Unit 3, Topic 1: Describing Biodiversity

Question 1

Recognise that biodiversity includes…

Answer 1

the diversity of species and ecosystems

Question 2

Determine the diversity of species using measures such as…

Answer 2

• Species richness (no. species present)
• Relative species abundance (evenness)
• % cover
• % frequency
• SDI

Question 3

The formula for SDI is…

Answer 3

1 - (sum of n(n-1)) / N(N - 1))

Question 4

What are the four species interactions?

Answer 4

Predation, competition, symbiosis, disease

Question 5

Explain how environmental factors limit the distribution and abundance of species in an ecosystem.

Answer 5

• factors such as predation, competition, and disease from overpopulation can limit this

Question 6

What are is the hierarchial order of the Linnaean classification system?

Answer 6

Kingdom, Phylum, Class, Order, Family, Genus, Species.

Question 7

three main classification systems are based on what?

Answer 7

Linnaean system (similarity of physical features)
Methods of reproduction (asexual, sexual, K and r selected)
Molecular sequences - Clades

Question 8

Define the term clade

Answer 8

A group of organisms that consists of a common ancestor and all its lineal descendants

Question 9

What are the three common assumptions of cladistics?

Answer 9

A common ancestry, bifurcation (diverged from main) and physical change

Question 10

What are the three different species concepts and what do they mean (multiple definitions needed as not all specied fit one)?

Answer 10

• biological species concept (ability to produce viable and fertile offspring)
• morphological species concet (physical similarities )
• phylogenetic species concept (evolutionary relatedness)

Question 11

What is one example of an interspecific hybrid that does not produce fertile offspring?

Answer 11

Mules (from female horse and male donkey)

Question 12

What is the main difference between primary succession and secondary succession?

Answer 12

Primary succession - starts from absolutely nothing, rock

Secondary succession - starts from soil

Question 13

why is the process of classifying ecosystems important for ecologists?

Answer 13

it is a crucial step towards effective ecosystem management e.g. when it may be endangered

Question 14

If a question asks you to describe the process of stratified sampling, you must discuss… (6)

Answer 14

• purpose (population estimation, density, distribution)
• choice of ecological surveying technique (quadrats/transects)
• how to take into account site size
• how to minimise bias (size and no. of transects, random-number generator, the precision of equiptment/technique)
• methods of data presentation and analysis (line graphs)
• analysis of data (standard deviation)

Question 15

what are the three subcategories of symbiotic relationships?

Answer 15

commensalism, parasitism, mutualism