Plants I Flashcards
Plants colonized land over 400 million years ago. Which group of algae is believed to be
the ancestor of land plants?
Charophytes
What are two adaptations that facilitate life on land?
alternation of generations - multicellular forms
walled spores produced in sporangia (multicellular organs) - sporopollenin makes spores resistant to harsh environments
Read carefully to find the five key traits plants share with green algae. List them here.
- chloroplasts with chlorophyll a and b
- distinctive rings of proteins - cellulose
- flagellated sperm
- nuclear, chloroplast, mitochondrial DNA
- Zygnema is closest living relative of plants
Some plants share production of sporopollenin with the charophytes, a lineage of green algae.
What is sporopollenin, and why is it important for life on land?
polymer cover that prevents them from drying out
Sexual life cycles always feature two key events. What are they?
meiosis - two sports develop into haploids (gametophyte)
fertilization is two haploids = one diploid (zygote) or (sporophyte)
If the gametophyte has 16 chromosomes, how many chromosomes are in the sporophyte?
32
In animals, the direct result of meiosis is a gamete. In plants, what is directly produced
by meiosis?
multicellular haploid gametophyte
Alternation of generations is a feature of the plant clade. Name the two generations that
alternate
gametophyte and sporophyte
Which plant generation is haploid and which is diploid
gametophyte - haploid
diploid - sporophyte
What is produced by the gametophyte generation?
haploid gametes
What is produced by the sporophyte generation?
unicellular haploid spores
What are sporangia?
multicellular organs that produce sperm
What are spores? How are they an adaptation to life on land?
haploid reproductive cells
What is the cuticle?
waxy covering on epidermis
What are the apical meristems?
enable root and stems elongate - help acquire resources
What are stomata
specialized spores to help gas exchange
What is vascular tissue?
cell tubes that transport water and nutrients
What is a seed?
embryo packed with nutrients with protective coat
What are gymnosperms? give example
naked seed plants, conifers
What are angiosperms? give example
flowering plants, trees
What are three types of nonvascular plants?
liverworts, hornworts, mosses
Vascular plants are divided into what two group? And they what comes from them?
seedless vascular - lycophytes (club moss) and pterophytes (ferns)
seed - gymnosperms (naked) and angiosperms (flowering)
What is a clade?
group of species including ancestors and descendants
Do the three groups of nonvascular plants form a clade?
no, bryophytes don’t form monophyletic group
Which two groups of nonvascular plants are most closely related?
mosses and hornworts
Are ferns more closely related to club moss or seed plants?
ferns and seed plants
Do seed plants form a clade?
yes
What’s made in the antheridium? Archegonium?
antheridium - sperm
archegonium - egg
What is made by gametophyte generation?
haploid
What is made by the sporophyte generation?
unicellular haploid spores
Where does meiosis occur?
anther and ovary
In animals, the gametes are formed by meiosis. In plants, what cells are formed by meiosis?
multicellular haploid gametophytes
How are spores dispersed?
by sporangia into the air
How does sperm reach egg?
through moisture film in archegonium
Which generation is haploid in pic?
gametophyte
Which generation is diploid in pic?
sporophyte
How do mosses absorb water? How is it distributed?
osmosis
Which moss generation is dominant
gametophyte (haploid)
What feature of ferns allows them to live in moist environments
swimming sperm that relies on water
What are the two types of vascular tissue? What does each transport?
xylem - conducts water/minerals
phloem - living cells for sugar and amino acids
Ferns are vascular, why are nonvascular plants tiny?
lignified vascular tissue allows for stems
nonvascular lack this
How does Lignified give vascular plants a competitive edge?
tall plants outcompete smaller plants - sunlight and spore dispersal
What are the functions of roots?
absorb water and nutrients
Which generation is dominant in ferns?
List characteristics of all seed plants?
reduced