Plant Bio Lecture 12

Primary root

The first main root that grows from a seed and develops downward into the soil.

Taproot

A large, main central root that grows downward, with smaller side roots branching off.

Fibrous root system

root system with many thin, similarly sized roots and no single main root.

Adventitious root

A root that grows from a stem, leaf, or other non-root tissue instead of from the primary root.

Root cap

A protective covering at the tip of a root that protects it as it grows through the soil.

Zone of cell division

Area near the root tip where cells rapidly divide, producing new cells for root growth.

Apical meristem

Region of actively dividing cells at the tips of roots and shoots that causes the plant to grow longer.

Zone of cell elongation

Area of the root where new cells grow longer, causing the root to increase in length.

Zone of cell maturation

Area of the root where cells develop into specialized cell types and root hairs form.

Epidermis (root)

The outermost layer of root cells that protects the root and absorbs water and minerals from the soil.

Cortex

Layer of cells between the epidermis and vascular tissue that mainly stores food and transports water inward.

Endodermis

The innermost layer of the root cortex that controls what enters the vascular tissue.

Casparian strips

Waterproof bands in the endodermis that control the movement of water and minerals into the vascular tissue.

Pericycle

A layer of cells just inside the endodermis that produces lateral (branch) roots.

Vascular cylinder

The central part of a root containing the xylem and phloem, which transport water, minerals, and sugars.

Pneumatophores

Specialized aerial roots that grow upward from waterlogged soil to help the plant take in oxygen.

a) 31 days

b) 45 days

c) 80 days

label # of days in development

prop rood

adventitious

what is this

long root system

what do these trees have

rye

fibrous root system

what is this

what does it have

mucilage on root cap

what is this

endodermis

what has cells that can absorb what they want

pericycle

where do lateral roots form from

mycorrhizal fungi

gray stuff is the fungus

what is this

what is the gray stuff

pneumatophores

what grows above the highest high water level so even when submerged, air roots can get oxygen in and CO2 out

epiphytic root

grows on another plant

what kind of root

what does that mean

horse chestnut buds

showing growth of what

woody stem

what kind of stem

vascular cambium + cork cambium

what two tissues is in woody stems

vascular cambium

tissue that produces new xylem and phloem each year

A- cuticle

B- upper epidermis

C- palisade mesophyll

D- spongy mesophyll

E- vascular bundle

F- guard cells

G- stoma

label

A- petal

B- anther

C- filament

D- sepal

E- ovule

AB- style

AC- stigma

label