Classification, biodiversity and conservation

Question 1

species

Answer 1

a species is a group of organisms with similar morphology and physiology, which can breed together to produce fertile offspring and are reproductively isolated from other species

Question 2

Outline what is meant by the term ecosystem?/2
(pp)

Answer 2

an ecosystem is an interaction between biotic and abiotic factors in a self contained community.
There is flow of energy within ecosystem

Question 3

habitat

Answer 3

a habitat describes the place where a species lives within an ecosystem

Question 4

niche

Answer 4

a niche is the role of an organism in an ecosystem

Question 5

Explain what is meant by the term endangered species? /2
(pp)

Answer 5

• species threatened with extinction
• population is too small so reproduction is affected

Question 6

Explain what is meant by biodiversity? /3
(pp)

Answer 6

biodiversity is:
1) variation in ecosystems
2) the number of species and their relative abundance
3) genetic variation within each species

Question 7

Explain what is meant by heterotrophic?/2
(pp_

Answer 7

• feed on other organisms
• to obtain organic compounds

Question 8

taxonomic hierarchy

Answer 8

domain → kingdom → phylum → class → order → family → genus → species

Kings Play Chess On Fancy Gold Squares

Question 9

the three domains

Answer 9

bacteria, archaea, eukarya (protists, fungi, plants, animals)

BAE

Question 10

Describe the differences between eukaryotic and prokaryotic cells with respect to their DNA?
(pp)

Answer 10

1) Eukaryotic:
-linear
- in nucleus
- associated with
proteins
- in chromosomes
2) prokaryotic:
- circular
- free in cytoplasm
- naked
- not in chromosomes

Question 11

Outline the characteristic features of organisms in the domain bacteria? /8
(pp)

Answer 11

1) unicellular prokaryotes
2) circular DNA
3) histones associated with DNA
4) smaller circular molecules of DNA called plasmids are often present
5) no membrane-bound organelles are present
6) ribosomes (70 S)
7) cell wall made up of peptidoglycans
8) cells divide by binary fission, not by mitosis
9) usually exist as single cells or small groups of cells.
10) spherical shape

Question 12

Outline the characteristic features in the domain archaea? /8
(pp)

Answer 12

1) unicellular prokaryotes
2) circular DNA
3) no histone proteins associated with DNA
4) no membrane-bound organelles
5) ribosomes (70S)
6) smaller circular molecules of DNA called plasmids are often present
7) cell wall always present, but does not contain
peptidoglycans
8) cells divide by binary fission, not by mitosis
9) usually exist as single cells or small groups of cells
10) cell membrane composition different than bacteria

Question 13

Outline the characteristic features of organisms in the domain eukarya? /8
(pp)

Answer 13

1) nucleus
2) membrane-bound organelles
3) Linear DNA
4) DNA associated with histones
5) ribosomes (80S) and mitochondria/chloroplast has 70S ribosomes
6) chloroplast and mitochondrial DNA is circular
5) a great diversity of forms: there are unicellular, colonial and multicellular organisms
6) cell division is by mitosis
7) many different ways of reproducing - asexually and sexually.

Question 14

Compare the characteristics of bacteria and Archae.

Answer 14

similarities:
1) both are prokaryotes
2) both have circular DNA
3) Both have 70S ribosomes
4) both reproduce by binary fission

differences:
1) bacteria cell wall is
made up of
peptidoglycan
whereas archaea cell
wall does not have
peptidoglycan
2) they have different
ribosomal RNA
3) Bacteria do not have
DNA associated with
histones whereas
Archaea do not have
DNA associated with
histones
4) bacteria form spores
whereas archaea do
not form spores

Question 15

Outline the characteristic features of the organisms of kingdom Fungi

Answer 15

1) heterotrophic
2) none contain chlorophyll so does not photosynthesise
3) reproduce by spores
4) cells have cell walls made of chitin
5) never have cilia or flagella
6) mostly multicellular, some unicellular

Question 16

Describe the main features of an organism belonging to the kingdom Plantae? /8
(pp)

Answer 16

1) multicellular eukaryotes 2) cells that are differentiated to form tissues and organs
2) few types of specialised cells
3) some cells have chloroplasts and photosynthesise
4) cells have large permanent vacuoles
5) autotrophic nutrition
6) cell walls are made of cellulose
7) cells may occasionally have flagella - e.g. male gametes in ferns
8) complex body forms with branching systems above and below the ground
9) most have vascular bundle

Question 17

Outline the characteristic features of the kingdom Animalia? /8
(pp)

Answer 17

1) multicellular eukaryotes 2) many different types of specialised cells
3) cells that are differentiated to form tissues and organs
3) motile
4) cell vacuoles are small and temporary
5) heterotrophic nutrition
6) cells do not have cell walls
7) communication is by the nervous system
8) cells sometimes have cilia or flagella

Question 18

outline the characteristic features of the kingdom Protoctista?

Answer 18

1) unicellular, some colonial
2) some are heterotrophic and some are autotrophic
3) cellulose cell wall in some
4) Vacuole present
5) some have flagella

Question 19

Discuss the ways in which members of the kingdom protoctista are similar to each other and ways in which they are different.
(pp)

Answer 19

similarities:
- eukaryotic cells
- eukaryotic cells so they
have linear DNA and
80S ribosomes
differences:
- can be single celled or
multicellular
- autotrophic or
heterotrophic
- cell wall or no cell walls
- vacuole or no vacuole
- motile or not able to
move
- different life cycles

Question 20

Name two kingdoms that are exclusively heterotrophic

Answer 20

animalia and fungi

Question 21

explain why viruses are not included in the three domain classification

Answer 21

viruses have none of the features that are traditionally used for classification

Question 22

Describe the features of viruses? /8
(pp)

Answer 22

1) not cellular
2) contain nucleic acid (RNA/DNA) core
3) DNA may be single stranded or double stranded
4) core surrounded by protein coat
5) may have external membrane
6) replicated in host cells
7) viruses are pathogenic
8) no metabolism
9) immobile
10) have enzymes to cause replication
11) specific to host cells
12) not living

Question 23

four groups of viruses

Answer 23

1) DNA single-stranded viruses
2) DNA double-stranded viruses
3) RNA single-stranded viruses
4) RNA double-stranded viruses

Question 24

the two types of sampling

Answer 24

random sampling and systematic sampling

Question 25

when should random sampling be used?

Answer 25

1) when an area looks reasonably uniform
2) no clear pattern to the way the species are distributed
*samples must be taken randomly to avoid bias

Question 26

Random sampling using frame quadrats method

Answer 26

1) mark out the area to be sampled using string and marker pole
2) use random number generator to obtain coordinates
3) Place quadrat on ground at random coordinates
4) Identify species within quadrat using nature guide
5) estimate species abundance using
1) species density=
Total No. of
individuals
Calculated/ total
area of all quadrats
2) estimating
percentage cover
3) Braun- Blanquet
cover abundance
scale/ ACFOR scale
6) repeat many times

Question 27

when should systematic sampling be used?

Answer 27

useful for non uniform distribution

Question 28

Types of systematic sampling

Answer 28

line transect and belt transect

Question 29

Difference between line transect and belt transect

Answer 29

1) line transect- all organisms touching the line and recorded
2) belt transect- only organisms in the frame quadrat at each interval are recorded

Question 30

method of systematic sampling

Answer 30

1) lay out a line/tape running across a certain area
2) line transect or belt transect
3) use nature guide to identify different species
4) estimate species abundance :
1) species density=
Total No. of
individuals
Calculated/ total
area of all quadrats
2) estimating
percentage cover
3) Braun- Blanquet
cover abundance
scale/ ACFOR scale 5) repeat sampling

Question 31

What method is to investigate population of motile organisms?

Answer 31

mark-release-recapture method

Question 32

What are the assumptions for mark release recapture method? /3
(pp)

Answer 32

1) marking animals in a way that it does not harm animals
2) constant population size
3) no births or deaths or any migration
4) sufficient time for individuals to mix with rest of population

Question 33

Method of mark release recapture method?/5
(pp)

Answer 33

1) as many individuals as possible are caught and counted using traps

2) each individual is marked, in a way that will not affect its future chance of survival

3) marked individuals are returned to their habitats to mix randomly with their population

4) after enough time has elapsed, a large sample is recaptured

5) number of marked and unmarked individuals are counted

6) population size estimate using Lincoln’s index: (number in 1st sample x number in second sample)/ number in second sample that are marked

Question 34

Spearman’s rank correlation

Answer 34

• Spearman’s rank correlation determines whether there is correlation between variables that don’t show a normal distribution

Question 35

when to use Spearman’s rank correlation?

Answer 35

use when data:
1) data points are independent of each other
2) data is correlated, but not linear (draw scatter diagram first)

Question 36

method of spearmen’s rank correlation

Answer 36

1) make a null hypothesis that there is no correlation between the percentage cover of the two species
2) draw a scatter graph to see if it looks as if there is a correlation between the abundance of the two species
3) if the value calculated for Spearman’s rank is greater than the critical value at p=0.05, then the null hypothesis can be rejected, meaning there is a correlation between two variables

Question 37

Pearson’s linear correlation

Answer 37

• Pearson’s linear correlation is a statistical test that determines whether there is linear correlation between two variables
• data must be quantitative and show normal distribution

Question 38

method of Pearson’s linear correlation

Answer 38

1) create a scatter graph of data gathered and identify if a linear correlation exists
2) state a null hypothesis
3) if the correlation coefficient r is close to 1 or -1 then it can be stated that there is a strong linear correlation between the two variables and the null hypothesis can be rejected

Question 39

Outline the difference between Pearson’s and Spearman’s correlation coefficients

Answer 39

Pearson’s correlation coefficient is used for linear correlations between two data sets

Spearman’s correlation coefficients works for linear correlations and monotonic relationships (does not increase/decrease by the same amount each time)

Question 40

Simpson’s Index of Diversity

Answer 40

a measure of biodiversity between 0 and 1 that takes into account both species richness and species evenness

• values near 1 indicate high levels of biodiversity
• values near 0 indicate low levels of biodiversity
• used to quantify the biodiversity of an area

*n: total number of organisms in one species

*N: total number of organisms of all species

Question 41

How an ecological survey can measure the biodiversity of the terrestrial habitat? /4
(pp)

Answer 41

1) use random sampling
2) repeat and find mean for whole area
3) use frame quadrats for plants
4) use quadrats of same size and place at random coordinates
5) use mark-release-recapture method for animals
6) mark animals in a way that it has no adverse effect on the animals
7) use simpson’s index of biodiversity to measure biodiversity of both species richness and species evenness

Question 42

five major threats to biodiversity

Answer 42

1) habitat loss and the degradation of the environment

2) climate change

3) excessive use of fertilisers and industrial and domestic forms of pollution

4) the overexploitation and unsustainable use of resources

5) the effects of invasive alien species on native species, especially endemics

Question 43

threats to the biodiversity of aquatic ecosystems

Answer 43

1) overfishing (very difficult to know whether fish stocks are sustainable), example of overexploitation of resources
2) fishing further down the food chain taking smaller fish that other animals depend on influences their populations too
3) non-biodegradable plastic is a major marine pollutant
4) fertilisers that have not been absorbed by crop plants drain into aquatic ecosystems causing the overgrowth of producers such as algae faster than herbivores can feed on them
5) algae producing toxic substances and affecting coral reefs
6) acidification of marine ecosystems due to acid rain reducing the biodiversity as few animals are able to survive/breed in waters of low pH
7) coral bleaching due to increase in water temperature due to increase in greenhouse gases

Question 44

threats to the biodiversity of terrestrial ecosystems

Answer 44

1) global warming (cattle and rice farming, breakdown of organic waste in landfills under anaerobic conditions increasing methane emissions) is likely to produce changes in the distribution of terrestrial ecosystems
2) when organisms migrate to cooler areas, competition would occur between migrating organisms and species in existing communities
3) some ecosystems will become even more restricted in their range due to global warming causing problems for coastal ecosystems

Question 45

Suggest why a smaller area of marine habitats has been protected than of terrestrial habitats?
(pp)

Answer 45

• marine environment is difficult to monitor
• lack of public awareness
• difficult to set boundaries

Question 46

Suggest why tropical rainforests have a high biodiversity of animal species?
(pp)

Answer 46

1) rapid growth of plants
2) large number of plant species
3) leaves for animals throughout the year for animals
4) provides habitat

Question 47

Explain why tropical rainforest is considered to have a very high ecological importance?
(pp)

Answer 47

1) has very high species diversity
2) is being lost rapidly
3) loss may lead to global warming
4) loss may affect rainfall patterns
5) loss may affect soil erosion

Question 48

Suggest why the separation of habitat into small fragments, rather than a large single area, poses a threat to the long term survival of this species?
(pp)

Answer 48

• less choice of mates
• could lead to inbreeding
• decrease in hybrid vigor
• decrease in genetic variation
• more areas are more vulnerable to damage than large ones
• more easily exposed to danger outside area

Question 49

discuss the reasons for the need to maintain biodiversity. /7
(pp)

Answer 49

• economic reasons:
  - resource material such
  as wood for building,
  fibres for clothes, food
  for humans
  
  • species may be used in
    future for medical
    research
• for ecotourism
• ecological reasons:
  - maintaining genetic
  diversity
  - maintaining food webs
  - nutrient cycling
  - climate stability
  - protection against soil
  erosion
• ethical reasons:
  - prevent extinction
  
  • allows indegenous
    people to conserve its
    own culture

Question 50

endangered species

Answer 50

an endangered species is one that is threatened with extinction

Question 51

List of methods of protecting endangered species

Answer 51

1) zoos
2) botanic gardens
3) conserved areas (national parks and marine parks)
4) ‘frozen zoos’
5) seed banks

Question 52

Outline the role of zoos in the conservation of endangered species? /4
(pp)

Answer 52

1) zoos have captive breeding programmes
2) the goal of captive breeding programme is to increase number of endangered species and release to wild
3) assisted reproduction by AI or IVF to increase number
4) medical care
5) public awareness
6) projects in the field
7) maintaining genetic databases to avoid interbreeding

Question 53

Discuss the role of botanic gardens in the protection of endangered species? /7
(pp)

Answer 53

1) collect plants from the wild
2) from many countries
3) especially from areas at risk from climate change
4) grow seeds in botanic gardens
5) Increased seed number
6) tissue culture
7) store in seed bank
8) maintain genetic diversity
9) cooperate with governments for research
10) to conserve habitats
11) to restore habitats
12) to reintroduce species into wild
13) raise awareness
14) raise funds

Question 54

Describe the role of seed banks in the protection of endangered species?/7
(pp)

Answer 54

1) collection of seeds
2) long term storage
3) storage to prevent germination
4) stored at frozen conditions
5) seeds regularly tested for viability
6) seeds re-stocked regularly
7) maintain genetic diversity
8) can be used in future to increase number
9) maintains biodiversity
10) education
11) takes up less space than growing plants

Question 55

methods of assisted reproduction

Answer 55

1) in vitro fertilisation (IVF)
2) artificial insemination (AI)
2) embryo transfer
3) surrogacy

Question 56

why assisted reproduction is useful

Answer 56

1) it’s a solution to the problem of inbreeding
2) solve the problem of males and females who do not show any courtship behaviour and will not mate
3) movement of large mammals is difficult, expensive and breeding does not always happen so sperm is collected which can then be used in assisted reproduction

Question 57

Describe how IVF can be used with endangered species?
(pp)

Answer 57

1) females are given hormones for superovulation
2) oocytes are harvested from females using fine needle
3) sperms obtained and is mixed with oocytes
4) cultured for several days until embryo survives
5) Transfer embryo into uterus

Question 58

Discuss the ethical implications of IVF? /7
(pp)

Answer 58

1) not natural
2) possible birth defects
3) only wealthy can access IVF
4) some embryo’s discarded
5) unknown effects of freezing embryos for storage
6) issues regarding selection of gender
7) issues regarding surrogate mothers
8) extending age of conception of women past menopause

Question 59

Describe the procedure of embryo transfer in a mammal?
(pp)

Answer 59

1) embryo is formed during mating or IVF
2) so embryo is removed from female uterus which mated
3) select healthy embryos
4) may freeze embryo for later use
5) implant embryo in uterus of surrogate mother

Question 60

Suggest how the seeds should be stored in the seed banks to keep them viable for future?
(pp)

Answer 60

kept cool/dried

Question 61

Discuss the advantages and disadvantages of captive breeding programmes for mammals? /8
(pp)

Answer 61

Advantages:
1) can monitor health of
mother
2) can monitor health of
fetus
3) storage of sperms and
eggs
4) assist reproduction by
IVF or AI
5) international
cooperation
6) genetic records kept
7) can prevent extinction

Disadvatages:
1) unnatural
environment
2) stress in captivity
3) behaivioral changes
4) may reject mates
5) reproductive cycles
disrupted
6) more susceptible to
diseases

Question 62

Suggest why species can become extinct?
(pp)

Answer 62

1) Climate change
2) habitat loss
3) hunting by humans
4) competition for food and resources
5) new diseases
6) species cannot adapt fast enough
7) numbers get so low that population cannot recover

Question 63

alien species

Answer 63

alien or invasive species are those that have moved from one ecosystem to another where they were previously unknown

Question 64

causes of alien species

Answer 64

1) humans trading animals and plants or unwittingly carrying them on ships
2) introduced as biological control agents to control pests
3) escapees
4) animals introduced for sport

Question 65

effects of alien species

Answer 65

1) successful predators with few controls (no natural predators of it in new environments)
2) may compete effectively with native organisms that occupy the same niche, pushing them to extinction
3) may also introduce diseases that spread to similar organisms that have never been exposed to the pathogens
4) outcompete native species simply by reducing the space where they can grow

Question 66

Explain why the introduction of alien species should be avoided?
(pp)

Answer 66

1) invasive species reduce other organisms abundance
2) they alter food webs
3) they lack predators
4) may prey on native organisms
5) may compete with local organisms
6) may introduce diseases
7) may change habitat for example they may change pH of soil
8) may threaten human health so can have effects on food chain
9) may decrease biodiversity

Question 67

non-governmental organisations involved in local and global conservation

Answer 67

1) IUCN

2) the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES)

Question 68

Outline the role of IUCN
(pp)

Answer 68

1)IUCN is a global authority
2) to conserve biodiversity
3) IUCN red lists threatened and endangered species
4) it categorises species conservation status
5) spreads awareness
3) provides advice about conservation issues
5) influence governments

Question 69

Suggest ways by which CITES attempts to regulate the trade in wild fauna and flora?
(pp)

Answer 69

1) CITES is trade agreement between governments
2) trade ban of species is in danger of extinction
3) if species is not at risk of extinction then trade permit is required
4) border checks to ensure no illegal activity is occuring
5) each country is provided with list of endangered species
6) encourages countries to join CITES

Question 70

Explain how the classification of species into taxonomic hierarchy assists the work of conservation bodies such as the IUCN?
(pp)

Answer 70

1) records biodiversity
2) so conservation decisions can be made
3) such as the IUCN which red lists threatened and endangered species
4) CITES is the regulation of trade
5) taxonomic hierarchy is internationally recognised

Question 71

How non governmental organisations contribute to conservation?
(pp)

Answer 71

1) IUCN red lists threatened and endangered species
2) raise funds
3) bans hunting and deforestation
4) research
5) conserves biodiversity
6) raise awareness
7) holds protests
8) promote coexistence of wildlife and people
9) CITES regulate wildlife trade
10) bans trade if species are extinct

Question 72

Suggest reason why the red list has many more vertebrates than invertebrates?
(pp)

Answer 72

• vertebrates are more visible as they are larger
• people are more interested in vertebrates

Question 73

outline how degraded habitats may be restored, with reference to named examples? /7
(pp)

Answer 73

1) replanting
2) re introduction of native animal species
3) bioremediation
4) Bubbling oxygen through water
5) normalising pH of water bodies
6) purifying water bodies
7) waste removal
8) removal of toxic layer of soil
9) improving soil fertility
10) removal of alien species
11) protection against grazing

Question 74

Explain the consequences on genetic diversity of having a wild population of just 6 birds
(pp)

Answer 74

1) decreased genetic diversity
2) decreased heterozygosity
3) harmful recessive alleles may come together
4) inbreeding depression
5) decreased hybrid vigour
6) less able to adapt to changed environment