BIOL 371 Topic 2 Plants

what level of cellularity is required to create specialized cells

multicellularity

t/f every cell in an organism has a slightly different genome

false; identical genome

t/f multicellularity results in tissue-specific activation of genes

true

t/f all land plants are prokaryotes

false; eukaryotes

t/f all land plants are photoautotrophs

false; almost all are photoautotrophs

are land plants multicellular or unicellular

multicellular

why are land plants sessile/stationary

they are photosynthetic and rooted into the ground so they don’t have to move to find food

t/f only some of land plants have cell walls

false; all have cell walls

land plants have an alternation of _______ life cycle

generations

in land plants, the _____ is retained on the gametophyte tissue

embryo

how can plants without chlorophyll be classified as plants and not fungi

they have flowers

what does the primary cell wall surround

plasma membrane and cell contents (cytoplasm + organelles)

in plant cells, bundles of cellulose are found in a matrix of ________

hemicellulose

t/f all plant cells have both a primary and secondary cell wall

false; all have primary but only some have secondary

t/f plant cells are rigid and inflexible

false; rigid because of turgor pressure but still flexible

the xylem and _______ are a part of the secondary cell wall

schlerenchyma

what are cellulose fibres anchored with in the secondary cell wall

lignin

how does lignin create a waterproof barrier

lignin is hydrophobic so it repels water

t/f the cell wall is what provides rigidity for the plant cell

false; turgor pressure makes it rigid

what organelle is responsible for creating turgor pressure

central vacuole

all the water lost or gained in plant cells is done through the process of ______

osmosis

what is meant by a “hypertonic” solution

hyper = more solutes in the solution than compared to in the cell

t/f water flows into the cell in a hypertonic solution

false; flows out towards the more concentrated solution

t/f isotonic solutions have net movement of water

false; no net movement

what is incipient hydrolysis

when plants start drooping because they are in isotonic solutions

what kind of solution should surround the plant cell for the cell to become turgid

hypotonic (water flows into more concentrated cell)

land plants alternate between a _____ gametophyte stage and ______ sporophyte stage

haploid; diploid

t/f the sporophyte produces diploid spores through mitosis

false; haploid spores created by meiosis

are spores unicellular or multicellular

unicellular

through what process do the spores germinate and become the gametophyte

mitosis

t/f the gametophyte is unicellular

false; multicellular

through what process does the gametophyte produce gametes

mitosis

the embryo is ___loid and ____cellular

diploid; multicellular

how many gametes can each gametophyte produce

1000

what 4 things constitute vascular bundles

• xylem

• phloem

• parenchyma cells

• fiber cells

what type of cell are fiber cells

sclerenchyma cells

what is the purpose of fiber cells in vascular bundles

provides rigid support to xylem and phloem

what would happen to the structure of a plant cell without sclerenchyma and xylem

phloem and parenchyma (sandwiched in between) are soft so the structure would not hold

what substance does the xylem transport

water

what substance does the phloem transport

sugar and solutes

what are water conducting cells strengthened by

lignin

t/f an advantage of having vasculature is that the plants can only stay on the ground but spread very far

false; vasculature allows for plants to stand tall and rigid

the presence of what 2 things are land plant classification based on

• vasculature

• seeds

what are the 3 main classification groups of land plants

• nonvascular

• vascular seedless

• vascular seed plants

which ploidy generation is dominant in nonvascular plants

haploid

which ploidy generation is dominant in vascular plants

diploid

t/f there is a direct fitness advantage between haploid and diploid generations

false; no fitness advantage but there is still advantages/disadvantages for both generations

why is it more advantageous to be diploid in the presence of deleterious mutations

the homologous chromosome has a functional copy that can be passed on (a longer diploid stage allows the accumulation of favorable mutations)

non vascular plants are known as _______

bryophytes

t/f bryophytes are tall plants with conducting tissues

false; no conducting tissues → stay close to the ground on wet sites (need moisture all the time)

what is meant by bryophytes being poikilohydric

they are unable to control/regulate their internal water content

what happens to poikhilohydric plants when their environment becomes dry

they dry out too

t/f bryophytes are drought avoiders, not tolerators

false; tolerators, not avoiders

what is the difference between drought tolerators and avoiders

• tolerators: have osmotic adjustments and cell wall elasticity

• avoiders: have stomatal conductance

what is the name of the female gametophyte in moss

archegonia

what is the name of the male gametophyte in moss

antheridium

t/f water is not needed for fertilization in the moss life cycle

false; water is essential

how do sperm cells end up in the archegonia in moss

rain droplets stick to the tip of the antheridium which releases sperm cells into the water → raindrops splash that water onto an archegonia

t/f moss sperm cells are flagellated

true

in moss the archegonia releases a sperm _____ which makes the sperm swim towards it and eventually into the opening

attractant

in moss the first sperm to swim down the archegonia enters the ____ ____ which ceates a diploid _____

egg cell; zygote

how are sporophyte moss formed

the 2 ends of the embryo in the archegonia expand in opposite directions, the upwards one grows vertically and makes the venter split in half → sporophyte

what happens to the end of the embryo that grows downward in moss

grows into the female stem so it can get water/nutrients from the female plant

what structure undergoes meiosis to produce spores

sporophyte/sporangia

what is a tetrad

cluster of 4 cells

how are new gametophytes created in moss

spores are released and land on the ground → germinates in the presence of moisture → forms a branched protonema → some protonema form buds → new leafy gametophyte

what structure anchors the gametophytes to the ground

rhizoids

t/f the protonema is filamentous

true

t/f rhizoids aid in water collection

false; only anchoring

t/f spores can germinate under any conditions

false; need water

what phase is dominant in bryophytes

gametophyte

what phase is dominant for seedless vascular plants

sporophyte

what are microphylls

narrow leaves with one strand of vein/vasculature

t/f microphylls are found in all seedless vascular plants

false; only in lycophytes

how are megaphylls different from microphylls

broader with multiple veins

_____ branching growth caused the development of megaphyll

unequal

what are fronds

finely divided leaves in pterophytes

t/f ferns need continuous moisture to survive

false; can survive w/o continuous

t/f in ferns, the spores that land first and germinate are asexual and are strictly male or female

false; bisexual and hermaphroditic

in ferns, the antheridium form at the _____ end of the ______

posterior; gametophyte

t/f fern gametophytes are no longer bisexual when they reach maturity

false; remain bisexual

what hormone is released when fern gametophytes are flooded with water

antheridiogen

antheridiogen _____ the growth of nearby plants and instead stimulates them to produce _______

stops; antheridium

what is the advantage of a bisexual gametophyte in a female phase releasing antheridiogen

surrounded by male gametophytes → increases chance of cross fertilization

t/f pterophytes do not have flagellated sperm

false

how are the flagellated sperm in pterophyte gametophytes released

ferns close to ground → easily flooded with water → water stimulates release of sperm

in bryophytes, water stimulates release of flagellated sperm and the opening of the ______

archegonia

in the presence of water the archegonia releases _____ ______ from the neck canal

sperm attractant

in pterophytes the fertilized egg remains attached to the _____

gametophyte

what does the foot of the fern embryo do

absorbs nutrients from the surrounding gametophyte tissues

what 2 structures form from the bottom of the fern embryo

• root

• rhizome (future stem)

the first fern leaf grows through the ____ in the gametophyte

notch

what are the 2 groups that make up vascular + seed plants

• gymnosperms (naked)

• angiosperms (flowering)

what is the dominant phase of vascular seed plants

sporophyte

pollen grains produce sperm that is not ____ in vascular seed plants

motile

t/f vascular seed plant fertilization requires water

false; not required unlike bryophytes and pterophytes

the ____ is a structure in the ovary that eventually becomes the seed when fertilized

ovule

t/f in gymnosperms the gametophyte structure produces female sporophyte with egg

false; sporophyte produces gametophyte w/ egg

in gymnosperms the zygote/embryo ______ and then disperses

dessicates

t/f spores, not pollen are released in gymnosperms

false; pollen is released