Environmental Systems 1st 6 Weeks Exam

Based on the information above, why would a farmer want to use phosphate during the growth of winter wheat?

• To increase the nutritional content of the wheat
• To decrease the amount of fertilizer used to grow wheat
• To increase the sale value of each acre of wheat grown
• To decrease the amount of time needed to harvest

What conclusion can be drawn from the graphic below?

• Community B developed into Community A after a period of 50 years.
• Community C replaced Community D after a period of 100 years.
• Community D is the most stable community.
• Community E is the most stable community.

Which of these is the best conclusion that can be drawn from the section marked X in the graph above?

• The population has reached the carrying capacity of its environment.
• The population will soon crash and drop back to its original number.
• The carrying capacity has been severely lowered by drought.
• The carrying capacity will drop over time.

Which level of producers or consumers would be MOST affected by trace amounts of pesticides like DDT that run off into lakes, streams, and ponds?

• Freshwater Algae
• Small Crustaceans
• Sunfish
• Great Blue Heron

According to the information above, which of the following is an ecological consequence of the introduction of the brown tree snake to Guam?

• Tree snakes destroy the habitat of the native birds.
• Tree snakes will soon reach their carrying capacity as their numbers increase to above what the environment can support.
• Guam will have a more balanced ecosystem if it has only one large predator with no natural enemies.
• The introduced species has increased the biodiversity of the region.

The prickly pear cactus was originally imported into eastern Australia in the 18th century for gardens and was later used as natural agricultural fencing. The cactus quickly became widespread, eventually covering 101,000 sq mi (260,000 km ) of farming land in a 20 ft high jungle of cactus. Farmers were forced to leave their homes as their land was overgrown. In 1925, a moth from South America whose larvae eat the cacti was introduced. The moths eventually wiped out the cactus population, returning the land to its normal balance. According to the above information, which of the following statements is not a possible consequence of introducing a foreign moth?

• The moth could have further altered the food chain by eating native plant species besides the prickly pear.
• The moth could have failed to control the prickly pear cactus in this ecosystem.
• The moth could have brought diseases from South America to other insect populations.
• The moth could have mutated the prickly pear cactus.

What role might the newly established eucalyptus forest play in this ecosystem?

• Food source
• Shelter
• Erosion control
• Increased biodiversity

Refer to the above image and dichotomous key. A student attempting to identify a conifer sample notices that it contains needle-like leaves. What should the next step be in identifying the organism?

• Count the number of needles in the bundle.
• Determine the color of the needles.
• Determine the length of the needles.
• See if needles are attached singly or in bundles / clusters.

Honeybees feed on and pollinate clover and flowering plants native to the prairie grassland biomes of Texas. Which of the following organisms provides a similar niche in the Sonoran Desert ecosystem of Arizona?

• Producer – The ironwood tree provides shelter and shade for many desert animals.
• Primary Consumer – Long-nosed bats feed on saguaro cactus blooms.
• Secondary Consumer – The black kingsnake is a constrictor that feeds on small rodents.
• Tertiary Consumer – The spotted owl feeds on small birds.

An average of 2 billion gallons of water is used each day for golf course irrigation in the US. Which of these changes would best aid in reducing the amount of water used for irrigation?

• Use only potable water sources
• Use less fertilizer
• Plant many broad leaf trees
• Utilize native plants and grasses