Chapter 24- Population and Sustainability

Question 1

carrying capacity

Answer 1

maximum stable population size of a species that an ecosystem can support

Question 2

environmental resistance

Answer 2

combined effects of limiting factors that prevent the increase of a population

Question 3

Abiotic factors affecting population size

Answer 3

Light availability
Water supply
Water mineral content
Temperature
Space available
Soil pH

Question 4

Biotic factors affecting population size

Answer 4

interactions between organisms
- Interspecific competition (between different species)
- Intraspecific competition (between different members of one species)
- Predation

Question 5

Interspecific competition

Answer 5

competition for the same resources between individuals from different species

Question 6

Intraspecific competition

Answer 6

individuals from the same species compete for the same resources

Question 7

Competitive exclusion

Answer 7

• 2 organisms occupy very similar niches -> comp. can exist between them for resources
• 1 specie may be slightly better adapted to compete than the other, so the other species could starve
• 2nd species would move to a different niche, + may evolve over generations to adapt to its new niche

Question 8

Resource partitioning

Answer 8

• particular resource is divided to satisfy the needs of different feeders
• 2 species are not competing directly but coexist on diff parts

Question 9

Character displacement

Answer 9

• closely related species that inhabit the same geographical region + occupy similar niches differentiate to minimise niche overlap + avoid competitive exclusion

Question 10

Key patterns of predator-prey cycles

Answer 10

• number of predators increases as there is more prey available
• number of prey then decreases as there’re more predators
• number of predators decreases as there’s less prey available
• number of prey increases as there are now fewer predators
• cycle then repeats

Question 11

environmental custodian

Answer 11

• responsibility on humans to manage habitats + species that ensures sustainability + biodiversity for future generations

Question 12

Conservation

Answer 12

• maintain biodiversity and sustainability
• allow managed human activity

Question 13

Preservation

Answer 13

• maintains habitats + populations as they are now
• no usage by humans
• takes place in small geographical areas with no human population + no human intervention
• more focus on conservation

Question 14

Reasons for conserving biological resources

Answer 14

• moral obligation to prevent the manmade loss of biodiversity
• supply of natural resources like wood + paper
• employment
• supply of food
• economic benefits to countries
• protect + value all organisms

Question 15

Ecological reasons

Answer 15

• more diverse ecosystem is better able to survive + adapt to environmental changes/threats

Question 16

Environmental reasons

Answer 16

• need diverse ecosystems = the essential environmental services they provide
• plants absorb carbon dioxide from the atmosphere + help reduce greenhouse effect + climate change
• microorganisms digest + break down organic waste produced by larger organisms
• irrigation + drinking water due to transpiration of plants + their contribution to the water cycle
• fungi + bacteria species = major part of the nutrient cycle that allow nutrients to reenter soil for plant growth
• plants are producers in food webs -> both a direct + indirect energy source for humans through fruit, vegetables and meat