2.1 species and populations

Question 1

species

Answer 1

group of organisms with common characteristics that can interbreed to produce fertile offspring

Question 2

population

Answer 2

group of individuals of the same species living in the same area at the same time

Question 3

habitat

Answer 3

environment in which a species usually lives

Question 4

niche

Answer 4

• role an organism plays + position it holds in the environment
• includes all interactions the organism has with the abiotic and biotic environment

Question 5

fundamental niche

Answer 5

describes the environmental conditions under which a species can live

Question 6

realised niche

Answer 6

actual conditions in which a species exists due to biotic interactions

Question 7

abiotic + examples

Answer 7

• non-living, physical factors that influence organisms and ecosystems
• temp, sunlight, water, ph, salinity

Question 8

biotic

Answer 8

• interactions between the organisms (producers, consumers, decomposers)

Question 9

j curve

Answer 9

• exponential pop. growth
• are not sustained in the real world (may occur for short periods but a crash is inevitable)

Question 10

s curve

Answer 10

• logistic pop. growth
• pop. growth rate accelerates then slows down when it reaches max carrying capacity

Question 11

predation

Answer 11

one organism hunts and kills another (wolves hunting rabbits)

Question 12

herbivory

Answer 12

animals that consume plants (elephants: bark, leaves, roots, grass)

Question 13

mutualism

Answer 13

two organisms of different species co-existing (bacteria + cows, cows have better digested food)

Question 14

parasitism

Answer 14

organism takes nutrients from another (host) without killing them (lice, ticks)

Question 15

disease

Answer 15

departure of normal state of functioning (ebola virus)

Question 16

competition

Answer 16

competition of resources in a limited supply
- inter-species: dif. species (lions and hyenas)
- intra-species: same species (trees)

Question 17

population control

Answer 17

happens via negative feedback, like wolves and rabbits
- increase in rabbit pop. –> more food for wolves –> increase in wolf pop. –> decrease in rabbit pop. –> decrease in wolf pop.

Question 18

ecological systems: predictable or chaotic?

Answer 18

chaotic
- external factors (weather, climate change)
- hard to predict impact of human activities

Question 19

density independant factors impacting population growth

Answer 19

abiotic in nature + impact pop. no matter how large they are
- climate, weather, natural disasters

Question 20

density dependant factors impacting population growth

Answer 20

biotic interactions + impact they have varies on how dense a population is (denser the pop. the greater their impact)