ESS - Unit 2 - Ecosystems and Ecology

Question 1

Habitat

Answer 1

Habitat is the environment in which a species
normally lives.

Question 2

Population

Answer 2

a group of organisms of the same species living in the same area at the same time and which are capable of interbreeding

Question 3

Biotic Factors

Answer 3

the living components of an ecosystem, organisms, their interactions or their waste that directly or indirectly effect another organism.

Question 4

Fundamental Niche

Answer 4

the full range of conditions and resources in which a species can survive and reproduce

Question 5

Realised Niche

Answer 5

Realized niche describes
the actual conditions
and resources in which
a species exists due to
biotic interactions.

Question 6

Carrying Capacity

Answer 6

Carrying capacity is the
maximum number of a
species or ‘load’ that can be
sustainably supported by a
given area.

Question 7

Limiting Factors

Answer 7

factors which slow down growth of a population as it reaches carrying capacity

Question 8

Competition

Answer 8

All the organisms in any ecosystem have some effect on every other
organism in that ecosystem. Also any resource in any ecosystem exists
only in a limited supply. When these two conditions apply jointly,
competition takes place.

Question 9

Population Dynamics

Answer 9

the study of the factors that causes changes to population dynamics

Question 10

Intraspecific Competition

Answer 10

is between members of the same species

Question 11

Interspecific competition

Answer 11

Individuals of different species could be
competing for the same resource. Interspecifc competition may result
in a balance, in which both species share the resource.

Question 12

Predation

Answer 12

When one animal, the predator eats another, the prey

Question 13

Parasitism

Answer 13

relationship between two species in which one species (the parasite) lives on another (the host) gaining its food from it

Question 14

Herbivory

Answer 14

Herbivory is defined as an animal (herbivore) eating a green plant.

Question 15

Mutualism

Answer 15

Mutualism is a relation between two or more species in which all benefit
and none suffer. It is a form of symbiosis (living together) .

Question 16

S - Curve

Answer 16

Starts with exponential growth, after a certain size due to limiting factors it falls. Population stabilises at the carrying capacity.

Question 17

J-Curve

Answer 17

• the population grows exponentially at frst and then, suddenly, collapses.
• the population exceeds the
  carrying capacity on a long-term or continuing basis before the collapse
  occurs (overshoot).
• does not show the gradual slowdown of population growth with increasing population size.
• it is typical of microbes, invertebrates,
  fish and small mammals.

Question 18

What is respiration?

Answer 18

Respiration is the conversion of organic matter into carbon dioxide and water in all living organisms, releasing energy.

Question 19

What is a community?

Answer 19

A community is a group of populations living and interacting with each other in a common habitat (the same place).

Question 20

What is an ecosystem?

Answer 20

An ecosystem is a community and the physical environment it interacts with.

Question 21

Chemosynthetic organisms

Answer 21

they make their own food from
other simple compounds eg ammonia, hydrogen sulphide or
methane, do not require sunlight and are often bacteria found in
deep oceans.

Question 22

Ecological Pyramid

Answer 22

include
pyramids of numbers,
biomass and productivity
and are quantitative models
and are usually measured
or a given area and time.

Question 23

Pyramid of Biomass

Answer 23

biomass contains the biomass (mass of each individual number of individuals) at each trophic level. Biomass is the quantity of
(dry) organic material in an organism, a population, a particular trophic
level or an ecosystem.

Question 24

Pyramid of numbers

Answer 24

shows the number of organisms at each
trophic level in a food chain at one time

Question 25

second law of thermodynamics

Answer 25

States that energy is degraded to lower quality and finally to
heat. The 90% loss of energy in going from one trophic level to the next means there is very little energy available for the next levels.

Question 26

Productivity

Answer 26

is the conversion of energy into
biomass over a given period
of time. It is the rate of
growth or biomass increase
in plants and animals. It is
measured per unit area per
unit time.

Question 27

Gross Productivity

Answer 27

is the total gain in energy or
biomass per unit area per
unit time. It is the biomass
that could be gained by
an organism beore any
deductions.

Question 28

Net Productivity

Answer 28

net productivity (NP) is the
gain in energy or biomass per
unit area per unit time that
remains after deductions
due to respiration.

Question 29

Gross secondary productivity

Answer 29

(GSp) is the total energy / biomass assimilated by consumers and is calculated by subtracting the mass of fecal loss from the mass of food eaten. GSp = food eaten - fecal loss

Question 30

Net Primary Productivity

Answer 30

is the total gain in energy or biomass per unit area per unit time by green plants after allowing for losses to respiration. This is the increase in biomass of the plant how much it grows and is the biomass that is potentially available to consumers (animals) that eat the plant.
NPP = GPP R where
R = respiratory loss

Question 31

Maximum Sustainable Yield

Answer 31

is the largest crop or catch that can
be taken from the stock of a
species (eg a forest, a shoal
of fish) without depleting the stock. Taken away is the increase in production of the stock while leaving the stock to reproduce again. It is often used in managing fisheries.
The MSY is equivalent to the net primary or net secondary productivity of a system.

Question 32

Net Secondary Productivity

Answer 32

calculated by subtracting respiratory losses (R) from GSP.
nSp = GSp - R

Question 33

Transfers and transformations

Answer 33

Matter flows through ecosystems linking them together. This flow of matter involves transfers and transformatios.

Question 34

Biome

Answer 34

is a collection of ecosystems sharing similar climatic conditions.

Question 35

Tricellular model of atmospheric circulation

Answer 35

explains the distribution of precipitation an temperature influencing structure and relative productivity of different terrestrial biomes.

Question 36

Biosphere

Answer 36

is that part of the Earth inhabited
by organisms. It extends from the upper part of the atmosphere down to the deepest parts of the oceans
which support life.

Question 37

Biome Examples

Answer 37

Tropical Rainforest, Deserts, Temperate Grassland, Artic Tundra, Deep ocean

Question 38

Zonation

Answer 38

Changes in community along
an environmental gradient due to factors such as changes in altitude, latitude, tidal level, etc.

Question 39

Succession

Answer 39

How an ecosystem changes over time

Question 40

Primary succession

Answer 40

succession occurs on a bare inorganic surface. It involves the
colonization of newly created land by organisms. It occurs as new land is
either created or uncovered such as river deltas, after volcanic eruptions,
on sand dunes.

Question 41

Secondary succession

Answer 41

Where an already established community is suddenly destroyed, such as following fire or food or even human activity (plowing) an abridged
version of succession occurs.

Question 42

K Strategists

Answer 42

K-strategists, eg humans and other large mammals:
 Have small numbers of offspring.
 Invest large amounts of time and energy in parental care.
 Most offspring survive.
 They are good competitors.
 Population sizes are usually close to the carrying capacity, hence
their name.
 In stable, climax ecosystems, K-strategists out compete r-strategists.

Question 43

R- Strategists

Answer 43

Use lots of energy in the production of vast numbers of eggs.
 No energy is used in raising them after hatching.
 They lay their eggs and leave them  forever.
 They reproduce quickly.
 Are able to colonize new habitats rapidly.
 Make opportunistic use o short-lived resources.
 Because of their last reproductive and growth rates, they may exceed
the carrying capacity, with a population crash as a result. They
predominate in unstable ecosystems.