Ecology

Question 1

Definition of ecology

Answer 1

study of interaction of organisms with one another and with their environment

Question 2

Definititon of habitat

Answer 2

place where an organism lives(condition required for organism’s survival)

Question 3

types of habitat land and marine

Answer 3

land:forest,grassland,desert,rotting logs
marine:freshwater streams,lakes,ocean,coral reef,kelp forest

Question 4

Definition of population

Answer 4

A group of organisms of the same species living in a particular habitat

Question 5

Definition of community

Answer 5

All population of organisms living and interacting with one another in a particular habitat

Question 6

Definition of ecosystem

Answer 6

Living organisms interacting with one another and their abiotic environment

Question 7

Factors in abiotic environment

Answer 7

Light intensity,temperature,amount of water available,pH of water/soil

Question 8

Biotic environment definition

Answer 8

All living organisms that interact with eachother.

Question 9

What is the energy flow in an ecosystem?

Answer 9

Principal source of energy is sun,

plants use light energy from sun to make food using water and carbon dioxide through photosynthesis

Consumers eat the producers and obtain energy by feeding on other organisms

Question 10

what is a food chain

Answer 10

shows transfer of energy from one organism to the next

Question 11

Types of consumers

Answer 11

Hervibore:animal that gets energy by eating only plants

Carnivore:animal that gets energy by eating other animals

Question 12

What is a food web?

Answer 12

network of interconnected food chains,more accurate depiction of habitat as it shows how all organisms are interconnected

Question 13

Limitation of food web/chain?

Answer 13

Does not depict decomposition(what happens to dead plant and animal)

Question 14

what is a trophic level?

Answer 14

each feeding level of a food chain is a trophic level

Question 15

energy flow in food chains?

Answer 15

When one organism consumes another by ingestion the energy from the food gets stored in body or used by organism

Question 16

Efficiency of energy transfer

Answer 16

Only about 10% of energy is transferred from one trophic level to the next

Question 17

What is the energy loss in plants and possible ways energy is lost

Answer 17

plants only transfer about 1-2% of light energy that falls on them

possible ways energy is lost:Wrong wavelength of light,some light passes through leaves,Light energy reflected back to environment,energy released from plant as heat.

Question 18

How energy is gained and possible energy losses in animals

Answer 18

Food digested in alimentary canal and soluble food molecules absorbed into body

Energy losses:Undigested and unabsorbed food,Energy released during respiration as heat,Waste generated from excess nutrients e.g. urine,waste generated in chemical reaction

Question 19

Pyramid of numbers

Answer 19

Shows number of organism in each trophic level,producer bottom,top consumer at top,width drawn to scale,inverted pyramid can exist

Question 20

pyramid of biomass

Answer 20

shows biomass of each trophic level,Biomass=average dry mass of one organismx number of organism in that area,biomass more accurate compared to pyramid of numbers as size is taken into account.CANNOT BE INVERTEd

Question 21

Pyramid of energy

Answer 21

depict amount of energy present in trophic level,cannot be inverted,next trophic level will only have 10% of energy from previous trophic level,most accurate as it reflects actual amount of energy transferred

Question 22

Why trophic levels are no more than 4-5?

Answer 22

energy from producer is insufficient to sustain many consumers as there is huge energy loss in each trophic level

Question 23

Factors affecting pop size

Answer 23

Food supply(more food,more birth,less death,increase in pop),predator prey cycle(predator population increase,prey decrease,less good,predator decreases,usually doesn’t happen in nature as most predators feed on more than one prey)

Question 24

Factors affecting pop size

Answer 24

Disease(increase death rate,reduced birthrate only if it affects mothers,usually with low food supply-not able to fight off infection,more impact of diseases when population is large and dense)

Question 25

Factors affecting pop size

Answer 25

Competition for limited supply of resource such as food,water,space to live

Question 26

Sigmoid population growth curve

Answer 26

Lag phase(organism adapting to environment and growing sufficiently before they can reproduce,takes a while),exponential phase(food supply is abundant,main factor limiting is birth rate,results in rapid increase in numbers),Stationary phase(other factor is limiting such as nutrient,so death rate matches birth rate,pop growth plateaus),logarithmic decline phse(food scarce or toxins reach high concentration and kills organisms)

Only applies to organisms growing in a contained environement,result of changing condition is caused by organism themselves