B6.1

Question 1

define a sample

Answer 1

observations or measurements from a small area which can be sized up represent a larger area

Question 2

why is a sample so useful?

Answer 2

as it would be almost impossible to count all organisms or plants individually across a whole area

Question 3

describe 5 ways to capture insects, and why we need to use this specific kind of technique (special word)

Answer 3

• pooters
• sweep net
• kick sampling
• tree beating
• pit fall traps
• we have to use capture recapture techniques as they move around so we cant easily count them

Question 4

what is the use of a scaling-up method?

and why would you do so

Answer 4

you can make an estimate of a larger area by looking at a smaller sample and its distribution

• it would take too long to count all organisms/plants individually

Question 5

use of random sampling?

Answer 5

to ensure no bias is present in the results

Question 6

what is a quadrat?

Answer 6

a square divided into grids where the organisms are then counted

Question 7

what would you use to measure biodiversity over an area?

- and how would you carry it out

Answer 7

a transect

- place a piece of tape down, and have quadrats at equal intervals across the area

Question 8

what kind of organisms are the following sample techniques used to trap?
(and brief description how)

a) pooters
b) sweep nets
c) kick sampling
d) tree beating
e) pit fall traps

Answer 8

a) small insects
- suck on a mouthpiece, the insect drops into the test tube

b) larger insects (some can fly)
- large net catches insects

c) insects/small vertebrae in water
- disturbs vegetation in sea bed + collects it with a net/mesh bag

d) inverebraes that live in trees
- hit/shake branches of tree and see what insects fall off the tree + onto white sheet

e) crawling invertebraes: beetles, spiders, slugs
- they drop into hole + cannot run away
- cover hole with roof so trap does not fill with rainwater

Question 9

what is an invertebrae?

and give an example

Answer 9

any organism that has no back bone (ie. insects)

Question 10

what is an identification key used for? (and a brief explanation of how it works)

Answer 10

to identify living organisms

- by asking a series of questions about an organism’s characteristics

Question 11

two types of idenitification keys

Answer 11

• branched key /spider key (like a huffman diagram i guess)

- numbered key / dichotomous key (like a grid thing) - check notes

Question 12

how do you estimate the total population of an area (using a quadrat)?

Answer 12

mean population (per meters squared) x total area

Question 13

how do you estimate the population size using a capture-recapture technique?

Answer 13

first sample size x second sample size / number of recaptured marked individuals

Question 14

when would non-random sampling be used?

Answer 14

when working out how organism distribution varies over distance

Question 15

describe 4 positive human interactions within an ecosystem

Answer 15

• conservation
• captive breeding
• seed banks
• reducing rate of deforestation

Question 16

how does conservation imapct biodiversity?

Answer 16

• protects a natural environment to ensure habitats/animals are not lost
• increases their chance of survival

Question 17

give 4 factor of an area where conservation occurs (and give an example of where)

Answer 17

• nature reserve
  eg.
• controlled grazing
  —> only allowing animals to graze land for a certain period of time, giving plant species time to recover

restricting human access
—> for example by providing paths to prevent plants being trampled

• feeding animals
  —> to ensure more organisms survive to reproductive age
• reintroduction of species
  —> adding new individuals of a species into an area where numbers have decreased significantly, or where species has not survived

Question 18

what is captive breeding? (give an example)

Answer 18

breeding animals in human-controlled environments (ie. zoo/ aquarium)

Question 19

what do scientists use captive breeding for?

Answer 19

• create a stable + healthy population of a species

- reintroduce species to natural habitat

Question 20

positives and negatives of captive breeding?

Answer 20

pos - no predators, veterinary care given, food given = species has a greater chance of survival

neg - difficult to maintain genetic biodiversity (as few breeding partners are available)
- organisms born in captivity may not survive in the wild (e.g. predators may not know how to hunt for food)

Question 21

seed banks

• what are they an example of
• what is the purpose?
• how are they stored?

Answer 21

• example of a gene bank
• purpose is to backup against the extinction of plant species
• seeds are cleaned, dried, stored in airtight jars

Question 22

what are the threats of deforestation use on biodiversity within an ecosystem?

Answer 22

• deforestation (wood for building, space) - biodiversity decreases (loss of food source/ home)

Question 23

how does agriculture affect the ecosystem and biodiversity? 3

Answer 23

• remove hedgerows for more space (loss of habitat for those animals, and reduction in number of plant species)
• pesticides (remove food source for other organisms)
• pesticides accumulate in food chain, killing animals that were not targeted
• herbicides used to kill plants growing where not wanted (reduces num. plant species present, but also removes a source of food/shelter for animals)

Question 24

why is biodiversity important?

Answer 24

since species are interdependant within an ecosystem, and so removal of one could affect many different species

Question 25

benefits of maintaining local and global biodiversity?

Answer 25

• more species survive (allows ecosystems to thrive + not die)
• some animals may migrate (so all countries must have agreements)
• ecotourism (bring money to support conservation + educates people)
• medicines uncovered (to treat diseases)
  ___
• raw materials for humans: food, wood, oxygen

Question 26

challenges of maintaining local and global biodiversity?

Answer 26

• difficulty in gaining agreements
• conservation costs money
• hard to change laws/legislations

Question 27

negatives of ecotourism?

Answer 27

tourist movement may cause erosion to the floor or habitat changes

Question 28

difference between ecotourism and normal tourism?

Answer 28

ecotourism aims to ensure tourism does not have a negative effect on the environment

SUPPORTS CONSERVATION

Question 29

define an indicator species

Answer 29

organisms that can be used to measure environmental quality either through their presence or absence

Question 30

how are lichen used to monitor air pollution?

Answer 30

lack of lichens is a sign of air pollution

- or the type of lichens found in a specific area

Question 31

why are lichens used as an indicator species?

Answer 31

as they have no root system, and get all nutrients from the air

Question 32

what are the 4 indicator species to monitor Water pollution? (and what does the presence/ lack of presence for each one mean)

Answer 32

mayfly larva (nymphs) - unpolluted water

freshwater shrimp - low pollution

waterlouse - high pollution

sludgeworm - very high pollution

Question 33

what do the organisms found in polluted water differ of?

Answer 33

differ by the oxygen content within the water (and how much oxygen they need to survive)

Question 34

how does oxygen generally differ in terms of pollution?

Answer 34

higher pollution levels mean lower oxygen content

Question 35

what are quadrants used to measure?

Answer 35

only sedentary organisms - ie. plants

as animals move

Question 36

why are capture-recapture methods used for animals\/

Answer 36

as they continually move

Question 37

Problem w/ fishing

Answer 37

• overfishing has led to some fish populations decrasing significantly, or even being lost from somewhere areas
• other marine speices may also be caught and killed

Question 38

Problem w/ hunting.

Answer 38

• hunting decreases the target species’ population, which removes food for other species
• this may allow the unchecked growth of some plant species, which then outcompete other planets —> further reduces biodiversity