Oceans Part 2

Topography of land refers to:

• the physical features and shape of the land surface

• the climate of a region

• the types of plants found in an area

• the population density of a place

Features of the seafloor that are related to plate tectonic processes include:

• mid-ocean ridges, trenches, seamounts, and fracture zones

• coral reefs, sandbars, lagoons, and atolls

• estuaries, deltas, beaches, and bays

• icebergs, fjords, glaciers, and ice shelves

The oceans are an important source of:

• food and minerals

• desert sand

• mountain rocks

• freshwater lakes

What percent of the Earth's oxygen is produced in the ocean?

• About 20-40%

• About 10%

• About 50-80%

• About 90%

Photosynthesis in the ocean is carried out by phytoplankton. Phytoplankton is a form of:

• algae

• fish

• crustacean

• mollusk

Even though the ocean produces 50-80% of the world's oxygen, most of it is consumed by:

• marine life

• the atmosphere

• land plants

• volcanic activity

What do marine (aquatic) animals utilize oxygen for?

• respiration

• digestion

• movement

• reproduction

Additionally, oxygen is consumed during:

• the decomposition of dead marine plants and animals

• the formation of sea ice

• the evaporation of seawater

• the absorption of sunlight by water

So how much of the oxygen that the ocean produces actually helps us to breathe?

• It does not contribute a significant amount to the oxygen humans breathe

• It provides almost all of the oxygen we breathe

• It provides exactly half of the oxygen we breathe

• It provides no oxygen at all

What is an example of a human activity that negatively affects the oceans?

• waste disposal, construction, agriculture, pollution, or overfishing

• swimming in the ocean

• sailing for recreation

• studying marine life