Gen Bio 1 Midterm 3

root system

anchors plant
absorbs water and ions

shoot system

support stems, leaves, and flowers
photosynthesis

dermal tissue

outer protective cover

ground tissue

squishy inside of plants
storage, photosynthesis, and secretion
forms fibers to support and protect plant

vascular tissue

conducts fluids and dissolved substances
xylem and phloem

meristem

plant version of stem cell
division produces another one and a differentiating cell

apical meristem

extension of shoot and root length

lateral meristem

increase in shoot and root diameter

root cap

protects root apical meristem

leaf primordia

protects shoot apical meristem

protoderm

apical meristem -> primary meristem
forms epidermis

procambium

apical meristem -> primary meristem
produces primary vascular tissue (xylem and phloem)

ground meristem

apical meristem -> primary meristem
differentiates into ground tissue

cork cambium

lateral meristem -> secondary tissues
produces outer bark

vascular cambium

lateral meristem -> secondary tissues
located under bark
produces secondary vascular tissues: secondary xylem and secondary phloem

guard cells

dermal cell
control the degree of openness of stomata

stomata

passage for oxygen, carbon dioxide, water vapor

trichomes

epidermal cells
shade stomata
some have glandular bulbs that secrete yucky stuff to deter herbivory

root hairs

dermal cells
increase root surface area for absorption of nutrients

parenchyma

ground tissue
function in storage, photosynthesis, and secretion of sap and stuff

chlorenchyma

parenchyma whose cells contain chloroplasts

collenchyma

ground tissue
provide support and protection
ex. strings you can pull off of celery

sclerenchyma

ground tissue
provide support and protection
ex. fibers

xylem

vascular tissue
conducts water and dissolved minerals
goes from root to shoot

phloem

vascular tissue
conducts food and nutrients (mainly sugar)
shoot to everywhere

columella cells

have amyloplasts which is an organelle with starch grains that collect and pull the cell down to gravity

root cap cells

outer part of root cap
continuously replenished by apical meristem

zone of cell division

center of root tip
site of apical meristem
cells divide producing daughter cells of apical meristem

zone of elongation

root lengthening
cells become longer than wide

zone of maturation

cells from elongation differentiate (dermal, ground, vascular)
root hairs are present

prop roots

modified roots
keep plant upright
ex. corn

aerial roots

modified roots
get water from the air
ex. orchid

pneumatophores

modified roots
facilitate oxygen uptake in swamps or wetlands by sticking up out of water
ex. mangroves

stems

carry leaves and flowers and supports the plant's weight

node

region of area of leaf attachment to stem

internode

portion of stem between 2 nodes

leaf

flattened blade and petiole (stalk of leaf)

axillary bud

produced at each axil (between petiole and stem)

terminal bud

extends the shoot during growing season
could turn into flower, fruit, or extension of shoot

monocot

vascular bundles scattered in stem
leaf forms parallel pattern

eudicot/dicot

vascular bundles in distinct ring
leaf veins form a net pattern

tubers

modified stems
swollen tip of stolon that contain carbohydrates
how plants store energy

tendrils

modified stems
twine around supports and aid in climbing

cladophylls

modified stems
flattened photosynthetic stems resembling leaves

leaves

principle site of photosynthesis

spines

modifies leaves
reduces water loss and may deter predators

angiosperms

flowering plants

phase change

plant is receptive to environmental signals (light, temperature, hormones) that signal that its time to flower, becomes flowering competent

photoperiodic

light dependent flowering pathway

vernalization

requirement of cold to induce flowering

gibberellin

stimulates stem elongation, germination, and flowering

flowers

house reproductive organs of plant
sperm in pollen
ovary and ovules

monecious

having male and female reproductive organs in the same plant

diecious

having male and female reproductive organs in separate plants

dichogamous

either only male or female structures on one plant that are not active at the same time

androecium

all male structures
stamen - anther, filaments

gynoecium

all female structures
carpel - stigma, ovary, ovule

alternation of generations

how flower gamete production occurs
diploid sporophyte makes haploid gametophyte

male gametophyte

pollen grains

female gametophyte

embryo sac

self-pollination

pollen from anther f a flower fertilizes the ovary of the same flower

cross-pollination

pollen from the anther of a flower fertilizes the ovary of a different flower

wind pollination

passive pollination
typical distance traveled is about 100 meters

endosperm

food for developing embryo

suspensor

connects the embryo to endosperm

cotyledons

embryonic leaves

hypocotyl

embryonic stem

seed coat

encloses seed with stored food
allows seen to survive harsh environments

germination

emergence of the first root (radical) through the seed coat

stratification

holding at low temperature for germination to occur

pericarp

ovary wall
forms fruit

exocarp

skin of fruit
outermost layer of pericarp

mesocarp

flesh of fruit
the middle layer of a pericarp

endocarp

pit of fruit
innermost layer of pericarp

perennial

plants that grow, reproduce/flower yearly

deciduous

all leaves fall at one time

evergreen

leaves drop throughout the year, never bare

annual

plants that grown, reproduce, and die in one year

biennial

plants that grow, reproduce, and die in 2 years

water potential

how freely available water is

turgid

central vacuole is full of water and pushing against cell wall
normal, happy plant

plasmolysis

cell is shrunken because cell membrane has pulled away from cell wall
sad, wilted plant

cohesion

water sticks to water

adhesion

water sticks to xylem

translocation

movement of carbs/sugars made in the leaves to the rest of the plant

phloem loading

sucrose enters the phloem at the source by active transport of sucrose across membrane

nodule

plant tissue that houses nitrogen fixing bacteria

nitrogen fixation

chemical process of converting N2 gas to organic compouds by microorganisms

mycorrhizae

plant roots and soil fungi form association
increase absorption surface area for absorption of nutrients

phytoremediation

use of plants to concentrate or break down pollutants from soil

Phytodegradation

contamination is taken up from soil and broken down

Phytovolatilization

contamination is taken up from soil and release something less toxic through stomata

Phytoaccumulation

contaminant is taken up from soil and concentrated in the shoots, plant holds on to junk

secondary metabolite

chemicals produced by plants via metabolic pathways that are not used for normal growth, development, or reproduction

ricin

found in castor bean endosperm
lethal

manihotoxin

from cassava
makes cyanide

phytoestrogen

from soybean
mimics estrogen

taxol

from yew
anticancer drug, inhibits microtubule degradation which inhibits cell division

quinine

from quinine bark
antimalarial drug

morphine

from poppy
narcotic pain killer