ecosystems

Question 1

=name the group of organisms. that recycle biological molecules in the burned trees that died

Answer 1

saprobionts
decomposers

Question 2

niche

Answer 2

the role the species has in it community

Question 3

types of nicches

Answer 3

structural
feeding

Question 4

why two species cant occupy the same niche

Answer 4

-eg commorant vs shag birds
they both cant be successful in the same ecosystem

Question 5

abiotic

Answer 5

non living factors

Question 6

biotic

Answer 6

living fscgor

Question 7

biotic factors

Answer 7

disease and predators

Question 8

abiotic factors

Answer 8

temperature ph light inteniy

Question 9

population size

Answer 9

total number of organisms in a habitat

Question 10

carrying capacity

Answer 10

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

Question 11

what shape would a graph beb when a size of a population has just been intoduced to a new area

Answer 11

sigmaoid s shape
-species need to find mating partners and adapt to the new environment
-soon reaches maximum carrying capacity so plateus and eventually decreases as small amount of resources more competition so not enough

Question 12

competition

Answer 12

when two or more indiviudals strive to obtain the same resources where these are in short supply
the more similar the individuals the more intense the compeition

occurs when any two niche species overlap

Question 13

interspecific competition

Answer 13

-competition between organisms of the same species
-avaliability of the resources detrmine size of the population
-organisms od the same species occupy the same niche so will compete for almost everything

Question 14

competitive exclusion principle

Answer 14

where population of the two species initially occupy the same niche , one will nromally have the competitive advantage

Question 15

intraspecific competition

Answer 15

-competition between orga isms of the same species
-availabitiy of the respurces detrmine size of the population
-organisms of the same species occupy the same niche so will compete for al ost everything
-variation in the pop means that some organisms are better able to compete than others which drive evlutiond

Question 16

types of sampling

Answer 16

random sampling
systematic sampling

Question 16

what would you use for random sampling

Answer 16

quadrats

Question 17

abundance

Answer 17

the number of individuals pf a species in a given space

can be obtained by using a quadrat to measure the % cover of a plant

Question 18

three things to consdier when using a quadrat

Answer 18

-size of the quadrat used
-the number of sample quadrats to record within the study area (ensure reliable snd representative results )
-the position of each quadrat whitin the study area

Question 19

what would you use for systematic sa pling

Answer 19

transect

Question 20

motile

Answer 20

capable of moving on its own an organism can producr its own movement

Question 21

mobile

Answer 21

capable of movement

Question 22

mark ,release ,recapture

Answer 22

-capture a sample of the population to be studied
count mark them and release them
-capture a second sample
-count the total number captured and how many of them were marked

Question 23

number in the whole population

Answer 23

number first caught and marked x total in the second sample divided by number of marked indivusals in the second sample

Question 24

Classification

Answer 24

Grouping of organisms

Question 25

Taxonomy

Answer 25

The science of classification

Question 26

Phylogeny

Answer 26

The study of the evolutionary history of groups or organisms

Question 27

Two types of classification

Answer 27

Artificial
Phylogenies

Question 28

Artificial classification

Answer 28

Divides organisms may physical characteristics such as size or number of legs
Described by the sale function amd mot the same evolutionary origins

Question 29

Phylogenic classification

Answer 29

Based upon evolutionary relationships
Classifies species using shared features derived from their ancestors
Arranges the groups into a hierarchy -groups contained within larger groups with no overlap

Question 30

Why do plants need nitrogen

Answer 30

Amino acid
Chlorophyll
Dna nucleotides

Question 31

How can mineral ions be lost from soil

Answer 31

Crops take in minerals from the soil to build biological molecules there aspire removed from field at harvest
Leaching
Animal grazing
Crop intake

Question 32

Why plants struggle to get nitrogen

Answer 32

Triple bond
Very stable
Unreactive

Question 33

Atmospheric nitrogen

Answer 33

It is an inert gas the triple bind makes it very stable so not easy to break apart in chemical
Plants and animals cannot use N2
Plants must get their nitrogen in fixed form incorporated in compounds such as nitrate ions and ammonia

Question 34

Nitrogen cycle four main processes

Answer 34

1)nitrogen fixation
2)ammonification (during decomposition)
3)nitrification
4)denitrification

Question 35

Nitrogen fixation

Answer 35

1)biological fixation by microbres
2)atmospheric fixation by lightning
3)industrial fixation-Huber process to make fertiliser

Question 36

Biological nirotgen fixation

Answer 36

1)free living bacteria such as a azotobactter
2)symbiotic bacteria rhizobium in root nodules of legumes

Question 37

Ammonification

Answer 37

1)microbial saprovionts break down proteins in detritus to make ammonia
2;then remove amino acid groups from amino acids using deaminse
3)ammonia goes on to form ammonium ions in the soil when in solution

Question 38

Nitrification

Answer 38

Ammonia can be taken up directly by plants usually through their roots but most of it is converted into nitrates

This is accomplished in two steps
1) nitrosamines oxidise nh3 to nitrites
2)nitrobscter oxidse thr nitrites to nitrates

Question 39

How does a phylogenic classification system attempts to arrange organisms into a group

Answer 39

Based on homologous clharacteridfcs
Large groups with no overlaps
Based on evolutionary relation ships and origins

Question 40

Why is it often difficult to classify organisms as distinct species

Answer 40

They evolve and change
Sterile. Infertile like mule
Isolation eg. Deforestation

Question 41

Biodiversity

Answer 41

A measure of the variety of living organisms and their genetic differences

Question 42

Species diversity

Answer 42

Number of diff species and individuals of each species within any one community
Species richness

Question 43

Genetic diversity

Answer 43

Variety of genes possessed by the individuals of population that make up a population of species

Question 44

Ecosystem diversity

Answer 44

Range of different habitats

Question 45

How visible genetic diversity detected

Answer 45

Gel electrophoresis
Differences are at a molecular level

Question 46

Species richness

Answer 46

(number of different species in an area)

Question 47

Species evenness

Answer 47

(number of individuals of a species)

A highly diverse community would have a high species richness and a high species evenness.

Question 48

Index of diversity

Answer 48

Calculating biodiversity
D= N(N-1)/En(n-1)
N=total no organisms of all species
n=number of organisms in each species
E= sun off
The higher the species diversity index is the more stable the ecosystem usually is and the less it is affected by change

Question 49

Vevdv