photosynthesis
	respiration
	transpiration
	oxidation
	carbonation

	magnesium
	nitrogen
	carbon
	potassium
	phosphorus

	All the nutrients required for plant growth have already been found.
	It is very difficult to prove that a plant needs a certain nutrient.
	Plants need thousands of nutrients; a new one is not significant.
	Any nutrient needed in large amounts (macronutrient) has probably been noted already.
	Plants manufacture their own macronutrients.

	copper
	molybdenum
	sulfur
	magnesium
	phosphorus

	phosphorus
	magnesium
	manganese
	iron
	sulfur

	sulfur
	phosphorus
	nitrogen
	potassium
	iron

	oxygen
	phosphorus
	carbon
	iron
	hydrogen

	Deficiency symptoms of freely moving nutrients will show up first in younger organs.
	Deficiency symptoms of immobile nutrients will show up first in older organs.
	Mobile nutrients are drawn to growing tissues; therefore, growing tissues would not show signs of mineral deficiency of mobile nutrients before older tissues.
	Symptoms of mineral deficiency always show up in older leaves first.
	Symptoms always show up in younger leaves first.

	sugars
	complex carbohydrates
	vitamins and amino acids
	minerals
	all of the above

	potassium
	calcium
	magnesium
	nitrate
	ammonium

	are composed of nitrogen needed by plants
	eliminate spaces for air and facilitate drainage
	fill spaces and keep oxygen out of the soil
	are charged and hold ions needed by plants
	supply humus needed by plants

	iron, manganese, and zinc
	calcium and boron
	nitrogen, phosphorus, and potassium
	molybdenum, copper, and magnesium
	all essential nutrients

	to test whether an element is essential to a certain species of plant
	to replace lost minerals in soil
	to clean contaminated sites by using plants that have the ability to extract and store soil pollutants
	to grow crops such as alfalfa and wheat that provide good ground cover
	The second and third answers are true.

	The pH level of soil affects anion exchange and influences the chemical form of minerals.
	The pH level of soil affects cation exchange and influences the chemical form of minerals.
	The pH level of soil affects water levels.
	Plants may turn blue if the pH is too high.
	None of the above.

	hydrogen
	carbon dioxide
	nitrogen
	oxygen
	neon

	using nitrogen to build molecules such as proteins and nucleic acids
	converting nitrogen in the air to a form usable by plants
	recycling nitrogen from organic matter in the soil
	absorbing N2 from the soil
	performed by fungus inhabiting root nodules

	rhizobium
	nitrogenase
	nodulase
	rubisco
	hydrogenase

	contain nitrogen-fixing bacteria
	form fungal hyphae
	provide a steady supply of sugar to the host plant
	produce antibiotics that protect the plant from soil bacteria
	increase the surface area for water uptake

	In plants, nod genes cause the secretion of flavonoids.
	In Rhizobium, nod genes produce enzymes that catalyze production of Nod factors.
	In plants, nod genes cause the formation of mycorrhizae.
	In Rhizobium, nod genes cause the secretion of flavonoids.
	Currently, no one has determined what the role of nod genes is in this relationship.

	when nutrients are required by plants in relatively small amounts
	in plants such as mistletoe that parasitize other plants
	when soil is too compact and lacks sufficient air spaces
	to control the evaporation of water from leaves
	between roots and beneficial fungi

	Endomycorrhizae penetrate the cytoplasm of root cells.
	Ectomycorrhizae are found in many crop plants such as wheat and maize.
	Endomycorrhizae do not have a dense mantle ensheathing roots.
	The fungal hyphae of ectomycorrhizae form arbuscules.
	None of the above is correct.

	water ... because they live in dry soil
	nitrogen ... to make sugar
	phosphorus ... to make protein
	sugars ... because they can't make enough in photosynthesis
	nitrogen ... to make protein