Question

Decomposers such as fungi and bacteria are vital to the ecosystem because of they

	a.	are the primary organic recyclers.
	b.	are the terminal energy consumers.
	c.	keep populations in check.
	d.	help to lower greenhouse gases.

1 points   

QUESTION 5

Which of the following will not be a result of global warming?

	a.	Global temperatures will continue to rise because of increased carbon dioxide levels.
	b.	The acidification of the oceans will continue and will affect marine life.
	c.	Severe weather will increase because of rising temperatures.
	d.	Species with narrow habitat tolerances will outcompete species with broader tolerances.

1 points   

QUESTION 6

The annual increase in carbon dioxide results from two human activities. Burning fossil fuels accounts for _____ percent of the increase, and deforestation causes the remaining _____ percent.

	a.	30; 70
	b.	40; 60
	c.	50; 50
	d.	75; 25

1 points   

QUESTION 7

In the nitrogen cycle, which of these organisms convert atmospheric nitrogen gas into a form that can be utilized by plants?

	a.	Bacteria
	b.	Consumers
	c.	Decomposers
	d.	Omnivores

1 points   

QUESTION 8

Fertilizer runoff into ponds and lakes

	a.	reduces soil nutrients at the bottom of the pond.
	b.	benefits organisms in the pond by decreasing NPP.
	c.	causes aerobic bacteria to deplete available oxygen.
	d.	increases the available oxygen in the pond.

1 points   

QUESTION 9

All life on Earth, except the life in deep sea vent and hot spring ecosystems, depends on ________ energy.

	a.	solar
	b.	synthetic
	c.	chemical
	d.	heat

1 points   

QUESTION 10

The majority of the energy available in an ecosystem is actually ________ as heat energy.

	a.	gained
	b.	recycled
	c.	reabsorbed
	d.	transformed

Answer 1

4) A. Are the primary organic recyclers. They are also known as decomposers as they decomposers the dead planted and animals and bring to the nutrients and energy back into the good chain and hence are the primary organic recyclers.

5) D. The species with narrow tolerance can't withstand the change in the climatic condition and hence will be outcompeted by broad tolerant species.

6) D.

7) A. Bacteria like cyanobacteria, Azetobacter, clostridium etc help in nitrogen fixation.

8) C. It causes eutrophication and the biomass of plants increases, leading to increase in dead planted in the phone. The bacteria decompose this at the cost of dissolved oxygen. Hence the the BOD increases... Causing the depletion of oxygen.

9) A. The solar energy is the ultimate form of energy from which other energy is derived. Deep sea life depende on infrared radiations for energy derivation.

10) D