Organisms and Population Chapter-Wise Test 23

Correct answer Carries: 4.

Wrong Answer Carries: -1.

Which of the following is a correct statement about trophic cascades?

They only occur in aquatic ecosystems.
They describe how changes in predator populations affect lower trophic levels.
They have no impact on ecosystem balance.
They only involve herbivores and primary producers.
2

Trophic cascades describe the effects of changes in predator populations on lower trophic levels, influencing ecosystem dynamics.

Which of the following is a density-dependent factor in population regulation?

Earthquake
Hurricane
Food availability
Flood
3

Food availability depends on population density, whereas natural disasters are density-independent factors.

Which type of organism is most likely to be an r-selected species?

Elephants
Tigers
Bacteria
Whales
3

r-selected species, like bacteria, reproduce rapidly with little parental care, while K-selected species, like elephants and whales, have slower reproduction.

Which of the following factors is density-dependent?

Flood
Earthquake
Disease
Temperature change
3

Disease is a density-dependent factor because its spread increases with population density.

Which of the following is an incorrect statement about mutualism?

Both species benefit from the relationship.
It is a type of symbiotic interaction.
One species benefits while the other is harmed.
Pollination by bees is an example of mutualism.
3

Mutualism is a symbiotic relationship in which both species benefit, unlike parasitism, where one species is harmed.

Which of the following is NOT a factor affecting population growth?

Natality
Mortality
Mutation
Immigration
3

Mutation affects genetic variation but does not directly influence population growth like natality, mortality, and migration.

Which term describes the number of individuals per unit area in a population?

Population size
Population density
Carrying capacity
Age structure
2

Population density refers to the number of individuals in a given area or volume.

Which of the following is an example of amensalism?

Cattle egret benefiting from grazing cattle
Penicillium releasing antibiotics that kill bacteria
Tiger preying on a deer
Orchid growing on a tree
2

Amensalism occurs when one species is harmed while the other remains unaffected, as seen in Penicillium inhibiting bacterial growth.

Which of the following best explains why populations fluctuate over time?

Changes in birth and death rates
Stable environmental conditions
Consistent availability of resources
Absence of competition
1

Fluctuations in birth and death rates due to environmental factors and resource availability lead to population changes over time.

Which of the following is a correct statement about invasive species?

They always increase biodiversity.
They can disrupt ecosystem stability by outcompeting native species.
They always require human introduction.
They have no effect on native species.
2

Invasive species often outcompete native species, reducing biodiversity and altering ecosystem dynamics.

Performance Summary

Score:

Category Details
Total Attempts:
Total Skipped:
Total Wrong Answers:
Total Correct Answers:
Time Taken:
Average Time Taken per Question:
Accuracy:
0