mod 4 Flashcards
Beavers were hunted to extinction in the UK about 500 years ago. Recently a trial reintroduction
in Scotland was hailed as a great success after researchers found that the animals had ‘transformed
the landscape’. After five years the beavers had:
* constructed dams – the largest of which was 18 m long and 1.6 m high
* felled trees
* created canals
* built lodges (large nests)
* successfully reproduced.
i.
Beavers are considered to be a keystone species.
Explain why they are a keystone species in their native Canada.
- many species rely on beaver activity
- beavers have a significant effect on the ecosystem
community
All the populations of different species living and interacting in the same area at the same time
ecosystem
The dynamic interaction between all the biotic and abiotic factors in a given area
habitat
The part of an ecosystem where a particular organism lives
niche
The role of an organism within its ecosystem, including its interactions with abiotic and biotic factors
Conservationists often decide which areas they should target based on calculated indices.
Why might a species richness index not be the most useful index to use?
Species richness index does not take into account the population size.
This means that a habitat may appear healthy and diverse but actually contain very few of each species and therefore need conservation
Why might ubiquitin (an essential protein involved in protein degradation) be more useful than haemoglobin when evaluating evolutionary relationships?
Ubiquitin is one of the most highly conserved molecules.
Haemoglobin is not found in a wide range of organisms (e.g. unicellular organisms, plants do not have haemoglobin.
This means that amino acid or DNA sequencing of haemoglobin cannot be used as a comparison for as many species.
