Prentice Hall Biology (California)
1st Edition
ISBN: 9780132013529
Textbook solutions
All Solutions
Page 83: Chapter 3 Assessment
Exercise 1
Step 1
1 of 3
**Biosphere** is consists of all life on Earth and all of its other parts in which life can exist, this includes land, water, and atmosphere. It contains various organisms that interact with each other. Living things are arranged and organized in their given habitats in different levels which makes up the structure of the organization.
Step 2
2 of 3
Hence, the correct answer is **C**
Result
3 of 3
C
Exercise 2
Solution 1
Solution 2
Step 1
1 of 6
**Population** is the term to defined the group of the organisms of the *same species that live in a specific habitat at the same time*
Step 2
2 of 6
**Community** is the term to describe the *various group of species interacting with each other* in a common habitat.
Step 3
3 of 6
**Ecosystem** is a biological community of living organisms that interacts with their physical (nonliving) environment.
Step 4
4 of 6
**Biosphere** is consists of all life on Earth and all of its other parts in which life can exist, this includes land, water, and atmosphere. It contains various organisms that interact with each other.
Step 5
5 of 6
Hence, the correct answer is **B**
Result
6 of 6
B
Step 1
1 of 5
a. is not correct because a population refers to a group of organisms of the same species in a defined area
Step 2
2 of 5
b. is correct because a community refers to a number of groups of organisms of different species that all live in the same defined area.
Step 3
3 of 5
c. is incorrect because an ecosystem includes non-living things such as a lake or a mountain as well as the organisms in a defined area.
Step 4
4 of 5
d. is also incorrect despite the fact that the biosphere contains organisms of many different species, because the biosphere is not a very well defined area.
Result
5 of 5
b. is the correct choice
Exercise 3
Solution 1
Solution 2
Step 1
1 of 2
Autotrophs are organisms that do not consume any other organisms in order to gather enough energy to maintain metabolism and cellular respiration. Autotrophs take in energy from abiotic elements of their ecosystems. For example, autotrophic plants go through photosynthesis, a process in which they draw energy from sunlight, to enable them to assemble glucose molecules from their molecular components.
Result
2 of 2
C. is the answer, because it is the only answer that describes autotrophs as organisms that get their energy from the environment and not from other organisms.
Step 1
1 of 2
Autotrophs are organisms that synthesize their own energy, usually by absorbing energy from the surroundings, instead of consuming energy within other organisms. Examples include plants and fungi.
Result
2 of 2
C.
Exercise 4
Solution 1
Solution 2
Step 1
1 of 2
a. is correct because the question describes a progression of energy through a system (which both food chains and food webs do), yet it remains simple and one-directional (which a food web is not).
Result
2 of 2
a. food chain is the correct choice
Step 1
1 of 3
The feeding relationships between a large fish, a small fish, and an alga can be represented using a **food chain**. A food chain consists of a series of steps that depict different trophic levels.
Step 2
2 of 3
In this case, a food chain can describe how a large fish eats a small fish that has eaten algae. Organisms in a lower trophic level may be consumed by organisms at a higher trophic level.
Result
3 of 3
B
Exercise 5
Solution 1
Solution 2
Step 1
1 of 3
**Decomposers** feed by breaking down chemically the organic matter in which they inhabit. In fact, decomposers are the ones that produce detritus. Examples of decomposer are worms, fungi, and bacteria
Step 2
2 of 3
Hence, the correct answer is **C**
Result
3 of 3
C
Step 1
1 of 2
Decomposers are organisms that generally live underground and feed on decaying matter, while recycling it into useful nutrients for autotrophs. Worms best fit this description.
Result
2 of 2
C.
Exercise 6
Step 1
1 of 6
**Energy of pyramid** shows the flow or how much of the energy is transferred from tropic level to another in another.
Step 2
2 of 6
**Pyramid of numbers** gives the total number of individual species or organisms at each level in the food chain for a certain ecosystem.
Step 3
3 of 6
**Pyramid of biomass** shows the different biomass present in the trophic levels in the food chain within an ecosystem. The diagram shows the number of biomass in each trophic level needed to support the next trophic level
Step 4
4 of 6
**Biogeochemical cycle** are the various natural pathways by which essential elements in the biosphere are circulated through biotic and abiotic factors.
Step 5
5 of 6
Hence, from the given definitions above, the correct answer is **C**
Result
6 of 6
C
Exercise 7
Step 1
1 of 5
**Biogeochemical cycle** are the various natural pathways by which essential elements that form nutrients in the biosphere are circulated through biotic and abiotic factors.
Step 2
2 of 5
**Water cycle** shows and describes the continuous movement of water molecules within the Earth and its atmosphere.
Step 3
3 of 5
**Energy of pyramid** shows the flow or how much of the energy is transferred from tropic level to another in another.
Step 4
4 of 5
**Ecological pyramid** is a representation of the relationship between organisms present in various trophic levels in an ecosystem.
Step 5
5 of 5
Hence, the correct answer **A**
Exercise 8
Solution 1
Solution 2
Step 1
1 of 2
D, because it changes nitrogen into ammonia
Result
2 of 2
D, change nitrogen gas into ammonia.
Step 1
1 of 3
In the nitrogen cycle, bacteria that typically live on the roots of plants are known as *nitrogen-fixing* bacteria. This type of bacteria can fix nitrogen by *converting nitrogen gas into ammonia*.
Step 2
2 of 3
Due to their ability to fix nitrogen, nitrogen-fixing bacteria often form a symbiotic relationship with plants such as legumes. They play an important role in making nitrogen available for plants.
Result
3 of 3
D
Exercise 9
Step 1
1 of 2
In the water cycle, water enters the atmosphere when it is evaporated into gas.
In the Carbon cycle, carbon enters the atmosphere in the form of $CO_2$ gas.
In the nitrogen cycle, nitrogen enters the atmosphere in the form of nitrogen gas.
Only the phosphorus cycle only involves on land and underground conversions.
Result
2 of 2
phosphorus cycle
Exercise 10
Solution 1
Solution 2
Step 1
1 of 2
A limiting nutrient is a nutrient that is scarce in an ecosystem to an extent that it significantly limits the ecosystem’s carrying capacity.
Result
2 of 2
limiting nutrient
Step 1
1 of 3
When the biological growth of an ecosystem is limited by the scarcity or unavailability of a particular nutrient with respect to other nutrients that are necessary for the growth of organisms, then that nutrient is known as a **limiting nutrient**.
Step 2
2 of 3
Some examples of limiting nutrients are nitrogen and phosphorus. When these nutrients are scarce or unavailable in an aquatic ecosystem such as a lake or pond, the growth of algae and/or other organisms would be limited or significantly reduced.
Result
3 of 3
D
Exercise 11
Solution 1
Solution 2
Step 1
1 of 1
Ecology is the study of how organisms interact with each other and their environment on a broad scale.
Step 1
1 of 3
Ecology is generally defined as the study of ecosystems. To be more specific, ecology is defined as the study of the relationships between living organisms and their physical environment.
Step 2
2 of 3
Ecologists aim to understand the vital connections between living organisms such as plants, animals, and humans and the physical world around them. They are also interested in studying the benefits and ecological services provided by ecosystems.
Step 3
3 of 3
One of the most important aspects of ecology is understanding how to use the Earth’s resources in a sustainable way. It may also deal with how to conserve these resources for future use.
Exercise 12
Step 1
1 of 3
**Biosphere** is consists of all life on Earth and all of its other parts in which life can exist, this includes land, water, and atmosphere. It contains various organisms that interact with each other.
Step 2
2 of 3
Living things are arranged and organized in their given habitats in different levels which makes up the structure of an organization.
Step 3
3 of 3
These levels are: **Individual organism, population, community, ecosystem, biome,** and **biosphere**
Exercise 13
Result
1 of 1
A model is a simplified representation of an object or an idea that describes an event that is too complex, too big or too small to study in real life. These models come in handy when studying ecological changes because scientists couldn’t fit the entire biosphere into the laboratory to study it. For example, scientists can use modeling to study the effect of a volcanic eruption on the ecosystem. Since a volcanic eruption is too complicated and too dangerous to study in an actual environment, a model can be useful in understanding its conditions.
Exercise 14
Solution 1
Solution 2
Step 1
1 of 1
Most ecosystems rely on autotrophs that perform photosynthesis. Photosynthesis is the conversion of carbon dioxide into sugar through energy supplied by sunlight, which means photosynthesis can only work with sunlight. Sunlight is important because if there is no sunlight, then there would be photosynthesis and no plants and that would cause the entire ecosystem to die out because consumers have nothing to eat.
Step 1
1 of 3
Sunlight is the ultimate source of energy for all living organisms. It is captured and used by autotrophic organisms such as plants and algae for photosynthesis, which produces food.
Step 2
2 of 3
Most ecosystems rely on its primary producers such as autotrophic organisms in order to produce food. If sunlight is absent, then these organisms cannot undergo photosynthesis.
Step 3
3 of 3
Without photosynthesis, the primary producers cannot produce their own food. This would cause the ecosystem to collapse since other organisms would not be able to obtain their food.
Exercise 15
Result
1 of 1
There are organisms which are living in places, such as undersea vents or deep-ocean floor, where the sunlight can’t reach them. Instead of relying on light and photosynthesis, these organisms use inorganic chemicals to produce energy through a process called chemosynthesis. Since chemosynthesis does not need energy from the sun, it uses hydrogen gas, hydrogen sulfide, and methane as sources of energy to produce carbohydrates.
Exercise 16
Solution 1
Solution 2
Step 1
1 of 1
Autotrophs are organisms that survive by producing their own energy and carbohydrate. Examples include corn and mushrooms. They generally use the process of photosynthesis or chemosynthesis.
Heterotrophs are organisms that survive by consuming other organisms to get their energy. Examples include rabbits, wolves, and humans.
Step 1
1 of 3
**Autotrophs** are organisms that are capable of producing their own food. Some examples of autotrophs include plants and algae, which can produce their own food through photosynthesis.
Step 2
2 of 3
In contrast, **heterotrophs** are organisms that cannot produce their own food. Some examples of heterotrophs include animals and fungi, which obtain their food from the environment.
Step 3
3 of 3
It is important to note the heterotrophs rely on autotrophs for the production of food. Without autotrophs, heterotrophs would not be able to obtain food and the ecosystem would collapse.
Exercise 17
Solution 1
Solution 2
Step 1
1 of 1
Decomposers are organisms that consume dead and decaying matter and convert this dead matter into nutrients that are useful for autotrophs. They are critical in recycling the matter in an ecosystem. Examples include worms and other annelids.
Step 1
1 of 3
**Decomposers** are organisms that can break down dead or decaying organic matter into simpler materials. These organisms are crucial in recycling materials (nutrients) in an ecosystem.
Step 2
2 of 3
Some examples of decomposers include bacteria, fungi, and annelids such as earthworms. These organisms break down organic matter into nutrients that can be taken up by plants.
Step 3
3 of 3
Therefore, decomposers play an essential ecological role in making nutrients more available for autotrophs. This allows for the recycling of nutrients and thus help in sustaining the ecosystem.
Exercise 18
Solution 1
Solution 2
Step 1
1 of 1
Autotrophs are always at the lowest level in a food chain because they do not consume other organisms but are very commonly consumed by heterotrophs. They also contain the most energy so it’s reasonable that they are at a lower level so the higher level organisms can still have some energy left once the energy depletes along the chain (only 10$%$ of energy is transferred from one level of a food chain to another).
Step 1
1 of 3
**Autotrophs** such as plants and algae are always found at the base of a food chain or food web. This is because they can produce their own food that can be consumed by other organisms.
Step 2
2 of 3
Additionally, autotrophs are the only organisms that can directly use the energy from the sun to produce food. Hence, autotrophs usually have a lot of available energy stored in their bodies.
Step 3
3 of 3
Therefore, it would make sense that autotrophs are located at the base of a food chain or food web since they can provide energy for heterotrophs that cannot produce their own food.
Exercise 19
Solution 1
Solution 2
Step 1
1 of 2
The three types of ecological pyramids are: energy pyramid, biomass pyramid, and the pyramid of numbers. The energy pyramid has many trophic levels where the bottom-most level belongs to the producers followed by different levels of consumers. The amount of energy that can be passed from one trophic level to another is about $10 %$. All the other energy is lost as heat. The biomass pyramid represents the amount of living organic matter at each trophic level, with the greatest biomass being at the base of the pyramid. Another way of putting it is that the pyramid represents the amount of potential food available for each trophic level in any ecosystem. The last pyramid is the pyramid of numbers, which shows the number of individuals at each trophic level.
Result
2 of 2
See solution explanation.
Step 1
1 of 5
An **ecological pyramid** is a graphical representation that illustrates the relationships between organisms at different trophic levels in an ecosystem. Ecological pyramids usually depict a food chain or food web.
Step 2
2 of 5
There are three types of ecological pyramids. These include the pyramid of **numbers**, pyramid of **biomass**, and pyramid of **energy**. Each type of pyramid represents the relationships between organisms based on a particular factor.
Step 3
3 of 5
The *pyramid of numbers* represents organisms based on their numbers or population size. Autotrophs such as plants and algae usually comprise the base of this pyramid, while highest-level consumers such as predator animals are located at the top of the pyramid.
Step 4
4 of 5
The *pyramid of biomass* represents organisms based on their biomass or total dry weight. Similar to the pyramid of numbers, autotrophs would also usually comprise the base of this pyramid due to their large numbers, which constitutes a larger biomass.
Step 5
5 of 5
Lastly, the *pyramid of energy* represents organisms based on the amount of energy stored within them that is available for organisms at a higher trophic level. Again, autotrophs usually comprise the base of this pyramid since they usually store the most amount of energy.
Exercise 20
Solution 1
Solution 2
Step 1
1 of 1
We can explain this by looking at the different processes occurring in an organism that requires energy. Most of the energy consumed by them is utilized for the life processes such as metabolism and survival which only leaves about 10% of the energy available for the next trophic level.
Step 1
1 of 1
Transfer of energy along food chain levels is only ten percent efficient because organisms have to use the majority of the energy they get to build themselves and run life-sustaining functions, such as breathing, reproduction, and movement. This leaves a low proportion of energy to pass on to the next level.
Exercise 21
Result
1 of 1
The biogeochemical cycle involves the circular flow of matter around the biosphere. This cycle is classified into three cycles namely, biological processes, which consists of all the activities of living organisms; geological processes that include movements of matter in the Earth’s surface; and chemical and physical processes that occur within the three states of matter.
Exercise 22
Step 1
1 of 3
**Water** moves continuously between the oceans, seas, lakes, atmosphere, and land. Water molecules enter the atmosphere from the oceans and other water bodies through water vapor in the process of ***evaporation***. This vapor then condenses and forms the cloud. When the droplets become large enough, they fall into the Earth’s land surface in the form of rain, snow, or hail through the process of ***precipitation***
Step 2
2 of 3
Precipitation can also be absorbed into the soil and this will be called *groundwater*. Groundwater enters the plants through the absorption of their roots, from there the water can be brought back into the atmosphere through the process of ***transpiration***
Step 3
3 of 3
Hence, the two processes involved in bringing water back to the atmosphere are **evaporation and transpiration**
Exercise 23
Step 1
1 of 2
**Nitrogen fixation** is the chemical process by which atmospheric nitrogen is converted into nitrogenous compounds such as ammonia, nitrates, and nitrites which can be utilized by plants and other organisms.
Step 2
2 of 2
Nitrogen fixation is usually done by those bacteria that are present in the soil and roots of the plants. Certain types of bacteria such as *Agrobacterium tumafaciens* use atmospheric nitrogen directly and fix it into a usable form of nitrogen for the primary producers.
Exercise 24
Step 1
1 of 1
**Nutrient limitation** is the concept that explains if there is an adequate amount of sunlight and water available for the primary producers, the production process in an ecosystem may be limited by the *nutrient availability*
Exercise 25
Solution 1
Solution 2
Step 1
1 of 1
Nutrient limitation is when a certain nutrient has only limited amounts in an ecosystem that it affects the ecosystem’s carrying capacity. This means that because the nutrient is limited and all organisms in the ecosystem require it, there is only a limited number of organisms that can get the nutrient so only these organisms survive.
Step 1
1 of 3
**Nutrient limitation** is a phenomenon that occurs in an ecosystem when a particular nutrient (called the *limiting* nutrient) becomes scarce or unavailable with respect to other nutrients that are essential for the growth of organisms.
Step 2
2 of 3
As an example, nutrient limitation occurs when an aquatic ecosystem such as a lake or a pond lacks an important nutrient for growth such as nitrogen or phosphorus. The lack of this nutrient limits the growth of aquatic organisms such as algae.
Step 3
3 of 3
Therefore, nutrient limitation could result in the consequence of lowering an ecosystem’s carrying capacity. If the growth of autotrophs is limited by the unavailability of a particular nutrient, then the growth of other organisms that depend on them would also be limited.
Exercise 26
Result
1 of 1
When the surface runoff from the heavily fertilized fields goes into the stream, the result is the increase of algae. This happens due to the nutrients from the nitrogen fertilizer which were absorbed by the algae. Eventually, the algae will start to cover the surface of the water. Because of this, the oxygen in water is reduced and the sunlight is blocked. The algae will create a dead zone wherein there is little or no oxygen at all. As a result, trouts experience death due to hypoxia.
Exercise 27
Result
1 of 1
A food chain shows how energy is transferred using a linear path. For an instance, a phytoplankton is eaten by a zooplankton. Then, the zooplankton is consumed by the herring. In turn, the herring is eaten by the bluefin tuna, and humans consume the tuna.
Exercise 28
Solution 1
Solution 2
Step 1
1 of 2
One new way that water is wasted is with plastic water bottles. Today many people are aware that the plastic water bottles release tiny amounts of toxic chemicals into the bottled water and over time (especially if left in a warm place like inside of a car) the chemical amounts in the water increase. The best thing to do, according to some people is to throw away the water (which is why bottled water has an expiration date). This increase in wasted water can be entirely avoided if people would stop using these types of bottles and if companies would find a different type of plastic or recyclable material to use instead.
Result
2 of 2
See solution explanation.
Step 1
1 of 4
In the community, water could be wasted by excessive usage when washing or cleaning. Flushing frequently and leaving a faucet running when not in use can also waste a lot of water.
Step 2
2 of 4
There are many ways that we can do in the community to limit the amount of water wasted. Some examples include using less water for cleaning and closing faucets when not in use.
Step 3
3 of 4
One of the best ways to limit wasting water is by not polluting the water reservoir. Pollution can waste a lot of water that could be used by the community for their everyday activities.
Step 4
4 of 4
Water consumption can also be reduced in ways that do not require a large change in lifestyle. One can take shorter showers and flush less frequently in order to conserve water at home.
Exercise 29
Result
1 of 1
The data shows an uphill pattern that moves from the lower left to the upper right of the graph. This indicates a positive correlation between the two variables. As the X-values or the average annual rainfall increases, the Y-values or the rate of plant tissue production tends to increase as well. Another factor which may affect the productivity is the sunlight. The light coming from the sun is an important factor in photosynthesis. If there is an absence of sunlight, it may hinder the productivity and growth rate of plants.
Exercise 30
Step 1
1 of 6
The given examples are **earthworm, bear, cow, snail, owl, and human**. Let us define first what are **herbivore, carnivore, omnivore, and detritivore**
Step 2
2 of 6
**Herbivore** are animals that feed on plant materials. They are the ones who consume the primary producers such as plants and algae
Step 3
3 of 6
**Carnivore** is an organism that feeds on the meat or flesh of animals. Such animals rely on their energy and food from animal tissue through hunting or scavenging.
Step 4
4 of 6
**Omnivore** is an organism that can eat and survive by feeding on both plants and animal meat. They are able o digest carbohydrates, fats, proteins and metabolized them to form energy.
Step 5
5 of 6
**Detrivores** are heterotrophic organisms that obtain their food and energy by eating ***detritus** or any organic matter or waste from the dead plants of animals
Step 6
6 of 6
Hence, from the explanation, we can say that
A. Earthworm – Detrivore
B. Bear – Omnivore
C. Cow – Herbivore
D. Snail – Detrivore
E. Owl – Carnivore
F. Human – Omnivore
Exercise 31
Step 1
1 of 1
An example of a simple marine food chain:
1. The phytoplankton is eaten by the zooplankton.
2. Zooplankton is consumed by a herring.
3. The herring is eaten by a bluefin tuna.
4. The tuna is consumed by a shark.
1. The phytoplankton is eaten by the zooplankton.
2. Zooplankton is consumed by a herring.
3. The herring is eaten by a bluefin tuna.
4. The tuna is consumed by a shark.
Nitrogen Cycle in the Marine Ecosystem:
1. Bacteria convert nitrogen gas to ammonia.
2. Other bacteria convert ammonia to nitrates or nitrites.
3. Phytoplankton absorbs either nitrate or ammonium for photosynthesis.
4. Consumers like the zooplankton, herring, and tuna eat phytoplankton and convert nitrogen to make proteins.
5. When a shark dies, decomposers living in the ocean will return nitrogen as ammonia.
Exercise 32
Result
1 of 1
The following are the different food chains found in the food web:
1. Tree, dear, and puma
2. Grass, rabbit, and puma or grass, rabbit, and hawk
3. Grass, mouse and hawk or grass, mouse, and fox
4. Grass, caterpillar, bird, and fox
1. Tree, dear, and puma
2. Grass, rabbit, and puma or grass, rabbit, and hawk
3. Grass, mouse and hawk or grass, mouse, and fox
4. Grass, caterpillar, bird, and fox
unlock