Plant Anatomy

The Root: Secondary Growth & Modifications

Multiple Choice Quiz


1	Secondary xylem in roots is characterized by:
		A)	few and narrow rays.
		B)	lack of parenchyma.
		C)	lack of vessels.
		D)	lack of bordered pits.
		E)	centrifugal development.


2	Vesicular-arbuscular mycorrhizae are most commonly found in:
		A)	ectomycorrhizae.
		B)	endomycorrhizae.
		C)	both.
		D)	neither.


3	Compared with stems, root secondary xylem tends to show:
		A)	wider vessels.
		B)	greater lignification.
		C)	more derived parenchyma cells.
		D)	less amount of parenchyma.
		E)	primary xylem outside of the secondary xylem.


4	In fleshy roots:
		A)	xylem parenchyma may convert to secondary cambia.
		B)	phloem is completely separated from the xylem.
		C)	xylem forms a uniform ring around the root.
		D)	all xylem is replaced by storage parenchyma.
		E)	secondary cambia do not exist.


5	Adventitious roots may form:
		A)	from pericycle.
		B)	from rhizodermis.
		C)	along xylem rays.
		D)	from rootcap.
		E)	from the ground meristem.


6	A velamen is:
		A)	formed inside of an exodermis.
		B)	a multiple rhizodermis.
		C)	characterized by containing a Casparian strip.
		D)	found in underground storage roots.
		E)	composed of densely-cytoplasmic cells upon maturity.


7	What kind of divisions of pericycle can give rise to cambia?
		A)	Anticlinal
		B)	Periclinal


8	The development of branch roots is said to be:
		A)	endogenous.
		B)	exogenous.


9	Phellogen typically originates from:
		A)	pericycle.
		B)	endodermis.
		C)	cortex.
		D)	exodermis.
		E)	rhizodermis.


10	What is an example of a plant that retains its cortex for some time and develops an exodermis or superficial periderm?
		A)	Wheat
		B)	Pine
		C)	Radish
		D)	Corn
		E)	Spruce

2003 McGraw-Hill Higher Education

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