PCA: Laws and Regulations Exam Questions
and Answers with Verified Solutions | Latest
Updated 2026
Natural Selection process that results in the adaptation of
an organism to its environment by means
of selectively reproducing changes in its
genotype, or genetic constitution.
Ecological Niche how a species interacts with, and lives in,
its habitat. Ecological niches have
specific characteristics, such as
availability of nutrients, temperature,
terrain, sunlight and predators, which
dictate how, and how well, a species
survives and reproduces.
Habitat ecological or environmental area that is
inhabited by a particular species of
animal, plant or other type of organism.
Population Density the number of individuals of a species in
a defined area. Can be varied; increase
or decrease over time.
Ecotype a genetically distinct geographic variety,
population or race within a species,
which is genotypically adapted to
specific environmental conditions.
,Species Diversity as the number of species and abundance
of each species that live in a particular
location.
Population vs Community of Population consist only a single species
organisms while a community consist of all the
populations of plants, animals, and
organisms that share and interact with
one another.
Factors affecting population Weather, water and nutrient availability,
regulation predators, competitors, disease, or food
availability.
Factors b/w density Dependent - species are dependent on
dependent and independent resources and when populations are high
= competition, predation, and disease can
limit pop. growth(biotic). Independent -
species population are independent and
include disturbances such as floods,
drought, fires(abiotic).
(3) types of pop. dispersal immigration, emigration, and migration
patterns
How does energy flow Light is captured by plants and converted
through an ecosystem? to carbohydrates that the plant uses.
Other organisms use and convert this
chemical energy to various forms through
the food chain. At each step, this energy
is assimilated and used by organism and
rat is released as waste.
, Describe a biogeochemical plants take up nutrients from the soil and
cycle in an ecosystem. convert them into biologically useful
compounds. many organisms take the
nutrients into their bodies by feeding on
these plants. Nutrients cycles; nitrogen,
carbon, sulfur, etc.
Nitrogen cycle nitrogen moves from the air into the
ground through organism, plants, and
animals via leaching, decomp. of OM,
and mineralization. N returns to the
atmosphere through volatilization and
denitrification by bacteria.
Abiotic components? Soil - Plant medium, reservoir for
Examples nutrients and cycling, and site of
decomposition. Foundation upon which
all terrestrial life depends.
Water - Factor in weathering, leaching,
and erosion, and allows the intro and loss
of nutrients from the ecosystem.
Light - Provides the predominant source
of energy in an ecosystem.
Temp, climate, gases.
Different trophic levels? Primary producers(plants/autotrophs),
primary consumer(insects), secondary
consumers(insect predators),
Food Web? More complex than food chain. At every
level of a food chain, many organisms
may feed on a single organism so that
feeding and energy flow forms complex
food webs.
and Answers with Verified Solutions | Latest
Updated 2026
Natural Selection process that results in the adaptation of
an organism to its environment by means
of selectively reproducing changes in its
genotype, or genetic constitution.
Ecological Niche how a species interacts with, and lives in,
its habitat. Ecological niches have
specific characteristics, such as
availability of nutrients, temperature,
terrain, sunlight and predators, which
dictate how, and how well, a species
survives and reproduces.
Habitat ecological or environmental area that is
inhabited by a particular species of
animal, plant or other type of organism.
Population Density the number of individuals of a species in
a defined area. Can be varied; increase
or decrease over time.
Ecotype a genetically distinct geographic variety,
population or race within a species,
which is genotypically adapted to
specific environmental conditions.
,Species Diversity as the number of species and abundance
of each species that live in a particular
location.
Population vs Community of Population consist only a single species
organisms while a community consist of all the
populations of plants, animals, and
organisms that share and interact with
one another.
Factors affecting population Weather, water and nutrient availability,
regulation predators, competitors, disease, or food
availability.
Factors b/w density Dependent - species are dependent on
dependent and independent resources and when populations are high
= competition, predation, and disease can
limit pop. growth(biotic). Independent -
species population are independent and
include disturbances such as floods,
drought, fires(abiotic).
(3) types of pop. dispersal immigration, emigration, and migration
patterns
How does energy flow Light is captured by plants and converted
through an ecosystem? to carbohydrates that the plant uses.
Other organisms use and convert this
chemical energy to various forms through
the food chain. At each step, this energy
is assimilated and used by organism and
rat is released as waste.
, Describe a biogeochemical plants take up nutrients from the soil and
cycle in an ecosystem. convert them into biologically useful
compounds. many organisms take the
nutrients into their bodies by feeding on
these plants. Nutrients cycles; nitrogen,
carbon, sulfur, etc.
Nitrogen cycle nitrogen moves from the air into the
ground through organism, plants, and
animals via leaching, decomp. of OM,
and mineralization. N returns to the
atmosphere through volatilization and
denitrification by bacteria.
Abiotic components? Soil - Plant medium, reservoir for
Examples nutrients and cycling, and site of
decomposition. Foundation upon which
all terrestrial life depends.
Water - Factor in weathering, leaching,
and erosion, and allows the intro and loss
of nutrients from the ecosystem.
Light - Provides the predominant source
of energy in an ecosystem.
Temp, climate, gases.
Different trophic levels? Primary producers(plants/autotrophs),
primary consumer(insects), secondary
consumers(insect predators),
Food Web? More complex than food chain. At every
level of a food chain, many organisms
may feed on a single organism so that
feeding and energy flow forms complex
food webs.
