.

• (b) reducing the fuel load. (This is the most direct and comprehensive answer, as fuel load refers to all the flammable material.)

Which sampling method would be most effective at monitoring the progress of newly released marsupials from a captive breeding program?

Monitoring newly released animals requires tracking individuals to observe their movements, survival, and adaptation to the wild.

Radio-tracking. (Allows for real-time or regular tracking of individual animals fitted with transmitters, making it ideal for monitoring their movements, dispersal, and survival after release.)

Agricultural ecosystems are more susceptible to disease and invasion by pests than natural ecosystems. The most likely reason for this is the

• (c) lack of ecosystem stability due to low species diversity.

Explanation: Agricultural ecosystems, especially monocultures (growing a single crop over a large area), inherently have very low species diversity compared to natural ecosystems. This lack of diversity leads to:

• Reduced natural controls: There are fewer natural predators or parasites to keep pest populations in check.

• Widespread susceptibility: If a disease or pest is able to infect one plant in a monoculture, it can easily spread throughout the entire crop because all plants are genetically similar and susceptible. In a diverse natural ecosystem, different species would have varying resistance, slowing the spread.

• Simplified food webs: The ecosystem is less resilient to disturbances as there are fewer alternative pathways for energy flow and nutrient cycling, making it less stable.