AP Botany

AP Bio (ECE)

Root system

Root system

All of a plant's roots, which anchor it in the soil, absorb and transport minerals and water, and store food.

Shoot System

The aerial portion of a plant body, consisting of stems, leaves, and (in angiosperms) flowers.

Root

An organ in vascular plants that anchors the plant and enables it to absorb water and minerals from the soil and stores carbohydrates

Taproot

A main vertical root that develops from an embryonic root and gives rise to lateral (branch) roots.

Fibrous root system

A root system common to monocots consisting of a mat of thin roots spreading out below the soil surface.

adventitious

a plant organ that grows in an unusual location such as roots coming from stems or leaves

root hairs

tiny hair-like extensions that increase the surface area of the root allowing it to absorbs more water and nutrients

mycorrhizal associations

symbiotic interactions with soil fungi that increase a plant's ability to absorb minerals

Stem

organ to which leaves are attached to and elongates and orients the shoot in a way that maximizes photosynthesis

Nodes

the points at which leaves are attached

internodes

the stem segments between nodes

Apical bud

composed of developing leaves and a compact series of nodes and internodes where growth of a young shoot is concentrated

Leaf

main photosynthetic organ but also exchanges gas with the atmosphere, dissipate heat and defend against herbivores and pathogens

petiole

The stalk of a leaf, which joins the leaf to a node of the stem.

Veins

the vascular tissue of leaves

Dermal tissue system

the plant's outer protective covering; forms the first line of defense against physical damage and pathogens

cuticle

A waxy covering on the surface of stems and leaves that acts as an adaptation to prevent desiccation in terrestrial plants.

Vascular tissue system

facilitates the transport of materials through the plant and provides mechanical support

Xylem

type of vascular tissue that conducts water and dissolved minerals upward from roots into the shoots

Phloem

vascular tissue that transports sugars, products of photosynthesis from where they are made to where they are needed

Stele

The vascular tissue of a stem or root.

ground tissue system

Plant tissues that are neither vascular nor dermal, fulfilling a variety of functions, such as storage, photosynthesis, and support.

Parenchyma cells

thin and flexible cell walls with a large central vacuole which perform most of the metabolic function and synthesize and store organic products

collenchyma cells

elongated cells with irregularly thick cell walls that provide support and structure to young parts of the plant shoot

sclerenchyma cells

rigid first and secondary cell walls that are specialized for support

lignin

a relatively indigestible strengthening polymer, present in all vascular plants but not in bryophytes

water-conducting cells of the xylem

-two types: tracheids and vessel elements, -dead, tubular elongated cells

sugar-conducting cells of the phloem

-Sieve-tube elements are alive at functional maturity, though they lack organelles

-Sieve plates are the porous end walls that allow fluid to flow between cells along the sieve tube

-Each sieve-tube element has a companion cell whose nucleus and ribosomes serve both cells

meristems

undifferentiated tissues that divide when conditions permit, leading to new cells that can elongate

Apical meristems

Embryonic plant tissue in the tips of roots and in the buds of shoots that supplies cells for the plant to grow in length.

primary growth

allows roots to extend throughout the soil and shoots to increase their exposure to light

secondary growth

Growth produced by lateral meristems, which thickens the roots and shoots of woody plants, causing them to grow in circumference

vascular cambium

adds layers of vascular tissue called secondary xylem (wood) and secondary phloem

cork cambium

replaces the epidermis with the thicker, tougher periderm

Cation exchange

H+ ions are actively pumped into the soil to displace positively charged mineral ions from the clay allowing the plants to uptake them

Stomata

pores found in the epidermis of leaves that allow exchange of carbon dioxide and oxygen between the surrounding air and photosynthetic cells

guard cells

two specialized epidermal cells found around the stomata that regulate the opening and closing of the stomata

mesophyll

ground tissue of leaf mainly composed of parenchyma cells specialized for photosynthesis

parasitic plants

absorb sugars and minerals from their living host plant

carnivores plant

need to eat insects in order to get nitrogen

Epiphytes

Photosynthetic plants that grow on other plants but don't harm them; get their nutrients from the rain

Bryophytes

gametophyte dominant; sporphyte is parasetic

Pteridophyta

free living gametophyte and sporophyte

Gymnosperm

dominant sporophyte with a dependent gametophyte

Angiosperms

dominant sporophyte with a dependent gametophyte

flowers

Reproductive structure of angiosperm sporophytes

Carpal

reproductive organ that has an ovary at its base and a long slender neck called the style

Stigma

sticky structure found at the top of the style that captures pollen.

Stamen

the male reproductive part of a flower consisting of the anther and filament where pollen is produced

embryo sac

The female gametophyte of angiosperms, formed from the growth and division of the megaspore in the ovary and comprised of 6 cells.

pollen grain

male gametophyte that develops in the anther of the stamen and is composed of 2 cells: generative cell and cell tube

Pollination

in angiosperms, it is the transfer of pollen from an anther to a stigma

endosperm

In angiosperms, a nutrient-rich tissue formed by the union of a sperm with two polar nuclei during double fertilization. Provides nourishment to the developing embryo in angiosperm seeds.

seed coat

A tough outer covering of a seed, formed from the outer coat of an ovule.

hypocotyl

Part of the developing embryo that will become the lower part of the stem and roots

radicle

the part of a plant embryo that develops into the primary root

epicotyl

Part of the embryo in a seed that becomes the upper part of the stem and leaves

fruit

A mature ovary of a flower that protects dormant seeds and aids in their dispersal.

simple fruit

A fruit derived from a single carpel or several fused carpels.

aggregate fruit

A fruit such as a blackberry that develops from a single flower that has several carpels.

multiple fruit

A fruit derived from an inflorescence, a group of flowers tightly clustered together, which fuse together as the walls of the ovaries start to thicken to become one fruit; a pineapple

self-incompatibility

The ability of a seed plant to reject its own pollen and sometimes the pollen of closely related individuals.

totipotent

any cell that can divide and asexually generate a clone of the original organism

tropism

A growth response that results in the curvature of whole plant organs toward or away from stimuli

Phototropism

growth of plant organ towards or away from light

auxin

Indoleacetic acid (IAA), a natural plant hormone that has a variety of effects, including cell elongation, root formation, secondary growth, and fruit growth.

Cytokinins

hormone that stimulates cell division, influence the pathway of differentiation, and control apical dominance

Gibberellins

A class of related plant hormones that stimulate growth in the stem and leaves, trigger the germination of seeds and breaking of bud dormancy, and stimulate fruit development.