QUESTIONS (A): 1. Define environment. 2. Describe, in detail, the niche of a human. 3. How is natural selection related to the concept of niche? 4. List five predators and their prey organisms. 5. How is an ecosystem different from a community? QUESTIONS (B): 6. Humans raising cattle for food is what kind of relationship? 7. Give examples of organisms that are herbivores, and omnivores. 8. What are some different trophic levels in an ecosystem? 9. Describe the carbon cycles, the nitrogen cycles, and the phosphorus cycles. 10. Analyze an aquarium as an ecosystem. Identify the major abiotic and biotic factors. List members of the producer, primary consumer, secondary consumer, and decomposer trophic levels.

1. Group 12:
1. PHAI MINEA [Leader: 0966153104] (ID: 2119055)
2. LAO SOKKEANG [0966973633] (ID: 2119639)
3. OL KIMMEY [098661176] (ID: 2120522)
4. RITH CHHAINGIM [0969071860] (ID: 2121245)
5. OSOTH RATANADAVID [086455494] (ID: 2119875)

2. REVIEW QEUSTIONS
QUESTIONS (A):
1. Define environment.
2. Describe, in detail, the niche of a human.
3. How is natural selection related to the concept of niche?
4. List five predators and their prey organisms.
5. How is an ecosystem different from a community?
QUESTIONS (B):
6. Humans raising cattle for food is what kind of relationship?
7. Give examples of organisms that are herbivores, and omnivores.
8. What are some different trophic levels in an ecosystem?
9. Describe the carbon cycles, the nitrogen cycles, and the phosphorus cycles.
10. Analyze an aquarium as an ecosystem. Identify the major abiotic and biotic factors.
List members of the producer, primary consumer, secondary consumer, and
decomposer trophic levels.
ANSWER
PART(A):
1. Define environment.
Answer 1:
Everything that affects an organism during its lifetime is collectively known as its
environment. The environment of an organism can be divided into biotic (living) and abiotic
(non-living) components.
o Living (biotic factors) of an organism's environment include all forms of life with
which it interacts.
o Nonliving (abiotic factors) : energy, nonliving matter, and processes that involve the
interactions of nonliving matter and energy.
2. Describe, in detail, the niche of a human.
Answer 2:
The role organism plays in its environment is known as its niche. The niche of a
species is the result of natural selection directing the adaptation of the species to a specific set
of environmental conditions. The ecological niche of an organism is a complex set of
interactions between an organism and its surroundings, which includes all of the ways an

3. organism influences its surroundings as well as of the ways the organism is affected by its
environment.
Example: Human use the plant for food, need the air for breathing, need sunlight for
growth and strong.
3. How is natural selection related to the concept of niche?
Answer 3:
Natural selection is the process whereby successful organisms pass on the
characteristics which made them successful to their offspring. In this way, each organism is
finely tuned to a particular habitat and niche, and unfit individuals are removed from the
population.
4. List five predators and their prey organisms.
Answer 4:
List five predators and their prey organisms
 lion and zebra
 bear and fish
 fox and rabbit
 snake and rat
 tiger and deer.
5. How is an ecosystem different from a community?
Answer 5:
An ecosystem different from a community:
 An ecosystem is defined space in which interactions take place between a
community, with all its complex interrelationships, and the physical
environment. Some ecosystems, such as grasslands and certain kinds of
forests, are shaped by periodic fires. The kind of soil and the amount of
moisture also influence the kinds of organisms found in an area.
 A community is an assemblage of all the interacting populations of different
species of organisms in an area. Some species play minor roles, while others
play major roles, but all are part of the community. For example, the grasses
of the prairie have a major role since they carry on photosynthesis and provide
food and shelter for the animals that live in the area.

4. PART(B):
6. Humans raising cattle for food is what kind of relationship?
Answer 6:
Humans raising cattle for food is technically a form of predation. Humans are
secondary consumers feeding on the cattle which are primary consumers feeding on the
plants which are primary producers. It could be argued however, that it is a type of
mutualistic relationship in which both populations benefit, because the cattle has been so
changed that it cannot survive without human interaction.
7. Give examples of organisms that are herbivores, and omnivores.
Answer 7:
 Examples of herbivores include seed-eating birds, deer, rabbits, and
zooplankton.
 Examples of camivores include wolves, falcons, and sharks. Examples of
omnivores include humans, bears, and raccoons.
8. What are some different trophic levels in an ecosystem?
Answer 8:
Trophic levels in an ecosystem include producers, herbivores, carnivores, omnivores,
and decomposers.
9. Describe the carbon cycles, the nitrogen cycles, and the phosphorus cycles.
Answer 9:
Describe the carbon cycles, the nitrogen cycles, and the phosphorus cycles:
 The carbon cycle is nature's way of reusing carbon atoms, which travel from
the atmosphere into organisms in the Earth and then back into the atmosphere
over and over again. Most carbon is stored in rocks and sediments, while the
rest is stored in the ocean, atmosphere, and living organisms.
 Nitrogen Cycle is a biogeochemical process through which nitrogen is
converted into many forms, consecutively passing from the atmosphere to the
soil to organism and back into the atmosphere. It involves several processes
such as nitrogen fixation, nitrification, denitrification, decay and putrefaction.
 The phosphorus cycle is the process by which phosphorus moves through the
lithosphere, hydrosphere, and biosphere. Phosphorus is essential for plant and
animal growth, as well as the health of microbes inhabiting the soil, but is
gradually depleted from the soil over time.
10. Analyze an aquarium as an ecosystem. Identify the major abiotic and biotic factors.
List members of the producer, primary consumer, secondary consumer, and
decomposer trophic levels.
Answer 10:

5. Analyze an aquarium as an ecosystem. Identify the major abiotic and biotic factors.
List members of the producer, primary consumer, secondary consumer, and decomposer
trophic levels:
• Analyze an aquarium as an ecosystem.
 Aquarium is a building where people go to look at fish and other water
animals. Analyze an aquarium as an ecosystem is light, temperature,
salinity, dissolved oxygen, and nutrients.
• Identify the major abiotic and biotic factors.
 Biotic Factors (living) of an organism's environment include all forms
of life with which it interacts.
 Abiotic Factors (nonliving) can be organized into several categories:
energy, nonliving matter, and processes that involve the interactions of
nonliving matter and energy.
• List members of the producer, primary consumer, secondary consumer,and
decomposer trophic levels.
 Producer
o Grass, algae, phytoplankton, tree, flower, fern, or moss.
 Primary consumer
o Grasshopper, mosquito larva, dragontly larva, or zooplankton.
 Secondary consumer
o Rat, dragonfly larva, or fish.
 Decomposer
o Fungi, bacteria, some insects, and worms.