Module 3: Biological Diversity

Question 1

Abiotic Factors

Answer 1

The non-living components of an environment (eg. temp, light, chemical components (pH, water & gases))

Question 2

Biotic Factors

Answer 2

The living components of an environment (eg. bacteria, fungi animals & plants)

Question 3

Selection Pressures

Answer 3

All the biotic & abiotic factors in an organism’s environment that effect the individuals behaviour, survival & reproduction
Selection pressures drive evolutionary change

Question 4

Abiotic Selection Pressures

Answer 4

• Light
• Temp
• Chemical components
• Weather
• Shelter
• Water
• Topography

Question 5

Biotic Selection Pressures

Answer 5

• Predation
• Disease
• Competition for food
• Competition for mates

Question 6

Organising Environments

Answer 6

1. Individual - single organism
2. Population - group of same species in defined area
3. Community - ecological group that interacts (diff. species)
4. Ecosystem - communities interacting with one another & physical surroundings

Question 7

Biosphere

Answer 7

Sum of all ecosystems on Earth
Including;
Oceans, rivers & lakes (biosphere)
Soil & rocks (lithosphere)
Air (atmosphere)

Question 8

Biome

Answer 8

A group of all communities that have similar structures & habitats over a large area

Question 9

Habitat

Answer 9

Type of place where an organism lives
Used for shelter, obtaining resources, breeding & raising offspring

Question 10

Microhabitat

Answer 10

Within a habitat are smaller areas known as microhabitats
Have slightly different environment to overall habitat

Question 11

Keystone Species

Answer 11

Play a crucial role in maintaining the structure of an ecosystem

Question 12

Population Distribution

Answer 12

All the places where a species is found
Three basic patterns of distribution:
- Random
- Uniform
- Clumped

Question 13

Population Density

Answer 13

The no. of individuals per unit of area or volume

Question 14

Biomass

Answer 14

If it is difficult to count individuals, the size of a population can be measured by biomass (measured in kg per unit area)

Question 15

Population Growth

Answer 15

The size of a population can be affected by:
- Births or germinations (natality)
- Deaths (mortality)
- Immigration (movement into population)
- Emigration (movement out of population)

Question 16

Exponential Population Growth

Answer 16

When populations are not limited by resources, predators or diseases - they can experience continual, unlimited growth known as exponential growth
- J-shaped curve on graph

Question 17

Population Explosions

Answer 17

Occur if populations grow exponentially over a long period of time
Those that have rapid rates of reproduction, are readily adaptable to new conditions & have no limiting factors.

Question 18

Adaptation

Answer 18

The development of specific features of an organism that enable them to survive & reproduce in a specific environment
Arise in response to specific abiotic & biotic factors
Is an evolutionary response driven by natural selection

Question 19

Adaptations allow organisms to…

Answer 19

• Access resources
• Attract mates
• Avoid predation
• Communicate

Question 20

Structural Adaptations

Answer 20

The physical features of an organism that allow it to be better suited to its environment.
- size
- shape
- colour
- external factors

Question 21

Physiological Adaptations

Answer 21

The internal bodily functions of an organism that help it to be better suited to its environment (chemical processes)
Eg. panting, producing venom, functional proteins (enzymes)

Question 22

Behavioural Adaptations

Answer 22

The actions that an organism takes to improve its ability to survive in its environment
Eg. seeking shade, huddling, migration