4A Biodiversity and 5B Climate Change Flashcards
(85 cards)
1
Q
why is little genetic diversity bad?
A
increases risk of extinction of population through inbreeding depression
- no selective adv. when env. changes
2
Q
why does biodiversity need to be maintained?
A
loss of biodiversity = fewer species = loss of endemic species leads to extinction
3
Q
how is species richness counted?
A
counting number of species in a known area using quadrat
4
Q
what needs to be measured in order to compare biodiversity of two diff habitats?
A
-
species richness
-> for measuring biodiversity WITHIN habitat
-> count no. of different species and no. individuals in each species
-> use index of diversity
5
Q
how is genetic diversity of a species measured?
A
- phenotype -> noting observable characteristics you can get an idea of diversity of alleles
- genotype -> samples of organism’s DNA taken and base pairs analysed
->diff order of bases in diff alleles
6
Q
niche
A
- role of species within habitat
- interactions with biotic and abiotic factors
7
Q
how are animals adapted to their niche for a higher chance of survival?
A
- BEHAVIOURAL -> how it acts eg. plays dead
- PHYSIOLOGICAL -> processes inside body eg. hibernation
- ANATOMICAL -> structural features eg. streamlined body = faster = more prey caught
8
Q
biodiversity
A
variety of living organisms in area
9
Q
how does human activity affect biodiversity?
A
eg. farming and deforestation
decreases species diversity = decreases biodiversity
10
Q
climax community
A
biggest and most complex community at a stable/steady state
11
Q
ecosystem
A
all biotic and abiotic factors in area
12
Q
community
A
all organisms of DIFFERENT species that live in same habitat and interact with each other
13
Q
population
A
all organisms of ONE species in habitat
14
Q
describe INTERspecific competition
A
between different species
- competing for same food/habitat
- leads to less resources available for both species
- eg. same food source -> populations limited by this -> less energy for growth and reproduction -> smaller pop.
15
Q
describe INTRAspecific
A
within species
- lots of resources = bigger pop. BUT more organisms competing for same amount of food
- limited resources = smaller pop.
- small pop. = less competition -> better for growth and reproduction = bigger pop.
MAX STABLE POP SIZE that ecosystem can support = CARRYING CAPACITY
RA TA TA TAAH in the ghetto the homies stick together
16
Q
how are prey and predator populations linked?
A
- more prey = more food for predators = more predators
- more predators = more prey eaten = less prey
- less prey = less food for predators = less predators
17
Q
distribution
A
WHERE species is within area
varies due to ABIOTIC factors:
- plants growing on south facing slopes -> where highest light intensity is
- no shoreline plants -> soil too salty
- no large trees in polar regions -> too cold
18
Q
what is the Net Primary Productivity
A
rate at which energy is stored in plant biomass
NPP = GPP - R
19
Q
how do scientists share their data with the scientific community?
A
- data peer-reviewed by other scientists
- data published in scientific journals
- repeats / checking of evidence to ensure validity -> try to replicate results
20
Q
how does natural selection lead to adaption and evolution?
A
M ust
S ell
A ll
C ars
- MUTATIONS -> introduce new alleles = higher genetic variation = variation of characteristics
- SELECTIVE PRESSURES -> eg. predation, disease, competition = struggle for survival
- ADV. CHARACTERISTICS -> increases survival chance -> pass adv. alleles onto offspring
leads to CHANGE IN ALLELE FREQ. (over time) -> adv. characteristics become more common over time
leading to evolution
21
Q
what conditions are needed for Hardy-Weinberg equation to work?
A
- no mutations
- random mating
- big population
22
Q
what is the Hardy-Weinberg equation used for?
A
to predict
- change in allele freq. in pop over time
- geno/phenotype freq.
p2 + 2pq + q2 = 1
p + q = 1
23
Q
species richness
A
no. of DIFFERENT species in one area
24
Q
explain how breeding programmes in zoos maintain the GENETIC DIVERSITY of captive populations
A
- animals selected to prevent inbreeding depression
- STUDBOOK used to select individuals for mating
- exchange of animals BETWEEN zoos
25
what are the **problems** of captive breeding programmes?
- can have problems breeding **outside env**. -> **hard to recreate**
- **cruel**? to keep in captivity
26
succession
**series of changes** of organisms present in area **OVER PERIOD OF TIME**
27
climate change
when **weather conditions** in region **change significantly** over a **long period of time**
28
what is global warming?
**increase** in **global temps** due to an **increase in GHGs**
- GHGs build up in atm -> prevents more long wave / infrared heat radiation from escaping
29
what are the major **problems** of global warming?
- **enzymes denature** at high temp -> affects resp, p/s and other metabolic processes
- bird migration
- feeding / breeding patterns disrupted
- **glacier melt** / **sea level rising** -> loss of habitats, niches, food sources
- ocean **acidification** -> **pH decreases**, coral bleaching
- increase in **extreme weather** events -> flooding, forest fires
30
dendrochronology
using growth rings on trees as historical data for global warming
- trees increase in width as they get older
- **better climate conditions** in early summer
= better **growth rate** (faster cell ÷ and larger cells)
= **growth in cambium** (meristematic ring of tissue between xylem and phloem)
= **thicker rings**
pattern of rings tell us how **local climate** has varied year by year
- as **conditions** get more **difficult** = **smaller** new cells
- eventually **growth stops** for the year until next spring
-> gives appearance of rings
31
main GHGs
- CO₂
- methane
- water vapour
32
role of GHGs
reduce infrared heat loss from surface of earth
33
main **effects** of global warming?
| effects = not all bad, some good!!
- rising temp
- rising **sea level**
- changing **rainfall** patterns
- changing seasonal cycles
- change in distribution of species
- change in development / lifecycles of organisms
- **human** society -> **competition** for land, food, fresh water
34
what is **peat**
- under **waterlogged** and **acidic conditions**
- **partly decomposed** dead plant matter so packed with **organic material**
- accumulates and becomes **compacted** under own weight over time
**preserves pollen grains** -> can be analysed and used as source of evidence for climate change
35
what are 4 pieces of evidence for climate change?
- dendronology
- temp records
- pollen in peat bogs
- records of CO₂ levels
36
how can ice cores be used to measure climate change?
- water **freezes** and **air bubbles** become **trapped**
- CO₂ conc measured
- ratio of **diff O₂ isotopes** measured -> gives estimate of average **air temp** when ice formed
37
what are the **causes** of anthropogenic climate change? refer to the role of GHGs in the greenhouse effect
- burning fossil fuels
- farming
- deforestation
-> all release **CO₂** and **methane** / **increase atm conc of these GHGs**
-> which **enhances greenhouse effect**
-> and causes rise in average global temp a.k.a global warming
38
how is **methane** produced? where does it come from?
- **anaerobic decay** of organic matter in **waterlogged conditions**
- decay of domestic waste in landfill
- decomposition of animal waste
- produced in **dig systems of cattle** when they fart / burp
- **incomplete combustion of fossil fuels**
39
suggest why climate models aren't perfect
/ state the **limitations** of climate models
- limited and **extrapolated data**
-> IPCC produced models based on several emissions scenarios
-> do not know **which** of these scenarios is **most likely**
- **limited knowledge of climate system**
- limitations of **tech** -> do not know whether future tech will be successful at removing GHGs from atm
## Footnote
check if accurate enough
40
state 3 **human activities** that increase atmospheric methane / CO₂ conc
- burning fossil fuels (for industry and cars)
- farming
- deforestation
41
what is the greenhouse effect?
the increase of global temps caused by the **trapping of solar heat** by gases in the atm
## Footnote
is this the perfect def??
42
data extrapolation
- process of **predicting unknown data** using **trends** in known datasets ...
- ... which has many applications eg. **predicting changes** in **climate** for future
43
anthropogenic climate change
changes in climate caused by **human activity**
44
kingdom Protoctista
eg. algae
- **eukaryotic** cells
- usually live in water
- **single celled** or **simple multicellular organisms**
45
what is the species concept?
species in **same genus** can be v similar
BUT **separate species** as **cannot breed together** to produce **fertile offspring**
46
what are the 3 domains of life based on molecular phylogeny?
- Bacteria (prokary)
- Archaea (prokary)
- Eukaryota
47
how is peat used as a source of climate change?
- pollen grains in peat -> can determine what **plant pollen came from** then what **climate** can plant **survive** in?
- **deeper** the pollen is found = **longer ago** (in geological time) plants were present
48
what are the **specific climate conditions** needed for lots of growth in trees?
| to do with denrochronology
- higher temp -> affects enzyme activity
- more water -> turgidity, p/s
- mineral ions
- higher CO₂ conc -> p/s
- higher light intensity -> p/s
49
suggest ways of **reducing carbon emissions** that lead to climate change
to reduce Carbon emissions:
- burn **biofuels** instead of fossil fuels
-> **recently living plant biomass** eg. sugar cane
-> are **carbon neutral** -> don't release **carbon** stored away for millions of years like fossil fuels do
- use of **other renewable energy** resources
-> wind, solar, geothermal, and tidal energy
-> cheaper to use
-> no CO₂ released
50
**evaluate** the use of biofuels in reducing climate change
PROS
- **cheaper** than oil
- **carbon neutral** -> don't release carbon stored away for millions of years like fossil fuels do
- **renewable** source
CONS
- **still release CO₂** into atm -> as burned same way as fossil fuels
- lots of **land** needed to **grow biofuels** -> could be used for **food production**-> so **less food** produced
- clearing land for biofuel growth leads to **loss of habitats** / burning produces CO₂
-> **bad for biodiversity**
51
suggest some management strategies for climate change
| **management of conflict between human needs and conservation**
- **reforestation** -> **remove CO₂ from atm** via **p/s**
-> increases **p/s**
-> carbon **captured** and converted into carbon compounds and **stored** in plant tissues in trees
- **biofuels**
-> produced from **biomass** -> can be replanted so **sustainable**
-> carbon neutral
-> use as **alternative to fossil fuels** (which increases atm CO₂)
52
outline the stages of primary succession
1. **pioneer** species **colonise** new land
-> seeds / spores blown by wind and grow
-> abiotic factors are **harsh (no soil)** so pioneer species change these by **dying** and **decomposing** = **humus** = **basic soil** with nutrients
2. basic soil = **less hostile** = more organisms can grow
-> they die and decompose = leads to **soil richer in minerals**
3. richer soil = **larger plants** growing
4. at each stage = **diff plants better adapted** = **out-compete existing plants** -> making them **dominant**
5. leads to **climax community** (biggest and most complex) in a steady state now
53
molecular phylogeny
- **molecular diff / similarities** in **seq of bases in DNA** and **seq of a.a in proteins** (molecules)
- to determine **how closely related species / organisms are**
examples of this: look at ...
- **size of ribososmes**
- **structure** of **cell membrane**
54
explain the difference in primary and secondary succession
- secondary succession **already has soil**
- so pioneer species are **larger** plants
55
explain how peat bogs can be used as evidence of climate change
- pollen **preserved** in peat bogs
- peat bogs accumulate in layers -> so **age of pollen increases with depth**
- pollen only produced by **mature plants** -> so samples only show species that survived the climate
- can **extract pollen** in peat bogs to see which plants they came from
- **climate (eg. temp) affects type of plants growing**
- **changes in pollen** over time **indicate change in climate**
56
explain how geographical isolation of a population can lead to 2 diff species
1. **allopatric speciation**
2. **reproductively isolated** -> **reduces gene flow** / no genetic exchange between pop
3. pop will experience slightly **diff conditions** (eg. climates) on each side of physical barrier
4. pop experience **diff selection pressures** too -> leads to **change in allele freq** -> change in **phenotype freq** -> **diff characteristics** **adv** on each side
5. over time, diff pop beome **genetically distinct** -> so **cannot breed** to produce **fertile** offspring
6. 2 pop now diff species
57
suggest why reproductive isolation may occur
- **geographical** isolation (**allopatric** speciation)
- **random mutations** -> result in changes below
-> cause changes to **alleles** and **phenotypes** that prevent populations **successfully breeding** (**sympatric** speciation)
- **seasonal** changes
-> **diff flowering / mating seasons** OR become **sexually active** at diff times
- **mechanical** changes
-> to **genitalia** prevent successful mating
- **behavioural** changes
-> group of individ develop **courtship rituals** that **aren't attractive** to main pop
58
explain how **reproductive isolation** (with **no geographical barrier** present) of a population can lead to 2 diff species
- **diff env** in same area (eg. **soil pH**)
-> **ecological**
- **behavioural** (eg. diff in **feeding**, communication or social->mating behaviour)
eg. diff feeding grounds (behavioural) = **diff selection pressures** = so over time: diff species
59
genomics
- branch of science -> uses **DNA tech** to ...
- **determine base seq** of organisms **genome**
- and **functions** of its **genes**
allows scientists to make **comparisons** between **diff organisms' DNA**
60
proteomics
- study of **proteins** (size, shape, a.a seq of proteins)
- **seq of a.a in protein** is coded for by **DNA seq in gene**
- related organisms have **similar DNA seq** so **similar a.a seq** in proteins
61
what have scientists learnt through **proteomics** and **genomics** research that **supports** the accepted scientific theory of evolution?
-> **closely related species diverged more recently**
-> **evolution** caused by **gradual changes** in **base seq of DNA**
*proteomics*
- organisms that diverged away from each other more recently have **more similar proteins** as **less time** has passed for changes to occur
*genomics*
- organisms that diverged more recently have **more similar DNA** as **less time** has passed for **changes in DNA seq** to occur
62
**assess** the use of **seed banks** in conserving biodiversity and genetic diversity
***adv.***
- cheaper to store **seeds** than **fully grown** plants
- so **large no. seeds stored** than grown plants as **need less space**
- **less labour** to look after seeds than plants
- seeds **can be stored anywhere** as long as cool and dry -> plants would need **specific conditions from o.g habitat**
- less likely to be damaged by disease / natural disaster / vandalism than plants
***disadv.***
- testing seeds for **viability** -> **expensive** and **time consuming**
- too expensive to store **all types of seeds** and **regularly test** for viability
- may be **difficult to collect seeds** from some plants as may grow in **remote locations**
63
describe how **seed banks** contribute to scientific research and the **conservation of endangered species** and their **genetic diversity**
- store **lots of seeds** from **lots of diff species** of plant
- conserve biodiversity by **storing endangered plants' seeds**
- so if plant becomes **extinct in wild**: **stored seeds used** to grow new plants
- conserve **genetic diversity** by storing **range** of seeds for **some** species with **diff characteristics** (so **diff alleles**)
- seed banks create **cool, dry conditions** for storage so seeds can **store for long time**
- seed banks test seeds for **viability** (ability to grow into plant)
-> seeds are planted, grown and **new seeds harvested to put back into storage**
64
describe how **reintroduction** programmes in zoos and seed banks can conserve biodiversity and genetic diversity
| **adv** of reintroduction
- increases no.s in wild -> conserving numbers OR bring species back from brink of extinction
- could also **help organisms** that **rely** on these plants/animals as **food** OR as part of their **habitat**
- also contributes to **restoring lost habitats** eg. rainforests that have been cut down
65
suggest some problems with reintroduction programmes in seed banks and zoos
- reintroduced organisms could **bring new diseases to habitats** -> **harming** other organisms living there
- reintroduced animals may **not behave** as they would've **if they'd been raised in wild**
-> eg. **problems finding food** / **communicating** with wild members of their species
66
describe how seedbanks contribute to scientific research
- study how plant species can be **successfully grown from seeds** -> helps in **reintroducing** them to wild
- used to **grow endangered plants** used in **medical research** (as new **crops** / **materials**)
-> so we **don't have to remove** endangered plants **from wild**
***disadv.***
-> data may **not be representative of wild plants** ...
-> as **only** studying **plants from seeds in seedbank** limits data to **small interbred pop**
67
describe how zoos contribute to scientific research
- increases **knowledge** about **behaviour, physiology and nutritional needs** of animals ...
- contributes to **conservation** efforts in **wild** (eg. nutritional / reproductive studies)
***disadv.***
-> animals in captivity may **act diff** to those in wild
68
describe how zoos and seedbanks help to **educate** people about conserving biodiversity
educating ppl about endangered species and reduced biodiversity helps raise public awareness
- zoos let ppl **get close to organisms** -> increasing **enthusiasm** for conservation work
- seedbanks provide **training** and **set up local seedbanks** all around the **world**
-> eg. Millenial Seed Bank Project aims to conserve seeds in **o.g country**
69
describe how the **genetic diversity** of a species can be measured using **genotypes**
- sample of organism's **DNA** taken and **base pair seq analysed**
- diff **order** of bases for diff **alleles**
- by **sequencing DNA** of **individ** of **same species** -> look at **similarities / diff** in **alleles** within species
- measure **no. diff alleles species has** for **one phenotype** -> to see how genetically diverse species is
-> **more** diff alleles = **greater** genetic diversity
- also look at **heterozygosity index**
= no. heterozygotes ÷ no. individ in pop
70
how is **species diversity** in a habitat measured?
(4 marks)
***RANDOM SAMPLING*** -> measuring **distribution** of organism in area
1. **sample of pop taken**
2. to **avoid bias**: sample must be random (use **rando no. generator for coordinates**)
3. count **no. diff species** (species richness) and **no. individ of each species** in sample area ...
-> plants: **quadrat** **(% cover** to measure abundance)
-> flying insects: **sweepnet**
-> ground insects: **pitfall trap**
-> aquatic animals: **net**
4. use **index of diversity** to calc **species diversity**
5. **repeat** process -> take as many samples as possible (gives **better indication of whole habitat**)
71
explain how the **niche** concept accounts for **distribution** and **abundance** of organisms in a habitat
(2 marks)
abundance
- 2 species occupy **similar niches** will **compete** (eg. for food) = **↓ individ of each species** able to **survive** in area
distribution
- organisms can **only exist in habitats** where **all conditions that make up their role** (niche) **exist**
72
sampling can be random or non-random. random sampling removes bias from results.
suggest why **non-random sampling** is used.
- used in habitats when there is **lot of variety** in **abiotic factors and/or distribution** of species ...
- so want to make sure **all diff areas/species** are **sampled**
73
describe **systematic sampling** and when to use it
samples taken at **fixed intervals**, along a line (using **transect**) - interrupted transect
to see how **organisms (plants) are distributed across an area**
- **line** transects -> taper measure placed along transect and species that touch tape recorded
- **belt** transects -> data collected along transect using frame quadrats next to each other
- **interrupted transects** -> measurements at set intervals (eg. point quadrats every 2m)
74
how to measure diff **abiotic factors** in a habitat
1. climate
-> rainfall: **rain gauge** vol of H₂O collected over period of time
-> humidity: **electronic hygrometer**
2. O₂ availability: **O₂ sensor** (aquatic env)
3. light inensity: **light sensor**
4. soil conditions
-> pH: **indicator** with colour change
-> moisture content: mass soil before and after being **dried out in oven**
5. topography (earth's surface)
-> height reading using **GPS**
-> slope angle: **clinometer**
-> aspect (direction slope facing): **compass**
75
describe how the scientific community critically evaluates new theories
- scientific journals
- peer review
- repeat experiments to **ensure validity**
76
explain why diff ecosystems have diff climax communities
(3 marks)
temperate climate
- lots of **water**, **mild temp** and **not much change in seasons**
- climax community: **large trees** as they can grow in these conditions once **deep soil developed**
polar climate
- **not much water** available, low temp and **extreme changes in seasons**
- large trees **cannot ever grow** in these conditions -> so climax community **only herbs/shrubs**
77
suggest how succession can be prevented and the name of this type
human activities
-> when **succession stopped ARTIFICIALLY** like this = climax community is called a **plagioclimax**
eg. **mowing grass**
-> **larger plants cannot establish** themselves
-> longer interval between mowing = **further** succession can **progress** = *↑ diversity*
-> only **grasses** can survive mowing
78
suggest why NPP might be lower than normal
- when its **cold** / **not lots of light** (usually winter) ...
- as **p/s is slower**
79
NPP also referred to as ...
**energy fixed as biomass**
80
**% efficiency** from one trophic level to the next
NPP of **next trophic level**
÷
energy received (**NPP first level**)
| and **x100**
81
explain why **measuring the diff in energy between 2 trophic levels** is not always **accurate**, including steps to make it more accurate
**consumers** (eg mice) might have **taken in energy from other sources** than **producer** measured (eg. wheat)
more accurate? -> include **all individ organisms** at **each trophic level**
82
explain how you would measure **energy transfer between trophic levels**
(4 marks)
- calc **diff** between **NPP** of each level
- find **NPP** by measuring **dry mass** (biomass) of organisms
-> as ***energy stored as biomass*** so indicates **how much energy organism contains**
- dry organisms in **oven at low temp** -> **weigh** sample **every day** until **mass is constant** = all H₂O removed
- **multiply** results from sample by **size total pop**
- diff energy between trophic levels = **amount energy transferred**
83
how to calc the **average growth rate** of seedlings?
| cm / day
**av. change in height** in each tray
÷
incubation period
84
Q₁₀
rate of reaction at ↑ temp (40℃)
÷
rate of reaction at ↓ temp (30℃)
85
describe a procedure for measuring the **initial rate** of a **catalase-catalysed reaction**
(4 marks)
1. boiling tubes with **same vol + conc H₂O₂** (+ same vol **buffer** sol for neutral pH)
2. set up equipment -> boiling tube + **water trough** with **upside down measuring cyclinder** connected with delivery tube
3. put each boiling tube in **diff temp water bath** (**10, 20, 30, 40, 50℃**) along with another tube with **catalase** (enzyme that catalyses **breakdown of H₂O₂ -> H₂O + O₂**) wait 5 mins
4. use **pipette** to add **same vol + conc catalase** to each boiling tube -> quickly attach **bung + delivery tube**
5. record **how much O₂ produced** (in measuring cyclinder) **every 10 secs** for **1st min**
