Answer ALL questions.
1. Define the term sampling.(3)
Sampling is a method used to determine population size, relationships
between organisms and their environment or interactions organisms have
within their community. It is done by extracting a small quantity of a species
for research or in other words taking a sample from the ecosystem.
2. Discuss what you understand by the term “ecological succession”. (4)
Ecological succession is understood by me to be a process in which
organisms inhabit an area and overtime change the state of the environment
thus resulting in the original occupants to be replaced by other species.
3. Explain four (4) actions of humans that may affect species diversity. (10)
Four human actions that affect species diversity are: loss of habitat,
pollution, exploitation and habitat fragmentation. Habitat loss is the
complete destruction of a habitat, such as cutting down trees in a forest.
Pollution of water bodies can result in decrease in oxygen content and harm
fish and other aquatic species and cause a loss of plant biodiversity.
Exploiting can lead to depletion of resources and put a number of threatened
and endangered species at risk of extinction.Habitat fragmentation is
described as a habitat that is broken into smaller discontinuous segments of
land for development, an example of this would be placing a road in the
middle of a habitat.
4. Examine the impacts of a non-native introduced species to a new
environment.(8)
Non-native or invasive species in a new environment negatively impacts the
original wildlife. Non-native species may not have any natural predators or
controls. It can also breed and reproduce quickly, thus dominating the new
environment. Native organisms also have not evolved a defense mechanism against
the non-native species, or they may not be able to compete with a species that has
no predators. The direct threats of invasive species include preying on native
species, outcompeting native species for food or other resources, causing or
carrying disease, and preventing native species from reproducing or killing a native
species' young.
TOTAL
25 MARKS