DAT biological diversity pt 3 cheat sheet Flashcards
Simplest form of a plant with no specialized
vascular system
Thallophytes
Thallophytes are….
aquatuc
Aquatic and land habitats
bryophytes
Mosses, liverworts, hornworts
bryophytes
Dominant gametophyte stage
bryopjytes
Grow vertically and tall
Tracheophytes
Dominant sporophyte stage
Tracheophytes
ferns and pine trees
trachaeophytes
Undergo double fertilization
angiosperm
Most diverse land-based plant
angiosperm
Non-flagellated male gametes
angiosperm
Produce flowers and have pollen
angiosperms
Bear their seeds in fruits
angiosperms
One cotyledon
monocot
Parallel veins
monocot
Scattered vascular bundles
monocot
Fibrous root system
monocots
Flower parts in multiples of 3
monocots
Lilies and Kentucky bluegrass
monocots
Two cotyledons
dicot
Net-like veins
dicot
Ringed vascular bundles
dicot
Large single tap root
dicot
Flower parts in multiples of 4 or 5
dicot
Oak trees
dicots
Megasporocyte, the megaspore mother cells (2n), are converted into
four megaspores (n) via meiosis
Meiosis in Ovary (Female)
One megaspore (n) survives and undergoes
mitosis once fertilized to produce the egg cell and polar nuclei
Mitotic Divisions Produce Female Gametophyte
Help flank the cell and help attract/guide pollen tube to the female
gametophyte
Two Synergid Cells:
Microsporocytes (2n) à four microspores (n) via meiosis
Meiosis Within Anther
Microspore undergoes mitosis producing male
gametophyte (n), or the pollen grain. Male gametophyte (n) contains generative cell (forms into two
sperm) and tube cell (forms into pollen tube)
Mitotic Divisions Produce Male Gametophyte
Upon reaching ovule, two sperm are discharged
Pollen Tube Elongates Through the Style
One male gamete (n) fuses with the female egg gamete (n) to form an
embryo/zygote (2n) & another male gamete fuses with polar nuclei to form endosperm (3n)
Double Fertilization Occurs
final step of angiosperm lifecycle
Zygote Develops into Embryo
waxy protective
substance
cuticle
covering outside of plant parts
epidermal
help control gas exchange
guard cells
Responsible for most of the metabolic functions
ground tissue
Conducts
water and
minerals
throughout
plant
xylem
Provide
mechanical
support
xylem
Long and tapered,
water passes laterally from one to
another through pits
tracheids
Short and wide,
have little to no taper at ends,
perforations allow for H2O to pass
from one vessel element to
another
vessel elements
Transports
sugar
throughout
plant
phoelem
Made up of
cells called
sieve-tube
members
phoelem
Tough outer covering of seed that protects embryo/seed content
seed coat
(Seed producing plants only)
angiosperm
primary storage tissue (angiosperm)
endosperm
= transfers nutrients from endosperm to embryo (angiosperm)
Cotyledons
Angiosperm seeds are equivalent to
fertilized animal eggs
angiosperm embryo is diploid or haploid
diploid
Bending of a plant in response to light
phototropism
Bending of a plant in response to gravity
gravitropism
Growth response to mechanical stimuli
thigmotropism
Influences plant’s response to light +
gravity to stimulate growth/elongation
auxin
Promote flower + stem elongation
Gibberellins:
Stimulate cytokinesis (cell division)
cytokinins
Inhibits growth and promotes
seed dormancy
Abscisic Acid:
Promotes fruit ripening, flower
production, and leaf abscission
Ethylene Gas:
Protective layer covered w/ cuticle to reduce
transpiration (water loss through evaporation)
eipdermis
Has cells w/ chloroplasts and is the primary site
for leaf photosynthesis
palisade mesophyll
Consist of xylem and phloem – surrounded by
bundle sheath cell
vascular bundles
Specialized epidermal cells to control opening of
stomata and permit gas exchange
guard cells
Intracellular spaces allow for gas
travel
spongy mesophyll
Microscopic pore in epidermis that
allows for gas exchange between
plant and external environment
stomata
when stomata is open….
When open, CO2 can enter the leaf
where photosynthesis can then
occur to make sugar, can lead to water loss
Increases length of plant
primary growth
Increases girth of plant
secondary
A plant’s response to
changes in length of day
and night (photoperiod)
Photoperiodism
flower when sunlight is
less than half the day
short day plants
flower when sunlight is
more than half the day
long day plants