biodiversity

Question 1

define biodiversity

Answer 1

This is the variety of living organisms present in an area including plants, animals and fungi …

Question 2

what are the three levels of biodiversity

Answer 2

habitat - the range of different environments that species can live in. ie meadow, streams, sand dunes and woodland.
species - can be measured in terms of richness (the number of different species) or evenness (how similar each population is)
genetic - the range of different alleles within a population. prevents a species going extinct because they are likely that some will be suited to their environment. a greater area will then be colonised by a species so less likely that they will all be killed by a disease/predator.

Question 3

what is random sampling

Answer 3

This is when each individual in the population has an equal probability of being selected for sampling. ie generate random numbers or coordinated.

Question 4

give some examples of non random sampling

Answer 4

opportunity - using organisms that are conveniently available for sampling
stratified sampling - divinding populations into subgroups based on a characteristic ie male and female. then a random sample is taken from each of these.
systematic - different areas within a habitat are sampled ie using a line or belt transect

Question 5

describe the difference between a line and belt transect

Answer 5

line - mark a line along the ground between two points and take samples at specific points
belt - two lines are draw and samples are taken from the area in between the lines.

Question 6

how can sampling being effected by bias

Answer 6

sampling bias and chance

Question 7

give 5 ways in which animals can be sampled

Answer 7

POOTER - sucking a mouth piece and drawing insects into a holding container
sweep nets
pitfall traps - a whole is dug in the floor which insects can fall into, they then get trapped. covered with a roof structure to ensure no flooding.
tree beatings - a large white cloth is place around the tree, the tree is shaken and animals will fall onto the blanket.
kicking sample - river bank is kick, unsettling the organisms in it and then a net is used to collect organisms down stream.

Question 8

describe how plants are sampled

Answer 8

Using a POINT or FRAME quadrat

Question 9

What is the difference between a point quadrat and framed

Answer 9

point - a frame with a horizontal bars. each species touching the bar is counted
frame - square frame divided into smaller grids and number of species in each section is recorded.

Question 10

describe three ways in which a frame quadrat can be used to measure plants in a habitat

give strength and weakness for each.

Answer 10

DENSITY - count the number of plants indie the 1m quadrat. this gives the density per metre2. -time consuming +accurate
FREQUENCY - (used when an individual species is hard to count ie grass or moss) count how many small grids within the quadrat the species is present in ie 65 squares out of 100. this suggests that the frequency of its occurrence is 65%.
-approximate results +rapid, can be used when individual member of a species cannot be identified
PERCENTAGE COVER - useful when a species is abundant to save time. it is an estimate, using eye, of the area within a quadrat that a species covers.
+lots of data can be collected and fast -less precise, human error

Question 11

how can you increase the reliability of sampling

Answer 11

take lots of samples to reduce the effects of chance of data. .

can calculate the mean to get an average of species per m^2 then multiply by the total area to give the average number of organisms across the whole area.

Question 12

describe the capture mark release technique

Answer 12

it is used to measure the animal population size as animals are constantly moving. individuals are captured, marked and released back into the community. time passes to allow the species to redistribute.

then there is a second set of sampling. you can estimate the population size by comparing the number of marked species with the number of unmarked species.

the greater the number of marked species suggests a smaller population size.

• marks can be rubbed off/fall off.
• can increase a species visibility to predators
• can be dangerous because requires getting up close with wild species.

Question 13

what are abiotic factors and give some examples

Answer 13

non living factors that can have a direct effect on the organsims within an area. ie light and water.

Question 14

which is better - a thermometer or a temperature probe and why.

Answer 14

a temperature probe as it has a higher resolution, can monitor rapid changes, data can be stored on a computer and less chance of human error

Question 15

what is simpson’s index

Answer 15

a measure of biodiversity taking species evenness and richness into account. gives a value between 0-1. 0=low diversity. 1=high diversity

Question 16

describe an environment with a high biodiversity

Answer 16

large number of successful species, ecosystem is fairly stable, complex food web, unlikely to be hostile

Question 17

why is it important to have have high genetic diversity

Answer 17

Species with a high genetic diversity number of different alleles within the population) are likely to be able to adapt to changes in their environment so they are more likely to survive and not become extinct.

Question 18

outline 9 factors that can effect genetic diversity

Answer 18

mutations - change to the bases sequence of DNA
genetic drift - when the frequency of occurrence of an allele is low so the existence will gradually become less and less (small popualtions).
bottle neck - when few individuals of a species survive an event ie natural disaster or environmental change so only a small gene pool.
founders effect - when a small number of organisms create a new colony, geographically isolated from the original.
gene flow - interbreeding between different populations due to migration causing alleles to be transferred between species.
selective breading - few individuals are selected based on advantageous characteristics (and their offspring) reduces the gene pool over many generations.

captive breeding programmes - only a small number of individuals are available for breeding. (often because the population is endangered) reduces the gene pool.
artificial cloning - asexual reproduction using plant cuttings
natural selection - overtime advantageous alleles increase in frequency whilst disadvantages alleles are lost

Question 19

how can you measure genetic diversity

Answer 19

by measuring polymorphism ie a gene that has more then one different alleles existing ie blood type.

most genes are monomorphic to ensure that the basic structure of an organism is consistent.

proportion of polymorphic gene loci =

no of polymorphic gene loci/ total number of loci

the loci refers to the postion of a gene on a chromosome.

the greater the proportion of polymorphic gene loci, the greater the genetic biodiversity.

Question 20

why is it important to maintain biodiversity

Answer 20

food, wood and oxygen
moral obligation
aesthetic reasons - mental health, relaxing, increases recovery time for sick people

economic ie tourism, soil erosion due to deforestation prevent crops from being able to grow leading to not being able to feed people. soil depletion reduced biodiversity of mineral ions in the soil more fragile ecosystem. non renewable resources such as timber, once lost leaves a gap in the industry. some plants can be undiscovered which may have been good medicinal purposes,

ecological reasons - species are interdependent on one another, keystone species.

Question 21

how do humans effect biodiversity

Answer 21

to make room for housing, farming and industry DEFORESTATION occurs - reducing the number of habitats available forcing animals to migrate for their own survival. ie through forest fires, acid rain or deliberate due to human action.

some area forests are now being replaced. however only few commercially viable trees are being planted so there is still low biodiversity.

agriculture - increases monoculture as lots of land is clear to plant one single crop.

deforestation to make space for the land, destruction of hedges to enable the use of large machinery reduces habitats, pesticides and fungicides kill pests that would eat crops (insects) or live on animals. kills pescts and indirectly threatens survival of species who eat pescts.

climate change - release of carbon dioxide into the atmosphere from the burning of fossil fuels increases global temperatures.

causes ice caps to melt and sea levels to rise (saltwater could flow into fresh water reducing habitats for fresh water organism) increase in temperature and less rain fall.

pollution - improper disposal of waste and packaging and release of chemicals into environement.

Question 22

what are keystone species

Answer 22

A species that has a huge impact in the environment and affect many other organisms in the ecosystem. removing the keystone species can lead to reduce biodiversity. essential to maintain biodiversity.

ie alligators make burrows, when they live fresh water fills the space for other species to drink out of.

Question 23

how to humans have a good impact on biodiversity

Answer 23

grazing, farming and planting hedges helps manage environements so that species are able to survive there.

Question 24

define conservation

Answer 24

the preseravtion and careful management of an environment of natural resources.

Question 25

give two types of conservation

Answer 25

In situ - within natural habitat
ex situ - outside of natural habitat

focus on conserving species that are classified as endangered - likely to become extinct.

Question 26

give strengths of in situ

Answer 26

+ maintains genetic diversity
+ maintains evolutionary adaptions to the organisms environment
+preserves the interdependent relationships in the habitat so that other species can be conserved as well
+cheaper

ie marine (saltwater), aquatic (freshwater( and terrestrial (land) nature reserves are examples

Question 27

describe active management techniques in insitu conservation

Answer 27

controlled grazing - allowing live stock to graze but only for a short period of time.
restricting human access ie alternate paths to prevent plants being trampled
controlling poaching - preventing access, issuing fines and removal of rhino horns.
feeding to ensure survival
reintroducing a species back into an environment
culling or removal of invasive species (not native to the area and act as competition)
halting succession.

Question 28

what is succession

Answer 28

this is a natural proces sin which early colonising species are replaced overtime until a stable mature popualtion is achieved.

Question 29

describe some marine conservation techniques

Answer 29

vital to maintain species richness in coral reefs due to unsustainable fishing. quotas, fines.

Question 30

give some examples of exsitu conservation techniques

Answer 30

botanic gardens - species are actively grown in the best most optimum conditions. ie soil quality, nutrients and water.

seed banks - a way in storing new plants which can be grown in the future. stored at 120 to slow down the rate at which they lose the ability to germinate.

captive breeding programmes ie zoos and aquatic centres. aims to make a stable and healthy population of species and then gradually reintroduce them back into their natural habitat. provide shelter, food and protetion as well as veterinary treatment.

overbreeding problems can occur.

Question 31

why may animals born into captive breeding not be suitable to be released bakc into the wild

Answer 31

diseases and resistance, behaviour is not learnt through copying an observations, genetic difference can become so different that they cannot interbreed to produce fertile offspring anyway, habitat most first be restored, if not it can lead to stress and tension as they fight for limited territory.

Question 32

describe the internation union for the conservation of nature

Answer 32

secures agreements between nations to conserve organisms. was involved in the conversion on international trade of endangered species which regukates the trade of wild plants and animals across borders.

Question 33

describe the Rio convention

Answer 33

• countries should develop natural strategies for sustainable development to maintain biodiversity.

agreement to stabilise green house gas concentrations in the atmosphere.

reduce the effects of drought ensuring fertile land

Question 34

outline the country side stewardship scheme

Answer 34

sustaining beauty and diversity of landscapes, improving and extending wildlife habitats, restoring neglected lands.

Question 34

outline the country side stewardship scheme

Answer 34

sustaining beauty and diversity of landscapes, improving and extending wildlife habitats, restoring neglected lands.

Question 35

Outline how the percentage efficiency of energy transfer between producers and herbivores can be estimated.

Answer 35

primary producer/producer energy x100
collect herbivore from same area.
measure biomass (dry mass)
use a calorimeter (burn sample in oxygen measure temp change)