Plants

what are the 3 main components of a seed?

seed coat; storage material; embryo

the \_____ is a hard outer layer that covers and protects the seed from various external forces

seed coat

the \_____ stores nutrients for the embryo in a seed

endosperm

the \_____ refers to the first leaves that appear on a seedling

cotyledon

what are the 4 main parts of the embryo of a seed?

radicle; hypocotyl; plumule; epicotyl

the \_____ is the part of the embryo that develops into the young root

radicle

the \_____ is the first to emerge from the seed coat, and it anchors the plant into the soil

radicle

what makes up the young shoot (things above the soil)?

hypocotyl, plumule, and epicotyl

the \_____ is the bottom region of the young shoot (above the roots but below the cotyledons)

hypocotyl

the \_____ develops into the very top region of the young shoot (shoot tip)

epicotyl

the \_____ is found in between the hypocotyl and epicotyl, and it develops into young leaves

plumule

\_____ is the sprouting of a seedling from a previously dormant seed

germination

seeds remain in a state of \_____ until environmental conditions are suitable for growth

dormancy

what is the most important environmental "cue" that kick starts germination?

water

imbibition

the absorption of water by the seed

\_____ is the growth of a seedling into a more mature plant

development

in plants, growth takes place via repeated cell division/mitosis at the \_____

meristems

what are the 2 types of meristem?

apical and lateral

where are apical meristems located?

the very tips of roots and shoots

\_____ cause the plant to grow vertically

apical meristems

what is the location and function of lateral meristems?

found where horizontal growth can occur

(i.e., lateral meristems function to increase thickness)

lateral meristems include \_____ & \_____

vascular cambium; cork cambium

where does primary growth occur in a new hatchling?

apical meristems

\_____ cover and protect the apical meristem, so the meristem can further penetrate soil

root caps

what are the 3 zones created by apical meristem divisions?

zone of division; zone of elongation; zone of maturation

\_____ is the vertical growth of a plant at its apical meristems

primary growth

(zone of division \= zone of maturation in this picture)

\_____ is the horizontal growth of a plant at its lateral meristems

secondary growth

what is the vascular cambium?

a ring of meristematic tissue located between the primary xylem and primary phloem

cells that are produced on the \_____ of the vascular cambium ring become the secondary xylem

inside

cells produced on the outside of the vascular cambium ring become the \_____

secondary phloem

the \_____ forms wood (along with pith)

secondary xylem

(cells inside the vascular cambium \= secondary xylem)

secondary phloem makes \_____, which is constantly being shed and replaced

bark

the \_____ is a ring of meristematic tissue located beyond the phloem, closer to the periphery of the stem

cork cambium

the cork cambium divides repeatedly to form \_____

cork

cork is the \_____ layer of bark, which acts as a protective plant layer

outermost

all plants undergo \_____ growth but only woody plants undergo \_____ growth

primary; secondary

what are the 3 categories of plant tissue?

ground; vascular; dermal

the \_____ tissue provides structural support to the plant

ground

the ground tissue makes up the most of a plant's \_____

mass

what are the 3 types of ground tissue?

parenchyma; collenchyma; sclerenchyma

\_____ has the thinnest cell walls of the 3 ground tissue types

parenchyma

parenchyma is a \_____ tissue, which provides the \_____ of the plant

filler; bulk

(parenchyma \= ground tissue type)

the \_____ ground tissue cells provide extra plant support, especially in areas where the plant is actively growing

collenchyma

collenchyma ground tissue have \_____ cell walls

irregular

sclerenchyma ground tissue is the main \_____ of the plant

structural support

have the thickest cell walls of the 3 ground tissue types

sclerenchyma

what are the 2 main components of the vascular tissue?

xylem and phloem

what are the functions of the vascular tissue?

transport material from the source to the sink

the \_____ is where plant nutrients are generated

source

the \_____ is where plant nutrients are used

sink

the \_____ transports sugars from the leaves (source) to the roots (sink)

phloem

(phloem is a sieve tube)

sugars are created in the \_____ via photosynthesis

leaves

what is the phloem made of?

sieve and companion cells

sieve cells are long cells with \_____ that allow substances to flow through them

pores

\_____ are connected together to form a sort of continuous tunnel

sieve cells

sieve cells lack \_____

organelles

\_____ cells are connected to sieve cells

companion

companion cells have the necessary \_____ to carry out metabolic functions

organelles

\_____ connect sieve and companion cells

plasmodesmata

the \_____ transports water from the roots (source) to the leaves (sink)

xylem

(notice roots are acting as a *source* of water in this case, while leaves are acting as a *sink* for water)

what are the 2 cells that make up xylem?

tracheids and vessel elements

\_____ are long, thin, and organized so that they are in contract with other \_____

tracheids; tracheids

water flows from tracheid to tracheid through \_____ found at their overlapping, tapered ends

pits

\_____ are shorter and stouter than tracheids, and they are in contact with other \_____ (for the most part)

vessel elements; vessel elements

water flows from vessel element to vessel element through \_____

perforations

in addition to water conduction, tracheids and vessel elements also provide..?

structural support

the \_____ is the central *region* of the root or stem, which is formed by vascular bundles of xylem and phloem

stele

the \_____ is tissue found at the *very center* of the root or stem

pith

the pith is made of \_____ ground tissue

parenchyma

what are the primary functions of the pith?

storeage and the transport of materials (like vascular tissues)

\_____ is the outer layer that protects the plant interior

dermal tissue

the \_____ tissue regulates how the plant is affected by its external environment

dermal

the \_____ is the type of dermal tissue that covers the outside of the plant

epidermis

the cuticle is a \_____ layer that covers the epidermis, and it '\_____' the plant

waxy; waterproofs

the \_____ is especially found in plants found in hot climates

cuticle

root hairs project out of the \_____ of root cells

epidermis

\_____ increase the surface area of the epidermis, which allows for greater water and nutrient uptake

root hairs

what are the 2 ways to move water between plant cells?

symplastic pathway; apoplastic pathway

how does water move in the apoplastic pathway?

water movement outside the cell, within the cell wall

how does water move in the symplastic pathway?

through the cell's cytoplasm

the \_____ regulates which substances can enter roots --\> travel to the rest of the plant

Casparian strip

what is the Casparian strip made of?

a fatty, waxy substance that makes it impenetrable

where is the Casparian strip found?

in the endodermal cell walls of plant roots

do plant cell walls have a way of filtering substances?

no

do the plasma membranes of root cells have a way of filtering substances?

yes, they are semipermeable membranes

stomata are found on the \_____ of leaves

lower epidermis

\_____ allow for gas exchange between the external environment and the plant

stomata

what are the specialized epidermal cells that surround stomata called?

guard cells

what do guard cells do?

control the opening and closing of stomata

how do guard cells open stomata?

K+ ions diffuse in, which causes water to follow by osmosis --\> the guard cell becomes turgid

during what period of the day is CO2 low in plants?

during the daytime, when photosynthesis is occurring

when are stomata open, and why?

stomata are *usually* open during the day to allow for the influx of more CO2 for photosynthesis

(stomata may close during the day to prevent transpiration, or if the plant is a CAM plant)

during what period of the day is CO2 high in plants?

photosynthesis does not occur at night time, so this is when CO2 builds up