unit9 (plant bio)

vascular plant

xylem and phloem, tall, variety of environments, angiosperms + gymnosperms

non-vascular plant

no xylem, no phloem, small close to water sources, moss

gymnosperms

conifers, seeds and cones

angiosperms

flowering, monocots, dicots

conifer

cones and seeds, needle leaves,

meristems

unspecialized cells, plant stem cells

apical meristem

tips of roots and stems, primary growth, lengthening

lateral meristem

secondary growth, diameter and thickness

auxin

hormone that promotes positive phototropism, growth of roots, cell elongation towards light, in apical meristems

tropism

growth or movements from an external stimulus

phototropism

growth or movement towards external light source

gravitropism

growth in response to gravity, opposite of phototropism

micropropagation

in vitro process that produces large number of cloned identical plants, preserve endangered plants, production of desirable characteristics

photoperiodism

response to length of light, causes flowering

long day plant

short night, "hard worker", summer plants

short day plant

long night, "lazy", winter plants

anther

holds pollen, produces male sex cells

filament

supports anther

ovary

develops female sex cells

ovule

contain the egg

petal

attract pollinators

sepal

protects developing flower bud, look like leaves

stigma

sticky landing spot for pollen

style

supports stigma

pollination

transfer of pollen grains to stigma

germination

pollen tubes grow from pollen grain

fertilization

sperm travel down the style to egg cells

root meristems

growth and extension of root

shoot meristems

shoot growth, development of flowers and leaves

monocot

one cotyledon, fibrous roots, multiples of three, parallel veins on leaves, scattered vascular bundles

fibrous roots

no main root, several main roots that each branch off to form a mass of roots

dicot

two cotyledons, tap roots, 4 or 5 petals, branched veins on leaves, ringed vascular bundles

tap root

on main root with others growing off of

vascular bundles

structure that contains xylem and phloem

deciduous tree

sheds its leaves and grows new ones each year, loses leaves, maple and oak tree

evergreen tree

keeps leaves through winter, pine tree

hormone

chemical messages made in one part of plant that have an effect in another location

indole 3 acetic acid, IAA

type of auxin, controls growth at shoot apex, promotes cell elongations

PIN3 proteins, pin3

membrane proteins that move auxin across membranes.

vegetative structures

roots, stems, leaves

phytochrome

pigment or photoreceptor used to detect light

Pr

inactive phytochrome, 660nm

Pfr

active phytochrome, 720nm

stamen

male reproductive organ

carpel

female reproductive organ

receptacle

base of flower

wind and water pollinated plants

small, dull colour, no smell, small petal, smooth grains, grass

animal pollinated plants

larger, smell, bright colour, larger petals, rough grains, tulip

self-pollination

pollen from anther falls onto own stigma, less genetic variation

cross-pollination

pollen carried to another plant of same species, genetic variation, could leave stigma without pollen

seed production

egg divides and forms zygote

seed dispersal

seeds moved away from parent plant, through water, wind or animals

xylem

vascular tissue that moves water up the plant

phloem

vascular tissue that moves sugars and amino acids through plant

cuticle

waxy layer that prevents water loss

epidermis

outer layer that provides protection

palisade mesophyll

where photosynthesis takes place

spongy mesophyll

gas exchanges happen

stomata

openings that release water and oxygen

guard cells

controls opening and closing of the stomata

evaporation

liquid going to the atmosphere

transpiration

water evaporates through leaves, stems and flowers

transpirational pull

roots pull water up xylem through the forces of cohesion and adhesion and evaporates out the leaves through the stomata

cohesion

water molecules sticking together

adhesion

water molecules attracted to other polar molecules or surfaces

nutrient sources

where sugars are produced, leaves/stems

nutrient sinks

where sugars are used or stored, roots/buds/stem/seed/fruit

translocation

movement of sugars from sources to sinks

phloem loading

the active process of sugars moving from source to sink

xerophytes

plants adapted to dry conditions, cactus, deep roots/ specialized water storage/ open stomata at night, can have photosynthesis done in 2 cells

halophytes

plants adapted to salty conditions, conifer, small spines/scaley leaves, stem photosynthesis, leaves can store water, sunken stomata, long root hairs