abeka biology 10 section 4.5

test (9/15) gl asjksjksja

taproot

penetrate the soil with relatively little branching; commonly found in *dicots*

primary roots

what’s another word for “taproot”, because they grow directly from the plant embryo?

fleshy roots

taproots that enlarge to store large quantities of food

* carrots
* beets
* dandelions

what are some examples of fleshy roots?

fibrous roots

have no main section but spread out with very thin roots, forming a tangled mass in shallow soil

adventitious roots

arise fro

epidermis

protective layer which helps protect the plant and prevent water loss

root hairs

finger-like projection of epidermal cells that increases the water-absorbing surface area of a plant root

root cortex

region of a plant root where food is stored

central vascular system

contains xylem and phloem tissues (surrounded by the cortex); also called the stele

* xylem
* phloem

**two answer fill in the blank**

\
vascular cylinder contains *________* tissues, which carry water to the stem, and *_________* tissues, which carry food back to the root

apical meristem

main growing region near the tip of the root; responsible for forming the epidermis, cortex, and the vascular cylinder

three

**fill in the blank**

\
the increase in length of the root is observed in _______ different regions of the root tip

meristematic region

region closest to the end

region of elongation

cells increase in length, pushing the root further into the soil

maturation region

cells organize into the vascular cylinder; root hairs grow from the epidermal cells in this region

root-cap

cone-shaped structure that covers and protects the tip of a plant root

vascular cambium

growth layer of meristematic cells located between the xylem and phloem

cork cambium

formed beneath the epidermis; replaces the epidermis and forms a tough, protective layer of cork that also prevents the roots from absorbing water

lateral root

root that originates from the taproot; secondary root

permeable

certain substances are allowed to pass through the membrane

diffusion

process of mixing molecules of one substance through another by random molecular motion

semipermeable

allows some substances to diffuse through it but not other substances

osmosis

one-way diffusion through a semipermeable membrane

sap stream

upward flow of water and minerals through the xylem

root pressure

the osmotic force that helps move water to the vascular cylinder

capillarity

upward movement of liquids through a very narrow tube

adhesion

attraction of water molecules to the surface of the xylem tubes

cohesion

attraction to each other

transpiration pull

chief force that draws water up the stem