biodiversity Flashcards

Question

Disadvantage of stratified sampling

Answer 1

Unusable when you can't classify every member of the population into a sub group.

Answer 2

Different areas within an overall habitat are identified and sampled separately. E.g. May be used to study how plant species change as you move inland from the sea. Often carried out using line/belt transects.

Answer 3

Simply a straight line marked across a habitat. Species that touch the line at regular intervals are identified and recorded. Results are converted into a drawing that shows the distribution of organisms. Used to show how communities change along a gradient. Good way to show the changes qualitatively.

Answer 4

Quantitative Similar to the line transect but gives information on abundance as well as presence/absence of species. Involves placing quadrats along a line taken through an ecosystem Short distance - quadrats placed continuously - continuous belt transect Long distance - quadrats placed at intervals - interrupted belt transect

Answer 5

Method is biased as area you choose to put down in the transect may not be representative of the whole habitat.

Answer 6

More straightforward than random sampling as you don't have to measure the coordinates for each sample.

Answer 7

May occur accidentally or deliberately. E.g. You may choose a particular area to sample because it has more flowers in it or it look interesting. Sampling bias can be reduced/eliminated by random sampling where there is no human involvement.

Answer 8

Organisms selected may not be representative of the whole population. E.g five worms picked at random in a sample may be the longest worms in the populations so the average height taken from this sample would be unreliable. Chance can never be completely removed from the sample but it can be minimised by using larger samples. Greater number of individuals studied=lower the probability that chance will affect the result. Bigger sample=more reliable sample.

Answer 9

- Mutations in the DNA of the organism, creatign a new allele - Interbreeding between different populations .This causes alleles to be transferred between the two different populations - GENE FLOW.

Answer 10

Selective breeding (only a few members of a species are selectively bred for their desired characteristics) Captive breeding programmes Artificial cloning (e.g. cutting from plant) Natural selection - alleles coding for less advantageous characteristics decline drastically from a population or are lost altogether. Genetic bottlenecks Founder effect Genetic drift

Answer 11

Few individuals of a population survive disease/environmental change/habitat destruction. Only their alleles are passed on to the successive generation, reducing the gene pool.

Answer 12

Small number of individuals create a new colony, geographically isolated from the original. the gene pool for this new population is small.

Answer 13

The process of change in the genetic composition of a population due to chance or random events rather than by natural selection, resulting in changes in allele frequencies over time.

Answer 14

A gene with more than one allele

Answer 15

a gene with only one allele

Answer 16

Position of a gene on a chromosome

Answer 17

= high genetic diversity

Answer 18

likely to have some individuals in the population that carries an advantageous allele which enables them to survive a change of conditions. Without these individuals the species will be extinct.

Answer 19

deforestation Agriculture Disease Climate change

Answer 20

- Directly reduces number of trees present in an area. - If only a specific type of tree is felled then species diversity is reduced. - Reduces number of animal species in the area (destroys their habitat and source of food) - Animals may migrate to other areas as a result. this reduces biodiversity of other areas.

Answer 21

- Reduces number of plant species in the area - Destroys habitat of blackbirds, mice, hedgehogs and many invertebrates.

Answer 22

- reduces animal species by killing pest species. By doing this they also kill food sources of other organisms. - Herbicides reduce plant diversity by destroying weeds. Also kills food sources for other animals.

Answer 23

- Lowers plant diversity as only one species of plant is present. - Relatively few animals will be supported by one type of plant, so overall biodiversity decreases. - Monoculture interferes with nitrogen cycle so contributes to soil depletion. -Soil depletion produces weaker crops which are more vulnerable to predators, competitors and disease. -Farmer will become more dependent on pesticides, herbicides and fertilisers.

Answer 24

- Poles of the earth already have low biodiversity. Could lead to exticntion of the few species living there. - Species will migrate towards more favourable conditions. - Rising sea levels reduce habitat diversity be flooding low lying land. -Saltwater flows further up rivers, reducing habitats of freshwater plants and animals.

Answer 25

Insects adapt to climate change. They act as pollinators. If their life cycles change, it could affect the lives of many plant species, leading to extinction.

Answer 26

Non drought resistant species of plants will die out. animals that feed on them will die too. drought resistant plants (xerophytes) will become more dominant. animals that used to feed on hydrophytes will be replaced by animals who feed on xerophytes.

Answer 27

-Will lower biodiversity initially through bottleneck effect. - Eventually genetic drift will cause biodiversity to increase. Different genetic populations will occur as a long term result of disease. Monoculture populations of crops are extremely vulnerable to disease.

Answer 28

Deforestation causes soil erosion and desertification. This reduces a country's ability to grow crops and feed its people - May lead to economic dependence on other countries. Important to conserve raw materials for industry. Non sustainable sourcing of raw materials will make it economically inviable to continue certain industries. Large scale habitat and biodiversity losses will mean species with economical importance may become extinct before they are even discovered. Undiscovered species may be economically or medically useful. High biodiverse areas promotes tourism. Crop yield can be increased by higher plant diversity. Genetically engineered crops may need genes from wild varieties of plants, therefore biodiversity needs to be maintained.

Answer 29

All organisms are independent on others for their survival. Removal of one species may have a significant effect on others. E.g. a food source or habitat may be lost. Keystone species - A species which are essential to maintain biodiversity. They have a disproportionately large effect on their environment relative to their abundance.

Answer 30

All species have the right to exist but may lack the ability to survive in the light of human kind's modifications of the environment. Humankind has the moral responsibility, as the dominant terrestrial organism, for the care and survival of other species.

Answer 31

The natural environment provides an outdoor laboratory for developing a better understanding of the natural world. Such research has often yielded results of direct benefit to humans. (medicines etc)

Answer 32

Maintains genetic diversity of species Maintains evolutionary adaptations that enable a species to adapt continually to changing environmental conditions. Preserves interdependent relationships present in a habitat. Interlinked species may be also be preserved. Cheaper than ex situ conservation. Less disruptive than removing organisms from their habitats. Facilitates scientific research of the site.

Answer 33

Endangered species may be fragmented so the area may not be large enough to ensure the survival of these species. Genetic diversity may have already been dramatically increased. Conditions that threatened the organisms in the area may still be present. E.g disease or interspecies competition. Poachers and ecotourists may see the thriving area as an opportunity and may cause damage. Cannot always provide medical response to animals.

Answer 34

Controlled Grazing - Only allows livestock to graze a particular area of land for a certain period of time to allow species to recover. Restricts human access (paths to allow plants not to be trampled) Controlling poaching - (fines, defences to prevent access) Feeding animals to ensure more survive until reproductive age Reintroducing species to areas where they are locally extinct or in decline Halting succession so that heath-, moor- or downland doesn't all grow into woodland so future generations can enjoy them. This often achieved through controlling grazing.

Answer 35

Organisms are completely protected from predation and poaching Health of individuals can be monitored and medical assistance can be given as required. Population can be more effectively managed and divided if disaster strikes Genetic diversity of the population can be measured Selective breeding programmes can be put into place Modern reproductive technology can increase the chance of reproductive success Research into reproductive physiology, lifestyle can be carried out easier of animals are in captivity. Conservation sites can be used as attractions to raise funds for further conservation efforts. Conservation sites can be used for education.

Answer 36

Captive populations have limited genetic diversity - more susceptible to rapid species decline/extinction with the onset of disease. Organisms are living outside their natural habitat, which could affect their health. Correct survival environmental conditions may be difficult to achieve. Captivity is expensive to maintain. Animals may not survive reintroduction into the wild. Animals may not be accepted into wild species once reintroduced.

Answer 37

- Lasts longer than plants - allows researchers and conservation biologists to evaluate them for properties such as new sources of medicines, nutrition, and genes. - facilitates scientific study that could provide helpful information for conserving the remaining natural populations of the species. - Can control when to plant seed. - Immune to habitat destruction, diseases and predators. - can be used to reintroduce into habitats where they were once present. -Can be used to augment new habitats with low biodiversity.

Answer 38

Countries involved agree to commit to conservation and sustainable use of biodiversity. Every country has to take ownership to protecting its biodiversity. Species can be exploited SUSTAINABLY. Countries choose their own methods for protecting their biodiversity.

Answer 39

Ensures that species trade of flora and fauna arent exploited unsustainably. Appendix 1 -Endangered species/species affected by trade are protected. Appendix 2 - Species not necessarily threatened with extinction but for which trade must be controlled to avoid them being endangered. Appendix 3 -Species for which a country is conserving for it's own reasons are protected.

Answer 40

Provides financial incentives for local farmers to protect their environment such as: - Conserving and restoring wildlife habitats - Flood risk management - Reducing widespread water pollution from agriculture. - Keeping the character of the countryside. - Preserving features important to history of landscape. -Encourages educational access. -Competitive scheme - scored against local priority targets to maximise environmental benefits.

biodiversity Flashcards

(64 cards)