Exam term 1

Question 1

What do the arrows stand for in a food chain/web?

Answer 1

“is eaten by”

Question 2

What are trophic levels?

Answer 2

The levels of consumers in an ecosystem

Question 3

What is the difference between an autotroph and heterotroph?

Answer 3

Heterotrophs get energy from other organisms, autotrophs make their own energy

Question 4

What is productivity?

Answer 4

The amount of energy present at each trophic level

Question 5

What is the equation for photosynthesis?

Answer 5

6CO2 + 12H2O > C6H12O6 + 6O2 + 6H2O

Question 6

What is the difference between gross and net primary productivity?

Answer 6

Gross is the total amount, and net is the amount left over after heat loss and waste has occurred. The net amount is then also the amount available to the next trophic level.

Question 7

What are the three types of ecological pyramids?

Answer 7

Pyramid of numbers, pyramid of biomass, and pyramid of energy

Question 8

What did the Linnaean system use to classify organisms?

Answer 8

Physical features

Question 9

What is a clade?

Answer 9

A group of organisms that includes an ancestor species and all of its descendants

Question 10

What are examples of decomposers?

Answer 10

Bacteria and fungi

Question 11

What are the four types of bacteria in the Nitrogen cycle?

Answer 11

decomposing, nitrifying, nitrogen-fixing, and denitrifying

Question 12

What does decomposing bacteria do with nitrogen from wastes and dead bodies?

Answer 12

Turns it into ammonium (NH4+)

Question 13

What does nitrifying bacteria do?

Answer 13

Turns ammonium into nitrates (this must happen twice in the cycle)

Question 14

What does nitrogen-fixing bacteria do?

Answer 14

Takes nitrogen from the air and turns it into ammonium

Question 15

What does denitifying bacteria do?

Answer 15

Turns nitrates into nitrogen gas

Question 16

Explain the mark recapture formula.

Answer 16

N = (M x n)/m
N = population
M = first sample all tagged
n = second full sample
m = second sample tagged

Question 17

What are some issues with mark recapture?

Answer 17

Animals can be trap happy or shy, weather can cause animals not to move, tagging can be unreliable, animals can be too rare to catch

Question 18

What is the SDI formula? Explain it.

Answer 18

SDI = 1 - Sum of n(n-1)/N(N-1)

Question 19

What is the difference between fundamental and realised niche?

Answer 19

Fundamental = where they can survive, realised = where they have to survive due to being outcompeted for resources

Question 20

What is a keystone species?

Answer 20

A species with the highest impact on the ecosystem in terms of it population

Question 21

How can you identify a keystone species?

Answer 21

By looking at who can only be eaten by one organism. The organism who is the only one able to eat that organism is the keystone species

Question 22

What is carrying capacity?

Answer 22

The maximum amount of a species that an ecosystem can sustain

Question 23

What is species richness?

Answer 23

A tally of the number of that species in a particular area

Question 24

What are the two types of factors influencing population size?

Answer 24

Density dependent and independent

Question 25

What is competitive exclusion?

Answer 25

Two species requiring the same resource cannot exist in the same niche

Question 26

What is an ecological niche?

Answer 26

A species role and position in its environment

Question 27

What are the 7 symbiosis?

Answer 27

Mutualism, cooperation, commensalism, amensalism, parasitism, competition, and predation

Question 28

What are some density dependent factors that influence population size?

Answer 28

competition, birth and death rates, predation, crowding, disease

Question 29

What are some density independent factors influencing population size?

Answer 29

weather, water availability and quality, salinity and pH, human influence

Question 30

What does SDI of 0 mean? And an SDI of 1?

Answer 30

0 = monoculture, 1 = infinite variety

Question 31

Explain SDI

Answer 31

SDI measures species richness and evenness to describe the diversity of an ecosystem

Question 32

How can organisms lose energy? (Gross - net)

Answer 32

Respiration, heat loss, waste production

Question 33

What is a limitation of SDI?

Answer 33

It is heavily weighed towards the most abundant species