Biodiversity, Classification and Conservation

Define the biological species concept

Define the biological species concept

A group of individuals that interbreed to produce fertile offspring

Define morphological species concept

A concept that classifies species by their morphological similarities not by their ability to reproduce or their DNA

Define the ecological species concept

In this concept, a species is a group of organisms that are adapted to a particular niche in an ecosystem

Lists the levels of taxonomic classification

• Domain

• Kingdom

• Phylum

• Class

• Order

• Family

• Genus

• Species

Outline the main features of the domain Archaea

• Prokaryotic cells

• DNA is circular, most have histones, has plasmids

• Cell wall present

• Do not have organelles

• 70S ribosomes

Outline the main features of the domain Bacteria

• Prokaryotic cells

• DNA is circular, has plasmids

• Cell wall made of peptidoglycan

• Do not have organelles

• Ribosomes have prokaryotic and eukaryotic features, transcription is similar Eukarya

Outline the main features of the domain Eukarya

• Eukaryotic cells

• DNA is linear and found within the nucleus, histones are present

• Cell wall present in plants and fungi

• Cells have organelles

• 80S ribosomes

Outline the main features of Protoctista

• Multicellular

• Cellulose cell wall

• Autotrophic nutrition

Outline the main features of Fungi

• Mainly multicellular

• Cell wall made of chitin

• Heterotrophic nutrition

Outline the main features of Plantae

• Multicellular

• Cell wall made of cellulose

• Autotrophic nutrition

Outline the main features of Animalia

• Multicellular

• Do not have a cell wall

• Heterotrophic nutrition

Why are viruses not included in any of the three domains?

Viruses are acellular and do not share any characteristic features with cells in the domains

How are viruses classified?

Viruses are grouped according to their nucleic acids e.g. RNA or DNA, double stranded or single stranded

What is meant by the term ecosystem?

The community of organisms (biotic) and non-living (abiotic) components of an area and their interactions

What is meant by the term ‘niche’?

Describes how an organism ‘fits’ into an ecosystem and its role in that environment

What is biodiversity?

Biodiversity refers to variation of living organisms

List three levels at which biodiversity can be considered?

• Variation of ecosystems or habitats

• Number and abundance of species

• Genetic variation within a species

Why is random sampling important for investigating biodiversity in an area?

It avoids bias, which makes the results more reliable

Describe how random sampling and frame quadrats can be used to asses the abundance of species

1. The study area is divided into a grid

2. A random generator is used to obtain coordinates

3. At the coordinates, the frame quadrant is placed on the ground and the abundance of the species in the quadrant is recorded

How can the abundance of a species within a quadrant be estimated?

• The number of organisms within the quadrant can be counted

• The percentage cover can be estimated (useful for species that are very abundant)

When is it appropriate to use transects rather than random sampling of an area?

Transects are used to measure the changed in abundance and distribution of species across a habitat only. A gradual change in an abiotic factor often causes the change in species abundance

Describe how systematic sampling and a belt transect can be used to assess the abundance and distribution of species

A belt transect is drawn from one part of a habitat to another. The frame quadrat is placed at regular intervals along the belt transect and the abundance of a species is measured

Describe the difference between a line transect and a belt transect

• Line transect - all organisms touching the line are recorded

• Belt transect - only organisms in the frame quadrant at each interval are recorded

What method is used to investigate populations of motile organisms?

Mark-release-reacapture

Outline the mark-release-recapture method

A group of organisms of the target population are caught, counted and marked

The marked organisms are released back into the habitat

After a period of time, organisms of the same population are captured again

The proportion of marked to unmarked organisms in the captured group is assumed to be the same as the proportion of marked to unmarked in the whole population

Estimated population size = (number of individuals in first samples x number of individuals in second sample)/number of marked individuals in second sample

How is Spearman’s rank correlation coefficient used in investigations of species populations?

Spearman’s rank tests whether there is a correlation between two data sets e.g. to see if there is a correlation between distribution of organisms and an abiotic factor like soil pH

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

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

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

Explain what the value of D mean for Simpson’s Index of Diversity

D is the index of diversity. A high value for D means there is a lot of diversity, so species richness and species evenness is high

Outline the threats to biodiversity in ecosystem

Some of the threats include climate change, deforestation and destruction of habitats, pollution, introduction of new species and hunting by humans

Why does biodiversity need to be maintained?

• To maintain stable ecosystem

• Ethical reasons

• Aesthetic reasons

• Many plant species are yet to be discovered and may contain chemicals that could be used in future medicines

List methods of protecting endagered species

• National parks

• Zoos

• Botanic gardens

• Frozen zoos

• Seed banks

Give examples of methods of assisted reproduction for conservation efforts

• In vitro fertilisation (IVF)

• Embryo transfer

• Surrogacy

State what is meant by an ‘alien species’

An alien species is one which is living in a habitat it is not native to. The species may arrive there intentionally or unintentionally

What effects can alien species have on a habitat?

• An alien species represents a new competitor for resources, they may outcompete native species resulting in extinction

• The alien may be a predator for the native species

• The alien species may bring new diseases into the habitat

What is the role of the World Wide Fund for Nature (WWF)?

WWF is a non-governmental organisation.

It aims to conserve biodiversity on a global level, protect and restore ecosystems , promote the use of sustainable resources and reduce pollution and waste

What is the role of Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES)?

CITES is an agreement between governments

It regulates wildlife trade to ensure it is not a threat to their survival and it prevents overexploitation of resources, particularly of endangered species