exam 3 Flashcards
What made it hard for plants to colonize land for the first 500 years?
lack of water and UV radiation
How many major groups of plants are there?
4
What are the 4 major groups of plants?
- Vascular vessel seeds
- Vascular naked seeds
- Non vascular seedless
- Vascular seedless
Green algae and land plants shared a common ancestor approximately __________
1 billion years ago
Who was the common ancestor between green algae and plants?
Marine green algae
Green algae split into what two major clades?
Chlorophytes and charophytes
Chlorophytes……
never made it to land
Charophytes…….
sister clade to all land plants
Plants are photosynthetic with a few exceptions which include……..
Dodder vine, venus fly trap, pitcher plant and mistle toe
Plants provide……
Oxygen, food, clothing, shelter, fuel, and medicines to humans
Plants have limited amounts of water, they adapted to prevent water loss via the production of a 1._________. However, this limits gas exchange, which affects photosynthesis and cellular respiration. Thus plants adapted by using tiny mouth shaped pores called 2._______.
- waxy cuticle
2. stomata
stomata allows for…..
gas exchange and water to diffuse at the same time
What are the tracheids?
cells that are specialized to facilitate the transport of water and minerals
xylems carry______
water
phloems carry____
food
With the adaptation of the tracheids (xylem and phloem) plants where able to_______
increase their size, allowing for tees to grow more than 100 ft
Sporophyte
spore plant: the asexual and diploid phase in the life cycle
Gametophyte
gamete plant: the sexual and haploid phase in the life cycle
What are spores?
the first cells of the gametophyte generaion
The 1.______ generation can get very large, but the size of the 2._____ is limited in all plants
- sporophyte
2. gametophyte
what is a gametangia?
structures responsible for producing gametes
Bryophytes are called…… because they
Nontracheophytes because they lack tracheids
Bryophytes are the….
closest living descendants of the first land plants
How many species of Bryophytes are there?
16,000
What are the three clades of Bryophytes?
Mosses, liverworts, and hornworts
Bryophytes require _____ to reproduce sexually
water
Which phylum do mosses belong to?
phylum Bryophyta
Peat mosses (sphagnum) are important because__________
they absorb and hold water well
In mosses, gametophytes are 1.________. The eggs are produced by 2._______ in the 3._______
- haploid
- mitosis
- gametangia
the archegonia is the
female gametangia
the antheridia is the
male gametangia
Only one 1.______ is produced in an archegonium, but several 2._______ are produced in the antheidium
- egg
2. flagellated sperm
what phylum do liverworts belong to?
phylum Hepaticophyta
liverworts mean…..
plants or herbs
rhizoids….
fuction like roots and aid in absorption
who is the first known land plant?
cooksonia (had branches) and appeared 420 MYA
why were early tracheophytes successful land colonizers?
because they developed the water and food conducting system (vascular tissues)
the xylem goes…..
up
the phloem goes…..
down
it is the 1._______ that is the dominant generation in the tracheophytes
1.sporophyte
Roots would allow for larger plants for two reasons
- roots keep plants from falling over
2. extensive root systems are necessary to keep up with water demands
true leaves are called 1.______ and are found only in fern and seed plants, and have a distinct origin from that of 2.______
- euphylls
2. lycophylls
club mosses are in phylum______
phylum lycophyta
who was the first lycophyte to be sequenced?
selangnella moeliandorffii
how many gene families do green plants share?
3,814
how many genes did it take to transition from the unicellular alga to the multicellular moss?
3,000
how many genes were needed to transition from nonvascular to vascular?
516
antheridia contain…..
sperm
arhegonia contain….
eggs
phylum pterophyta contain 1.______,2.______,3.________
- whisk ferns
- horsetails
- ferns
what genus are horsetails in?
Equisetum
the hollow stems of of horse tails have ______ making them ideal for scrubbing pans and pots
silica deposits
what happened to the ferns that grew in rain forests over 300 MYA?
they are now the coal being mined in eastern US and Europe
how many species of seed plants dominate all terrestrial communities today and provide food, shelter, etc.
400,000
the embryo is protected by the 1._______. an extra layer or two of sporophyte which creates an 2.______
- integument
2. ovule
gynosperms lack _____ and _____
flowers and fruits
what does ‘‘gynosperm’’ mean?
gymno=naked/ sperma=seed
conifers belong to which phylum?
phylum coniferophyta
conifers make up ____% of the world’s forests?
40%
coastal redwoods (Sequoia sempevirens) are the….
tallest vascular plants (300 ft)
bristlecone pine (Pinus longaeva) are the……
oldest living trees (4900 yrs old)
vessels
efficient conducting cell type
Welwitschia are native to
southwest africa
most common genus in phylum gentophyta? (common to US and Mexico)
Ephedra
best known genus in phylum gentophyta? (vine that is cultivated as a vegetable)
gnetum
only ______ exists today to phylum ginkophyta
ginkgo biloba (maidenhair tree)
ginko are dioecious, what does this mean?
they have separate male and female trees
angiosperms include almost _______ known species
300,000
the carpel, a modified leaf, develops into the___
fruit
125 MYO angiosperm found in china
Archaefructus
most basic living angiosperm found in new caledonia in the south pacific
amborella trichopoda
classes of angiosperms
- archaefructus
- amborella
- waterlillies
- eudicots
- star anis
archaefructus
most primitive, now extinct
amborella
earliest known angiosperm that still exists
waterlillies
more primitive plant that are still aquatic
eudicots
largest group (175,000 species) they are annuals
star anis
known as a spice, it is also rather primitive
germination cannot take place until _____ and ______ reach the embryo
water and oxygen
seeds can remain viable for hundreds, and in some rare instances thousands of years as long as they dont…..
become wet/moist
some seeds will not open until they are exposed to____
fire
some seeds will germinate only when______ leach from their seed coats
inhibitory chemicals
some seeds will only germinate after they pass through___________
an animals digestive system
it is possible for fruits to grow without…..
seed development
dispersal methods
- vertebrates
- birds and mammals
- wind
- water dispersed
leaves, roots, branches, and flowers vary from….
plant to plant
Vascular plants consist of a ______ system and _____ system
root & shoot
apices (>1) or apex (1) are the
tips
roots and shoots grow at the
apices
root system (includes the roots)
anchors the plant and absorbs water
shoot system (includes the stems, leaves, and flowers)
positions the leaves for photosynthesis
who replaces the main shoot if something happens?
the axillary bud
axillary bud
lateral shoot appex that allows for branching. May produce flowers when the plant shifts to the reproductive phage of development
3 basic types of tissue
dermal, ground, vascular
dermal tissue
epidermis - outer protective layer that is one cell layer thick
ground tissue
inside of the plant (photosynthesis, etc.)
vascular tissue
conducts fluids throughout the plant
vascular tissue includes the …..
xylem and phloem
meristem cells
undifferentiated cells that can divide indefinitely and give rise to differentiated cells. Act as stem cells do in animals and are found in the shoot and root apices
apical meristems
found at tips of stems and roots. Where cell division and elongation of cells occurs
the root and shoot apical meristems need…..
protection
primary growth makes the plant…..
longer
secondary growth gives the plant…..
girth (thickness)
epidermis
covering of the plants
specialized cells in the epidermis
guard cells. trichomes, roothairs
guard cells
in charge of opening and closing the stomata
trichomes
reduce evaporation on leaf surface and as a defense against predation
root hairs
increase root’s surface area and absorption
in non flowering plants, ____ are the only water conducting cells
tracheids
transpiration
when water reaches the leaves and diffuses in the form of water vapor out of the leaves and into air via stomata
what happens if a plant is girdled (bark is removed)?
they die of starvation because the xylem is removed
4 root regions
root cap, zone of cell division, zone of elongation, zone of maturation
root cap
live less than a week. Form a mucilaginous lubricant that eases the root through the soil.
columellas cells contain_____ that collect on the sides of the cells facing the pull of gravity
amylopasts
zone of cell division
cuboidal cell division occurs every 12-36 hours
zone of elongation
cells become longer than wide
zone maturation
elongate cells become differentiated. Root hairs develop and can average 37,000 cm^2 and increase root surface area and absorption
most common roots
tap and fibrous
modified roots
prop, parasitic, food storage, water storage
prop roots
corn
parasitic roots
dodder plant (count dracula)
food storage roots
sweet potatoes, carrots, radishes
water storage roots
pumpkins
golden mean
137.5 degrees
the two parts of the stem include the______ and the ______
node and internode
node
region of leaf attachment
internode
stem area between two nodes
a leaf usually has a ____ and a _____
blade and petiole
an _________ is produced on each ______
axillary bud, axil
what are stipules
butterfly like appendages
rings in a tree stump reveal……
annual growth pattern
most stems grow…..
erect
modified stems
bulbs, rhizomes ,tendrils, cladophylls
bulb stems
(onions, lilies, and tulips) swollen underground stems
rhizome stems
(perennial grasses, ferns, and irises) horizontal stems that grow underground
tendril stems
(grapes and english ivy) modified stems that twine around supports ans aid in climbing
cladophylls
(cacti) photosynthetic stems that resemble leaves. in cacti, the leaves are the modified spines
leaves are vital because they are the principal sites for photosythesis on land
the base of the food chain
things crucial for the plants survival
leaf arrangement, form, size, and internal stucture
morphological leaf groups
microphyll and megaphyll
microphyll
leaf with 1 vein
megaphyll
leaf with many veins
modified leaves
floral, window, shade, insectivorous
floral leaves (bracts)
(poinsettias and dogwoods) surround the true flowers
window leaves
plants in arid regions grow cone shaped leaves with transparent tips for photosynthesis
shade leaves
grow larger and thinner than other leaves
insectivorous
(sundews,pitcher plant) produce cone shaped leaves that trap insects
true or false: plants go through developmental changes that lead to reproductive maturity just as animals do
true
plants must respond to______ and_____ signals that regulate flowering
internal and external
which factors determine when a flower is produced
light, temperature, and promotive and inhibitory internal signals
seeds arent dead they are
dormant
at germination plants…..
cant produce flowers
phase change
when plants can respond to signals to begin flower formation
reproductive stage can be very_____ or _______
subtle or morphologically obvious
true or false: even if a plant reaches the adult stage of development, it may not produce reproductive stuctures
true
4 genetically regulated pathways
light dependent, temperature dependent, gibberlin dependent,and autonomous pathway
day length changes with the seasons, the further a region is from the equator……
the greater the variation in day length
light dependent pathways
plants respond according to amount of light in a 24 hour photoperiod
short day plants
flower in winter (golden rod)
long day plants
flower in summer (irises)
day neutral plants
flower year round (tomatoes)
florigen
elusive flowering hormone we dont know if it exists
temperature dependent pathway
linked to cold
vernaliztion
period of chilling before plants are able to flower
which plants need vernalization
wheat, pecans, cherries
a complete flower has 4 whorls
clayx, corolla, androecium, and gynoecium
stamens
androecium
carpels
gynoecium
petals
corolla
sepals
calyx
true or false: calyx and corolla are not directly involve in gamete production or fertilization, but they enhance reproductive success
true
microgametophytes
pollen grains
megagametophytes
embryo sacs
angiosperm reproductive structures differ from those of animals in
- in plants both the male and female occur in the same flower
- in plants, the reproductive structures are not permanent
pollination
pollen is placed on the stigma
self fertilization
pollen from the same flowers anthers pollinates the same flowers stigma
cross fertilization
pollen from a flowers anther pollinates a different flower
pollinators
bees, butterflies, moths, birds, bats, wind
fertilization
complex, unusual process in which 2 sperm cells are used in a process called double fertilization
asexual reproduction includes
adventitious plantlets, runners, rhizomes, suckers, apomixis
adventitious plantlets
new plant individuals cloned from parts of adults (Kalanchoe aka. mother of a thousand)
runners
long slender stems that grow on the surface of the soil (strawberries)
rhizomes
underground horizontal stems (grasses and sedges)
suckers
sprouts which give rise to new plants (bananas, raspberries, and cherries)
apomixis
embryos in seeds produced asexually from the parent (kentucky bluegrass, dandelions)
annual plants
grow, flower, form fuits and die within 1 growing season ( sunflowers, corn, wheat, soybeans )
biennial plants
less common than annuals. Have life cycles that take 2 years to complete. Flower only 1 and then die ( carrots, cabbage,beets, queen annes lace)
perennial plants
grow year after year flower more than once (bamboo, oaks, pecans)
deciduous
leaves fall at a certain time of the year
evergreen
plant never completely bare
