1.
Primary succession almost always begins with ...
Correct Answer
B. Bare rock
Explanation
Primary succession almost always begins with bare rock because bare rock provides a completely lifeless and barren surface for colonization. In primary succession, pioneer species like lichens and mosses are the first to colonize the area, breaking down the rock and forming soil over time. These pioneer species pave the way for the establishment of other plant species, gradually transforming the area into a more complex and diverse ecosystem. Bare rock is an ideal starting point for primary succession because it lacks any pre-existing soil or organic matter that could support the growth of other plants.
2.
When one group of species is replaced with others over time, it is called ...
Correct Answer
A. Ecological succession
Explanation
Ecological succession refers to the process of one group of species being gradually replaced by another group of species over a period of time. This change occurs in a specific order, starting with pioneer species and eventually leading to a stable and mature community known as a climax community. Evolution and natural selection, on the other hand, refer to the mechanisms by which species change and adapt over generations, while climax community is the final stage of ecological succession. Therefore, the correct answer is ecological succession.
3.
If a forest fire completely destroys the plant and animal life in a forest, what kind of succession will eventually start restoring it.
Correct Answer
B. Secondary succession
Explanation
Secondary succession is the correct answer because it refers to the process of ecological succession that occurs after a disturbance, such as a forest fire, that completely destroys the existing plant and animal life in an area. In secondary succession, the soil is still intact, allowing for the regeneration of the ecosystem through the colonization of new plant and animal species. This process typically starts with pioneer species, which are able to quickly establish themselves in the disturbed area, and gradually transitions to more complex and diverse communities over time.
4.
On a rock outcrop that has never been home to living organisms, what is likely to be the first organism to grow there?
Correct Answer
D. Lichen
Explanation
Lichen is likely to be the first organism to grow on a rock outcrop that has never been home to living organisms. Lichen is a symbiotic organism composed of a fungus and an alga or cyanobacterium. It is well adapted to colonize harsh and barren environments, such as rocks, by breaking down the rock surface and creating a suitable habitat for other organisms. Therefore, lichen can establish itself and start the process of primary succession, paving the way for the growth of other plants like grass, wildflowers, and algae.
5.
Lichen is a combination of two different organisms. What are they?
Correct Answer
D. Fungus and algae
Explanation
Lichen is a unique organism that is formed by the symbiotic relationship between a fungus and an alga. The fungus provides a protective structure and absorbs nutrients from the environment, while the alga produces food through photosynthesis. This mutually beneficial partnership allows lichen to survive in diverse habitats, such as rocks, trees, and soil.
6.
The first species to colonize a barren area is called a ...
Correct Answer
C. Pioneer species
Explanation
A pioneer species is the first species to colonize a barren area. These species are typically hardy and can tolerate harsh environmental conditions. They play a crucial role in initiating ecological succession by breaking down rocks and creating soil, thus paving the way for other plant species to establish themselves. Pioneer species are often characterized by their ability to reproduce quickly and disperse their seeds over long distances. As the pioneer species create a more favorable environment, they gradually give way to other species, leading to the formation of a more diverse and stable ecosystem.
7.
About how long does secondary succession take before it reaches a climax community?
Correct Answer
B. About 100 years
Explanation
Secondary succession is the process of ecological succession that occurs in an area where an existing ecosystem has been disturbed or destroyed, but the soil is still intact. It involves the gradual development of a new community of plants and animals over time. The given answer of about 100 years suggests that it takes approximately a century for secondary succession to reach a climax community, which is the final stage of succession where the ecosystem is stable and has reached its maximum biodiversity and productivity. This timeframe allows for the gradual colonization, growth, and interactions of different species until a state of equilibrium is achieved.
8.
Which statement is true about forest fires?
Correct Answer
C. Forest fires can sometimes be beneficial for the ecosystem.
Explanation
Forest fires can sometimes be beneficial for the ecosystem because they play a crucial role in the natural cycle of forests. These fires help in clearing out dead vegetation and promoting the growth of new plants. They also release nutrients back into the soil, which can enhance soil fertility. Additionally, certain plant species have adapted to rely on fire for seed germination or to remove competition. Therefore, while forest fires can be destructive and pose risks, they can also have positive effects on the ecosystem.
9.
If succession has reached its climax community, then in about another 500 years what will happen?
Correct Answer
D. If left undisturbed, the climax community will remain stable.
Explanation
If succession has reached its climax community, it means that the ecosystem has reached a state of equilibrium and stability. This means that the community has developed all the necessary species and interactions to sustain itself. Therefore, if left undisturbed, the climax community will remain stable and continue to thrive without any major changes for the next 500 years.
10.
Which statement is true about ecological succession?
Correct Answer
D. The climax community will depend on where succession is occurring.
Explanation
Ecological succession is the process of change in the species composition of a community over time. It involves a series of stages, starting from bare rock or disturbed land and ending with a stable, mature community called the climax community. The climax community that develops depends on various factors such as climate, soil conditions, and the availability of resources. Therefore, the statement that the climax community will depend on where succession is occurring is true, as different environments will lead to the development of different climax communities.