"Unit1" (10a, 10b, 10c, 10d)

Question 1

Abiotic factors

Answer 1

properties of the environment that are non-living (include temperature, water, nutrient availability and acidity)

Question 2

Biotic factors

Answer 2

properties of the environment that are living (include predator-prey interactions, plant-herbivore interactions, competition for resources and symbiotic relationships)

Question 3

Tolerance range

Answer 3

• The zone in which an organism can survive is called the tolerance range.
• the range of condition within which an organism will thrive, survive or not-stay-alive
  *Every organism has a specific tolerance range for environmental factors (e.g. temperature, oxygen levels, light intensity, etc.)

Question 4

Structural adaptations

Answer 4

evolved modifications to an organism’s physical structure. (Teeth, Body coverings (shells, scales, quills, Insulation)

Question 5

Physiological adaptations

Answer 5

evolved modifications to an organism’s internal functioning or metabolic processes. (Thermoregulation, Making venom, Secreting slime)

Question 6

Behavioural Adaptations

Answer 6

evolved modifications to an organism’s actions. They can be learned or instinctive. (Social behaviour, Behaviour for protection)

Question 7

Thermoregulation

Answer 7

process of maintaining a constant internal body temperature.
*An organism’s survival depends on thermoregulation and maintaining water balance (Organisms obtain water by drinking, eating food and lose water through excretion and evaporative water loss (sweating)

Question 8

2 Structural adaptations for desert environments (animals)

Answer 8

• Insulation
• Surface area to volume ratio (SA:V)

Question 9

Insulation (hot enviro animals)

Answer 9

thin insulating layer is preferable for desert animals

Question 10

Surface area to volume ratio (SA:V)
*high and low (cold enviro animals)

Answer 10

• High SA:V ratio: releases or absorbs a large amount of heat in little time allowing their body temperature to quickly change. (This is beneficial for animals that are able to avoid direct sunlight)
  Low SA:V ratio: releases or absorbs a low amount of heat and their internal body temperature is resistant to change. (This is beneficial for animals if they are exposed to direct sunlight or cannot avoid heat)

Question 11

5 Physiological adaptations for desert environments (animals)

Answer 11

• Metabolic heat
• Surface blood flow
• Increasing/decreasing water input
• Evaporative cooling

Question 12

Metabolic heat

Answer 12

refers to heat generated through biological processes occurring in the body
- two strategies for generating heat: an animal can either be an endotherm or an ectotherm.

Question 13

Surface blood flow

Answer 13

internal temperature rises after activity, blood vessels near the skin dilate and total surface blood flow increases.
- This hot blood releases heat into the enviro cooling the animal down

Question 14

Increasing/decreasing water input

Answer 14

• increasing: Due to low availability of surface water, most desert animals are adapted to survive entirely on the water they consume from food and the water produced during aerobic cellular respiration.
• decreasing: Most desert animals are able to excrete concentrated urine which contains very little water.
  (Have highly complex digestive systems to maximise water absorption from food.
  By excreting highly concentrated wastes, animals conserve water)

Question 15

Evaporative cooling

Answer 15

Animals release huge amounts of heat via the evaporation of water, commonly known as evaporative cooling. (E.g. Sweating and panting)
*Evaporation cools animals down but in dry areas, it can make them lose too much water and get dehydrated

Question 16

2 behavioural adaptations for desert environments (animals)

Answer 16

• Evaders
• Endurers

Question 17

Evaders

Answer 17

generally smaller animals that seek out shade or retreat to a burrow system to avoid hot periods of the day

Question 18

Endurers

Answer 18

generally larger animals that tend towards inactivity during the hottest periods of the day with many digging small pits to sit in, releasing heat into the cooler soil via conduction. (Larger endurers will often seek out shade underneath larger trees)

Question 19

Adapting to the desert: plants

Answer 19

Plants have a number of common structural and physiological adaptations which allow the to live in the harsh conditions present in the desert.

Question 20

In order to survive in hot and dry environments, plants must:

Answer 20

• Decrease their heat intake
• Maximise their water uptake
• Minimise their water loss

Question 21

Decreasing heat uptake

Answer 21

Plants have three common strategies to limit heat absorption:
- Having lightly coloured or reflective leaves (or photosynthetic organs)
- Producing leaves of smaller surface area
- Orienting their leaves vertically to minimise the surface area exposed to the sun.

Question 22

Increasing water uptake

Answer 22

• Plants get the majority of their water by absorbing water through their roots.
• Due to the little rain in the desert, many long-living desert plants have extensive deep root systems capable of reaching groundwater reserves.
• Other plants spread roots horizontally to absorb the maximum amount of surface water during brief periods of rain and store this water for later use.

Question 23

Minimising water loss

Answer 23

• In plants, water loss to the environment can be reduced by reducing the rate of water lost through the stomata during the day.
• Plants can minimise this by reducing their stomatal density
• Guard cells surrounding the stomata can also close the stomata to reduce water loss.
  Rolled and folded leaves can also minimise water loss

Question 24

The most influential factors impacting organisms in cold environments include

Answer 24

• Low temperatures - at low temperatures the reactions required for life slow down or stop.
• Piercing winds - exert strong forces on plants and can dramatically increase heat lost by an organism.
• Low availability of nutrients - a lack of nutrients restricts macromolecule synthesis & overall growth rate.
• Precipitation as snow (and surface water freezing) - make it difficult for organisms to obtain the liquid water required for survival.

Question 25

2 Structural adaptations for cold environments (animals)

Answer 25

• Insulation
• Surface area to volume ratio (SA:V)

Question 26

Insulation (cold enviro animals)

Answer 26

In cold enviros, animals often have a thick insulating layer covering their entire body to minimise heat loss. (This insulation is usually composed of thick fur, plumage or subdermal fat)

Question 27

Surface area to volume ratio (SA:V)
(cold enviro animals)

Answer 27

• By reducing their SA:V ratio, an animal will release heat slowly, increasing the time it takes for body temperature to drop.
• In cold enviros, the more round the organism, the easier it is to maintain a constant body temperature in a cold environment.

Question 28

6 Physiological adaptations for cold environments (animals)

Answer 28

• Endotherms versus ectotherms
• Torpor
• Vasoconstriction
• Countercurrent circulation
• Countercurrent systems to warm blood
• Antifreeze proteins

Question 29

Endotherms versus ectotherms

Answer 29

• Tend to find a greater proportion of endotherms, rather than ectotherms, in cold environments.
• Animals cannot obtain heat from an environment with a lower temperature than their body, so maintaining a stable body temperature via internal metabolic processes is advantageous.

Question 30

Torpor

Answer 30

• A physiological state in which the metabolism of an animal is reduced to conserve energy. (hibernation; in endotherms and brumation; in ectotherms)
• This is beneficial as the reduction in metabolic rate allows the animal to survive on very little food or water and remaining inactive in shelter allows animals to avoid harsh weather.

Question 31

Vasoconstriction

Answer 31

• Occurs when the diameter of small blood vessels in the skin and overall blood flow is reduced.
• When many animals need to conserve heat, blood vessels constrict and heat loss is minimised.

Question 32

Countercurrent circulation

Answer 32

• Uses the heat travelling from the heart to heat cool blood returning from the animal’s periphery, meaning that the core body temperature is not lowered.
• Additionally, this cools the blood heading towards the periphery, so the temperature difference between the periphery and the environment is reduced and less heat is released to the environment.
• The combination of both of these effects means that countercurrent circulation makes it much easier to maintain a stable core body temperature.

Question 33

Countercurrent systems to warm blood

Answer 33

an arrangement of blood vessels in which heat flows from warmer to cooler blood, usually reducing heat loss

Question 34

Antifreeze proteins

Answer 34

• Many organisms are able to make antifreeze proteins in winter to prevent the formation of large ice crystals in the body, enabling water to remain liquid at lower temperatures.
  (For example, frogs freeze solid in winter but the ice doesn’t penetrate their cells because of antifreeze proteins)

Question 35

4 behavioural adaptations for cold environments (animals)

Answer 35

• Reducing exposed surface area
• Huddling
• Seeking shelter
• Migrating to a warmer climate

Question 36

Reducing exposed surface area

Answer 36

• Objects with lower surface area to volume ratios release less heat.
• Many animals will reduce their surface area to volume ratio by hiding or protecting their peripherals as temperatures drop.
  (For example, in response to the cold many animals will curl up and birds may stand on only one leg)

Question 37

Huddling

Answer 37

• Emperor penguins can be seen huddling during the Antarctic winter, where temperatures often reach as low as -40°C.
• Huddling allows animals to artificially decrease their individual surface area to volume ratio, decreasing the amount of heat released into the environment.

Question 38

Seeking shelter

Answer 38

• By seeking shelter, animals can surround themselves in a stable microclimate with little or no wind and more forgiving temperatures.
• Animal shelters typically include underground burrows, dens or rocky outcrops.

Question 39

Migrating to a warmer climate

Answer 39

• During cold winter months, many animals will migrate from one area to another location that has a more moderate climate and more readily available resources.
• Warmer climates are also easier for breeding and raising newborns.

Question 40

Adapting to the desert: plants

Answer 40

Plants have a number of common structural and physiological adaptations which allow the to live in the harsh conditions present in a cold climate.

Question 41

In order to survive in cold environments, plants must

Answer 41

• Modifications to the chemical composition of the cell membrane
• Increasing solute concentration
• Antifreeze proteins
• Seed dormancy
• Deciduous trees

Question 42

Modifications to the chemical composition of the cell membrane

Answer 42

increases functioning in low temperatures

Question 43

Increasing solute concentration

Answer 43

lowers the freezing point and increases a plant cell’s resistance to freezing

Question 44

Antifreeze proteins

Answer 44

disrupt the formation of ice crystals within the cell, enabling water to remain liquid at lower temperatures

Question 45

Seed dormancy

Answer 45

• A dormant seed is unable to germinate during a specific time under certain environmental conditions.
• Seed dormancy is a trait of many cold-adapted plants, where seeds are dispersed before winter months and remain dormant until warmer spring weather.

Question 46

Deciduous trees

Answer 46

A deciduous tree is a tree that seasonally drops all of its leaves at once to avoid harsh conditions

Question 47

Ecosystems include three essential parts

Answer 47

• A living community
• The non-living surroundings
• interactions within the living community and between the community and the non-living surroundings.

Question 48

Five levels of ecological organisation

Answer 48

• Cell: individual cells of a larger organism.
• Organism: an individual living thing, such as an animal, plant or single-celled form of life.
• Population: a group of organisms of the same species living in the same geographical region.
• Community: interacting populations of different species in the same geographical region.
• Ecosystem: multiple communities interacting with one another and their physical environment.
  *Ecosystems are made up of both biotic and abiotic factors and contain many individual and population interactions, as well as the flow of energy/nutrients between organisms.

Question 49

population size (of a species)

Answer 49

total number of members within any given population.

Question 50

carrying capacity

Answer 50

limits as to how many individuals an environment can support and sustain

Question 51

Factors that alter a population’s size include

Answer 51

*Population size can increase and decrease over time.

Factors:
- Births
- Deaths
- Immigration (migration of individuals into a population)
- Emigration (migration of individuals out of a population)

Question 52

population growth model

Answer 52

Ni+1 = Ni + births − deaths + immigration − emigration

*where:
Ni+1 = future population size
Ni = initial population size

Question 53

Population distribution (of a species)

Answer 53

range of geographical areas that members of a population can be found in.
*The population distribution of a species is influenced by a whole range of factors and can be uniform, random or clumped.

Question 54

population density (of a species)

Answer 54

number of individuals found in a given area, such as individuals per square kilometer

Question 55

2 Factors impacting population size and definition

Answer 55

• Density-independent factors: Environmental factors that affect population growth but are not affected by population density.
• Density-dependent factors: Environmental factors that affect population growth and become stronger as population density increases.

Question 56

Several different types of symbiotic interactions between organisms exist, including

Answer 56

Mutualism
Commensalism
Predation
Parasitism
Amensalism
Competition

Question 57

Mutualism definition

Answer 57

(+/+)
describes interactions between two organisms of different species where both parties experience some overall benefit
(eg: Humans and bacteria, bacteria living in our gut get nutrients from us while we gain protection from pathogens)

Question 58

Commensalism

Answer 58

(+/0)
describes interactions between two organisms of different species where one organism gains some benefit while the other experiences no significant benefit or harm
(eg: clownfish obtains shelter & food scraps from the anemone but the anemone experiences no significant benefit from the presence of the clownfish)

Question 59

Predation

Answer 59

(+/-)
describes interactions between different species where one organism (the predator) hunts and kills another (the prey) for food. Predator receives the benefit of obtaining food, while the prey is killed and eaten
(eg: )

Question 60

Parasitism

Answer 60

(+/-)
describes interactions between two or more organisms of different species where one organism (the parasite) obtains nutrients at the expense of another organism (the host)
(eg: )

Question 61

Amensalism

Answer 61

(0/-)
describes interactions between two or more organisms of different species where one organism experiences some negative effect while the other experiences neither a beneficial nor negative effect
(eg: cattle, sheep and deer, which trample grasses and small shrubs while receiving no benefit or harm)

Question 62

Competition

Answer 62

(-/-)
describes interactions between two or more organisms competing for the same pool of resources. never a ‘winner’ in competition, rather there are two individuals trying to ‘outcompete’ one another
(eg: weeds growing in a vegetable garden compete with vegetables for water and nutrients in the soil)

Question 63

IntERspecific competition

Answer 63

competition for resources between members of different species (e.g. weeds and vegetables competing for water and nutrients in a garden).

Question 64

IntrAspecific competition

Answer 64

competition for resources between members of the same species (e.g. two male kangaroos fighting to establish dominance and win over a female mate)

Question 65

keystone species

Answer 65

play a much larger role in maintaining ecosystem structure and composition than other species.

Question 66

keystone species features

Answer 66

• removing a keystone species typically has a larger effect than removal of other species.
• Identifying keystone species is tricky since removing any species affects the ecosystem. Yet, they typically play consistent roles within an ecosystem.
• Two common roles that keystone species fulfil are: apex predators and ecosystem engineers.

Question 67

apex predator

Answer 67

a predator that has no natural predators and is at the top of its food chain.
(eg: great white sharks are apex predators that have an immense impact on their ecosystem and are therefore classified as a keystone species)
*more info on notes

Question 68

Ecosystem engineers

Answer 68

interact with and significantly alter the physical environment of their ecosystem.
(eg: the greater bilby is an ecosystem engineer and keystone species within the Australian environment)
*more info on notes

Question 69

Indigenous Australian Ways of Knowing

Answer 69

emphasise the connections and relationships within systems and between nature and people, aiming for a holistic understanding of the world.
*MORE INFO IN NOTES

Question 70

Country

Answer 70

an area that is traditionally owned and looked after by an Aboriginal language group or community, or by certain people within that group.
*MORE INFO IN NOTES

Question 71

Indigenous understanding of adaptations

Answer 71

• Indigenous Australians have deep cultural knowledge of how environmental adaptations aid species survival.
• Can be seen in Indigenous history by examining the Indigenous practice of cultural fire management.
• To survive in this arid environment, Aboriginal Australians had to survive these adaptations and learn to use fire to manage and stimulate plant growth.
  *MORE INFO IN NOTES

Question 72

They (aborigionals) used fire in a variety of ways, including to

Answer 72

• Clear shrubs from grasslands and woodlands
• Promote various species of plants
• Break up Country and reduce the intensity and extent of wildfires

Question 73

Cultural fire management

Answer 73

• Aboriginal managers would walk Country and were able to see where fire was needed, using it appropriately to address any issues they discovered.
• The type of findings that might have triggered a decision to burn include the presence of:
  . Long, dry grass
  . A large amount of leaf litter on the ground
  . Dead standing shrubs
  . Fire hazards around camps and paths
• Aboriginal-managed fires were smaller, more frequent, and less damaging, often called ‘cool burns.’
• Cool burns led to less intense bushfires, preserving crucial ecosystem components like habitat trees and hollows.
• Also results in a fire mosaic
• The fire mosaic made the environment safer from intense bushfires, enabling the growth of diverse plants and animal foods.
  *MORE INFO IN NOTES

Question 74

Indigenous understanding of interdependencies

Answer 74

• Interdependencies between species within an ecosystem are well understood by Indigenous Australians. (An example is the mutualistic relationship between quandong trees & emus)
  *MORE INFO IN NOTES