Population

Question 1

Teen population

Answer 1

A group of organisms of the same species

Question 2

Population numbers increase because of

Answer 2

Birth and immigration

Question 3

Population numbers decrease because of

Answer 3

Death and emigration

Question 4

In stable population

Answer 4

Birth + immigration = deaths + emigration

Question 5

Density dependent

Answer 5

Abiotic - living
Affect greater proportion of population

Question 6

Density independent

Answer 6

Biotic - non living

Question 7

Term carrying capacity

Answer 7

Maximum number of individuals of species that the environment can support indefinitely

Question 8

Phases of population growth

Answer 8

LAG
LOG
STATIONARY
DEATH

Question 9

Lag (yeast)

Answer 9

Enzymes are synthesised
Dna is replicated

Question 10

Log ( yeast)

Answer 10

Population doubles every unit of time
Nutrients abundant

Question 11

Stationary ( yeast)

Answer 11

Competition of nutrients means death and cell reproduction happen at the same time

Question 12

Death ( yeast)

Answer 12

Nutrient depletion and toxin accumulation mean death rate is higher than cell reproduction

Question 13

Ecosystem

Answer 13

An area that has a particular community of plants and animals interacting with their environment

Question 14

Term community

Answer 14

All of the organisms of all species in an ecosystem

Question 15

Term habitat

Answer 15

Place in the ecosystem where organisms live

Question 16

Term niche

Answer 16

An organisms role in ecosystem
Applies particularly to their feeding role

Question 17

Photoautrophs

Answer 17

Mainly green plants
Use light energy from the sun to fix carbon dioxide into organic molecules by photosynthesis

Question 18

GPP - R= NPP

Answer 18

Gross and net primary productivity

Question 19

Why is some energy never taken in at each trophic level

Answer 19

Some parts of food aren’t consumed
Some parts of food indigestible
Plants can’t use all light energy as some is the wrong wavelength

Question 20

Why is some energy lost at each trophic level

Answer 20

Respiration
Lost as heat

Question 21

Pyramid of biomass

Answer 21

A table of dry mass of living material at each trophic level of a food chain

Question 22

Gross primary productivity

Answer 22

The rate of chemical energy fixture during photosynthesis by all producers in an ecosystem

Question 23

Net primary productivity

Answer 23

The amount of chemical energy that is available to the heterotrophs in an ecosystem

Question 24

How to calculate net primary productivity

Answer 24

Gross primary - respiratory losses

Question 25

Term succession

Answer 25

Is the change in structure and species of a community overtime

Question 26

Term secondary succession

Answer 26

Starts from cleared land where communities have lived before It is faster as there are seed roots and soil to support the plants Happens after forest fires or tree felling

Question 27

Term Sere

Answer 27

Each stage of succession

Question 28

How is succession depleted

Answer 28

1. Mowing 2. Burning 3. Grazing

Question 29

Term primary succession

Answer 29

Starts from bare rock where no organisms lives

Question 30

What are pioneer species

Answer 30

Species that can survive in hostile environments and colonise bare rock Eg Lichens

Question 31

Process of primary succession

Answer 31

1. Pioneer species colonise the area 2. They die decompose and add nutrients to the ground 3. Over time this allows more complex organisms to survive

Question 32

Climax community

Answer 32

Final stage of succession where ecosystem is balanced and stable

Question 33

What does succession increase

Answer 33

2. Species diversity 1. Stability of community

Question 34

Risk assessment of investigation

Answer 34

1. Biting insects 2. Stinging plants 3. Cover skin 4. Use insect repellent Weather conditions - 1. Sunburn 2. Hypothermia

Question 35

Representative sampling

Answer 35

Use the correct size grid/quadrant for area Carry out enough repeats

Question 36

Carbon cycle

Answer 36

1. Plants take in CO2 and use it in photosynthesis to make organic molecules passed through food chains 2. Plants and animals respite and excrete CO2 3. Combustion releases CO2 4. Decomposes respire excreting CO2 5. Formation of fossil fuels

Question 37

Autotrophs

Answer 37

Use energy from sunlight or chemicals to convert inorganic compounds into organic ones Organic compounds are passed along food chains

Question 38

Decomposers

Answer 38

Use organic molecules and convert them to inorganic compounds

Question 39

Human impact on carbon cycle

Answer 39

1. Deforestation 2. Combustion 3. CO2 greenhouse gas 4. Global warming 5. Agricultural practises

Question 40

What does deforestation do

Answer 40

It removed trees so less photosynthesis takes place so less CO2 is absorbed from the atmosphere

Question 41

What does combustion do

Answer 41

Combustion of fossil fuels and wood releases locked in CO2 to the atmosphere

Question 42

Greenhouse gas on carbon cycle

Answer 42

Traps heat and raises global temperatures therefore causing global warming

Question 43

Global warming on carbon cycle

Answer 43

Affects species distribution as regions further up north and south of the equator are warmer

Question 44

Decomposition rate is affected by

Answer 44

Temperature - slower when cold pH - slower when acidic O2 availability - slower when less oxygen available

Question 45

Carbon footprint

Answer 45

Is the total amount of CO2 released attributable to an individual, product or service over the course of a year

Question 46

Water logged soils

Answer 46

Lack o2 this favours denitrification and slows nitrification This leads to nitrate poor soil - ploughing introduces air into soil - drainage ditches reduce water logging and denitrification

Question 47

Nitrifying bacteria

Answer 47

Nitrosomonas Nitrobacter

Question 48

Nitrosomonas

Answer 48

Convert ammonium to nitrite

Question 49

Nitrobacter

Answer 49

Convert nitrite to nitrate

Question 50

Nitrogen fixing bacteria

Answer 50

Convert nitrogen gas to ammonium Azotobacter Rhizobium

Question 51

Azotobacter

Answer 51

Free living in soil

Question 52

Rhizobium

Answer 52

In root nodules of legumes symbiotic

Question 53

Denitrifying bacteria Convert nitrate to nitrogen gas

Answer 53

Pseudomonas - thrive in water logged soils