Unit 2

Question 1

species

Answer 1

group of organisms sharing common characteristics that interbreed and produce fertile offspring

Question 2

habitat

Answer 2

environment in which a species normally lives

Question 3

niche

Answer 3

particular set of abiotic and biotic conditions and resources to which an organism or population responds

Question 4

population

Answer 4

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

Question 5

parasitism

Answer 5

the host provides a habitat and food for the bacteria, but in return, the bacteria cause disease in the host

Question 6

competition

Answer 6

a common demand by two or more organisms upon a limited supply of a resource

Question 7

predation

Answer 7

one species feeds on another which enhances fitness of predator but reduces fitness of prey

Question 8

herbivory

Answer 8

the act of eating plants

Question 9

mutualism

Answer 9

a type of symbiotic relationship in which both species benefit from the relationship

Question 10

different interactions between organisms

Answer 10

the interactions should be understood in terms the influences each species has on the population dynamics of others, and upon the carrying capacity of others’ environment.
eg: mutualism, parasitism, predation, competition

Question 11

difference between fundamental and realised niche

Answer 11

fundamental: full range of conditions and resources in which a species could survive and reproduce
realised: actual range of conditions and resources in which a species exists due to its biotic interactions such as competition and predation

Question 12

difference between abiotic and biotic factors

Answer 12

Biotic factors are living things within an ecosystem; such as plants, animals, and bacteria, while abiotic are non-living components; such as water, soil and atmosphere

Question 13

what does an s curve represent

Answer 13

In an environment where resources become limited, populations exhibit a pattern of growth called logistic growth. A logistic growth pattern (S curve) occurs when environmental pressures slow the rate of growth.

Question 14

what does a j curve represent

Answer 14

J curve can be defined as the j shaped growth curve that graphically represents a situation in a new environment where the population density of an organism increases at an exponential rate.

Question 15

the impact of limiting factors on population growth

Answer 15

slowing of population growth as it approaches the carrying capacity of a system

Question 16

carrying capacity

Answer 16

the maximum number of individuals of a given species that an area’s resources can sustain indefinitely without significantly depleting or degrading those resources.

Question 17

community

Answer 17

group of populations living and interacting with each other in a common habitat

Question 18

ecosystem

Answer 18

is a community and the physical environment it interacts with

Question 19

inputs and outputs of photosynthesis

Answer 19

inputs – light energy, carbon dioxide, water
outputs – glucose, oxygen

Question 20

inputs and outputs of respiration

Answer 20

inputs – glucose, oxygen outputs – carbon dioxide, energy, water.

Question 21

first law of thermodynamics and how it is illustrated in an ecosystem

Answer 21

Energy cannot be created or destroyed. It is just converted from one form to another.
is illustrated by the flow of energy and matter (photosynthesis)

Question 22

second law of thermodynamics and how it is illustrated in an ecosystem

Answer 22

states that in any closed system, the amount of usable energy decreases over time
is illustrated by the flow of energy from one trophic level to another

Question 23

identify producers, consumers and various trophic levels in a food chain

Answer 23

Producers: - autotrophs (green plants)
- chemosynthetic organisms
Consumers (herbivores, carnivores, omnivores, detritivores and decomposers)

Question 24

state the source of energy for all food chains

Answer 24

SUN

Question 25

the difference between chemosynthetic and photosynthetic organisms

Answer 25

photosynthesis is powered by sunlight while chemosynthesis runs on chemical energy

Question 26

bioaccumulation

Answer 26

build up of persistent/non-biodegradable pollutants within an organism or a trophic level because they cannot be broken down

Question 27

biomagnification

Answer 27

increase in concentration of persistent or non biodegradable pollutants along a food chain

Question 28

examples of toxins which accumulate along a food chain

Answer 28

DDT and mercury due to the decrease of biomass and energy

Question 29

explain when an inverted pyramid of numbers would be seen

Answer 29

when individuals at lower trophic levels are relatively large

Question 30

explain the impact of a persistent pollutant in an ecosystem

Answer 30

accumulate and magnify in living organisms through the food chain, and are toxic to both humans and wildlife.

Question 31

explain why not all solar radiation becomes available to ecosystems

Answer 31

as solar radiation enters the Earth's atmosphere some energy becomes unavailable for ecosystems as the energy is absorbed by inorganic matter or reflected back into the atmosphere

Question 32

state different pathways of energy through an ecosystem

Answer 32

- conversion of light energy to chemical energy - transfer of chemical energy from one trophic level to another with varying efficiencies - overall conversion of ultraviolet and visible light to heat energy by an ecosystem - re-radiation of heat energy to the atmosphere

Question 33

Define GPP, NPP, GSP and NSP

Answer 33

GPP= Gross Primary Productivity NPP= Net Primary Productivity GSP= Gross Secondary Productivity NSP= Net Secondary Productivity

Question 34

Calculate NPP, GSP and NSP

Answer 34

NPP= GPP-R GSP= food eaten - fecal loss NSP= GSP-R

Question 35

define maximum sustainable yield

Answer 35

equivalent to the net primary or net secondary productivity of a system

Question 36

explain the impact of human activity on sinks and flows in the carbon and nitrogen cycles

Answer 36

In the carbon cycle, increased emissions of carbon dioxide from fossil fuel burning, deforestation, and other activities has led to an increase in atmospheric carbon dioxide levels, resulting in higher temperatures and more extreme weather events. In the nitrogen cycle, human activities such as agriculture and industry have led to an increase in the amount of nitrous oxide released into the atmosphere, leading to smog and other environmental problems.

Question 37

biomes

Answer 37

collections of ecosystems sharing similar climatic conditions which can be grouped into five major classes - aquatic, first, grassland, desert, and tundra

Question 38

state factors which impact biome distribution

Answer 38

Temperature range, soil type, and the amount of light and water

Question 39

Briefly state the influence of the tricellular model on biome distribution

Answer 39

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

Question 40

zonation

Answer 40

refers to changes in community along an environmental gradient

Question 41

state factors which cause zonation

Answer 41

changes in altitude, latitude, tidal level, or distance from shore

Question 42

succession

Answer 42

process of change over time in an ecosystem involving pioneer, intermediate and climax communities

Question 43

Explain the stages in primary succession using key terminology (pioneers, intermediate communities, climax communities etc)

Answer 43

Primary succession is the gradual process of ecosystem development which occurs when a new environment is colonized by life. It has four distinct stages: 1) Pioneer species colonize the area and begin to break down rocks, creating soil; 2) Intermediate communities develop, increasing biodiversity; 3) Climax communities are established, marked by increased diversity and stability; 4) Succession is complete when a mature, stable ecosystem is established.

Question 44

Explain the changes that occur during succession

Answer 44

during succession the patterns of energy flow, gross and net productivity, diversity and mineral cycling change over time

Question 45

r and k strategist species

Answer 45

have reproductive strategies that are better adapted to pioneer and climax communities respectively

Question 46

Explain the difference between r and k selected species

Answer 46

R-selected species are species that reproduce quickly and have short life spans. They tend to produce large numbers of offspring but do not invest much in the care of each individual offspring. K-selected species, on the other hand, reproduce slowly and have longer life spans. They produce fewer offspring but invest more resources in each individual, such as providing parental care or teaching the offspring necessary skills for survival.

Question 47

Explain the impact of succession on GPP and NPP

Answer 47

Primary succession has a significant impact on Gross Primary Productivity (GPP) and Net Primary Productivity (NPP). As new species colonize an area, GPP and NPP increase as the environment becomes more hospitable to plants and other organisms. Over time, GPP and NPP reach a peak as the environment reaches the climax community stage. After this point, GPP and NPP may decrease slightly as the environment becomes more stable, although they typically remain at high levels.

Question 48

Explain when secondary succession may occur

Answer 48

where natural communities develop in an area that was earlier occupied by living organisms that were somehow lost. It begins in areas where natural biotic communities have been destroyed such as in abandoned farm lands, deforested lands, flooded lands, burned forests, etc.

Question 49

Compare distribution, structure, biodiversity and productivity of 2 contrasting biomes

Answer 49

Two contrasting biomes are the tropical rainforest and the desert. The tropical rainforest is characterized by high levels of precipitation, warm temperatures, and a high diversity of plants and animals. In contrast, the desert is characterized by low levels of precipitation, extreme temperatures, and relatively low biodiversity. The tropical rainforest is more productive than the desert due to its higher levels of rainfall, leading to a greater availability of resources for plants and animals. Additionally, the rainforest has a more complex structure, with multiple layers of vegetation, while the desert has a simpler, more uniform structure. Finally, the tropical rainforest is much more biodiverse than the desert, with a wide variety of plants and animals adapted to their environment.

Question 50

Explain why sampling would be used

Question 51

Explain why measurements in sampling should be repeated

Question 52

Explain how to use named equipment to measure at least 3 different abiotic factors

Question 53

Evaluate at least 3 pieces of equipment used to measure abiotic factors

Question 54

Explain methods for sampling motile organisms

Question 55

Explain methods for calculating biomass and productivity of ecosystems and evaluate these

Question 56

Explain the use of transects and quadrats

Question 57

Understand the use of the Lincoln index and be able to calculate it and evaluate its use

Question 58

Understand the use of Simpsons Diversity Index and be able to calculate it and evaluate its use