Biodiversity

Question 1

What is biodiversity ?

Answer 1

A measure of the variety of living organisms with a particular habitat, ecosystem, biome or all over earth

Question 2

Differentiate between species richness and species evenness

Answer 2

Species richness = The number of species in an area
Species evenness = The number of individuals in each species

Question 3

Discuss different types of sampling

Answer 3

Random = No particular system, however aim is still be representative
Opportunistic = Picking and choosing sampling locations based on various non-random factors
Stratified = Population divided into smaller groups based on a characteristic, then sampled
Systematic = Follows a particular pattern

Question 4

Why is sampling important ?

Answer 4

We cannot study the whole population as it is impractical. Using a representative Sample instead allows us to investigate the population easily

Question 5

Describe how Sampson’s index of Diversity is used

Answer 5

A measure of the relationship between the number of different species in a habitat (species richness) and the number of individuals within each species (species evenness).
A high index of diversity means several different
species are equally abundant, whereas a low index
means one or two species dominate over others.

Question 6

How can we assess genetic diversity ?

Answer 6

Proportion of polymorphic gene loci = number of polymorphic gene loci/total number of loci

Question 7

Give factors that affect biodiversity

Answer 7

Population growth
Deforestation for agriculture = Loss of Habitat
Climate change affecting habitats = Organisms aren’t adapted to new climate
Pesticides and Herbicides = Kill undesired animals/plants

Question 8

Give reasons to maintain biodiversity

Answer 8

Ecological = Protecting species, maintain resources
Keystone species
Economic = Reducing soli depletion
Timber + Products
Aesthetic = Protecting landscapes

Question 9

Define Conservation

Answer 9

The protection and a management of species and habitats, in order to maintain biodiversity. Can be in-situ (in an organisms habitat) or ex-situ (outside an organisms habitat)

Question 10

Give examples of in-situ conservation

Answer 10

Marine conservation
Wildlife reserves

Question 11

Give examples of ex-situ conservations

Answer 11

Seed banks
Botanic gardens
Zoos

Question 12

Give some agreements made with the aim of protecting species and habitats

Answer 12

Convention on international Trade in Endangered Species (CITES) - Regulating international trade of animals

Countryside Stweardship Scheme (CSS) - Planting hedgerows to increases habits

Question 13

How does Deforestation affect biodiversity ?

Answer 13

• Deforestation ruins habitats resulting in loss of shelter, food, water, and other resources that other organisms need to survive
• Loss of habitat causes extinction, different species in the ecosystem die leading to loss of biodiversity which puts the ecosystem in a state of poor biological health.
• Loss of trees leads to soil erosion, tree roots hold soil in place. Without tree roots, rain and wind can remove the soil from the area. This leads to loss of nutritional value of the soil, which impacts the growth of plants, which in turn impacts the entire ecosystem.

Question 14

How can Pesticides and Herbicides affect biodiversity ?

Answer 14

Pesticides and herbicides kill pests and weeds. Pesticides kill undesired animals (pests), and herbicides kill undesired weeds.
Pesticides can kill other animals. Intensive farming often uses pesticides which are toxic to other organisms within the ecosystem.These pesticides can get into the ground and can be carried to nearby river systems by rain water, where they can affect fish and other aquatic animals.
Herbicides can kill other plants, aside from weeds, which educes biodiversity of plants. It also affects any animals that rely on weeds for food

Question 15

What is eutrophication ?

Answer 15

Excessive plant and algal growth due to the increased availability of one or more limiting growth factors needed for photosynthesis

Question 16

How do Fertilisers lead to Eutrophication ?

Answer 16

• Fertilisers used by farmers provide nutrients to help farmers promote good crop growth.
• Fertilisers are carried by rain water to nearby bodies of water.
• Overgrowth of plants removes oxygen from the water.
• Ultimately, eutrophication leads to large scale die off of aquatic organisms, and eventually the plants themselves

Question 17

What is Selective Breeding ?

Answer 17

Selective breeding means choosing plants and animals with the best traits (e.g. most food producing) and breeding them more. However, this leads to a loss in genetic diversity of farm animals, which leads to a loss in biodiversity.

Question 18

How does Conservation and Farming lead to Biodiversity ?

Answer 18

• Loss of genetic diversity increases susceptibility to disease, that can wipe out large numbers of plants and animals, resulting in severe food shortages.
• Soil erosion due to farming can affect nutritional quality of soil. eventually leading to a shortage of food once the soil is nutritionally wasted.

Question 19

What effects does climate change have on the ecosystem ?

Answer 19

• Organisms aren’t adapted to the new climate. Many plants and animals require very specific climates in order to survive. Changing the climate results in a loss of suitable habitat which can cause these organisms to become extinct.
• Certain organisms can outcompete. Organisms better suited to warmer temperatures can outcompete other animals for resources and habitats, which also results in a loss of biodiversity.
• Increase in diseases. Climate change can promote the proliferation of many disease-causing organisms such as mosquitoes, mould, viruses, bacteria, and other parasites. This can harm not only other plants and animals, but also humans.

Question 20

What is Continuous Variation ?

Answer 20

Continuous variation involves features that have intermediate values along a range, there are no distinct categories e.g. height can vary and be any value in a range.

Question 21

What is Discontinuous Variation ?

Answer 21

Discontinuous variation involves features that have distinct categories, with no individuals in between. For example, eye colour only has a few variants: black, brown, green, blue.