Grade 9 Elite EOT 3 Revision

The graph below shows the increase in temperature and CO₂ levels in the atmosphere over several years. Which of the following factors is most likely responsible for the results in the graph?

• burning of fossil fuels

• planting trees

• recycling plastic

• using less electricity

In the 1980's, scientists began to study and report a process known as eutrophication, which occurs in freshwater lakes. Fertilizer runoff from nearby farms start the process by adding chemical pollutants and/or nutrients to lakes. Primary producers (specific types of plants) benefit from the additional nutrients. The plant layer can become so thick that light cannot penetrate the water. Suggest what will happen if chemical runoff continues to add nutrients to these lakes?

• plant growth will continue, releasing large amounts of oxygen into the water. because fish cannot handle large amounts of oxygen, they will die

• plant growth will continue, releasing large amounts of oxygen into the water. because of the added oxygen, the fish will grow

• plant layers will die and be degraded by microorganisms, removing oxygen from the water. because of the reduction in oxygen, fish will die

• plant layers will die, leaving the lake healthy and the water clear

The image below is an illustration of an estuary. The concentration of salt in different water bodies varies. An estuary has which of these characteristics?

• a highly saline body of water

• an area with varying salinity

• a zero salinity body of water

• a low salinity body of water that enters land

During ecological succession, the earliest organisms to exist are known as __________

• end point species

• primary organisms

• succession plants

• pioneer species

All the following are factors that affect biodiversity, EXCEPT _________

• destruction of habitat

• disruption of habitat

• fragmentation of habitat

• enlargement of habitat

How do forest fires initiate ecological succession?

• forest fires contribute by adding a layer of decomposing organic materials which leads to soil formation and hence ecological succession

• forest fires wipe out all living matter and do not initiate ecological succession

• forest fires do not affect most of the communities in an ecosystem

• forest fires are beneficial to all plants in an ecosystem

what are endemic species?

• endemic species are those that were artificially placed in restricted locations

• endemic species are those which are likely to be extinct

• endemic species are found in a wide range of geographical locations

• endemic species are naturally found in specific geographic areas that are usually restricted in size

An organism's population decreases and eventually disappears as environmental conditions change over millions of years. what does this statement describe?

• pollution

• mass extinction

• eutrophication

• background extinction

The following are characteristics of a river:

i. slow-moving water

ii. nutrients from erosion

iii. water flows into larger body of water

iv. water travels in different directions

• i, ii, iii only

• i, iv, ii

• ii, iv, iii

• i, ii, iii, and iv

Community ecology could be defined as the study of the _____________.

• number of individuals of one species in an area as well as how and why the number of changes over time

• processes and consequences of interactions within and among different populations within the same area

• physiological, morphological, and behavioral adaptations that enable individuals to live in specific habitats

• processes and consequences of interactions within the same species in different areas