Organisms and Population Chapter-Wise Test 20

Correct answer Carries: 4.

Wrong Answer Carries: -1.

Which of the following correctly defines "population dispersion"?

The movement of individuals into a population
The spatial distribution of individuals within a habitat
The number of individuals per unit area
The change in population size over time
2

Population dispersion refers to how individuals are spaced within their habitat, which may be clumped, uniform, or random.

Which of the following is a correct statement about decomposers?

Decomposers only feed on living organisms.
They break down organic matter and recycle nutrients into the ecosystem.
Decomposers only exist in aquatic ecosystems.
They have no role in nutrient cycling.
2

Decomposers break down dead organic material and return essential nutrients to the ecosystem.

Which type of survivorship curve is characterized by high juvenile mortality but long survival for those that reach adulthood?

Type I
Type II
Type III
Logistic curve
3

Type III survivorship curves, seen in species like frogs and oysters, have high juvenile mortality but long survival for adults.

Which of the following is an example of mimicry?

A moth resembling a dead leaf
A fish laying many eggs
A tree developing deep roots
A cactus storing water
1

Mimicry occurs when an organism resembles another object or species to avoid predation, as in the case of a moth resembling a dead leaf.

Which of the following best describes a fundamental niche?

The actual space an organism occupies due to competition
The full range of conditions and resources a species can use in the absence of competition
The place where an organism builds its nest
The interactions between predators and prey
2

A fundamental niche includes all the possible conditions under which a species can exist without competition.

Which term describes a relationship where one species harms another but is unaffected itself?

Mutualism
Commensalism
Parasitism
Amensalism
4

Amensalism occurs when one species is harmed while the other remains unaffected, such as when a tree releases chemicals that inhibit the growth of nearby plants.

Which of the following is an incorrect statement about the carbon cycle?

Photosynthesis removes carbon dioxide from the atmosphere.
Respiration releases carbon dioxide back into the atmosphere.
Carbon is only cycled through terrestrial ecosystems.
Fossil fuel combustion increases atmospheric carbon dioxide levels.
3

The carbon cycle occurs in both terrestrial and aquatic ecosystems, involving biological, geological, and chemical processes.

Which of the following statements about ecological pyramids is incorrect?

Pyramids of energy are always upright.
Pyramids of biomass can sometimes be inverted.
Pyramids of numbers always decrease at higher trophic levels.
Ecological pyramids represent energy flow and biomass distribution.
3

Pyramids of numbers can sometimes be inverted, such as in forests where a few large producers support many herbivores.

Which of the following organisms is an example of an r-selected species?

Elephants
Humans
Bacteria
Tigers
3

r-selected species, like bacteria, reproduce rapidly with minimal parental care.

Which of the following is a characteristic of K-selected species?

Short lifespan
High parental care
Rapid reproduction
Low survival rate of offspring
2

K-selected species invest in high parental care, ensuring the survival of fewer but more competitive offspring.

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