Studied by 49 people
T or F
the mitochondrion and chloroplast evolved only one time in the evolution of eukaryotes
T ( evolution is not related to secondary and tertiary endosymbiosis)
Algae
entirely aquatic plants, not monophyletic
advantages to living on land
more access to carbon dioxide, more sunlight
Challenges to life on land given the aquatic ancestry
desiccation
no support for body
reproduction
Glaucophytes
freshwater, unicellular algae that have a layer of peptidoglycan in their chloroplasts
(evidence that chloroplasts arose via primary endosymbiosis because chloroplasts were once bacteria)
Uses chlorophyll a (same as cyanobacteria)
Green Plants
uses chlorophyll a and b
increased photosynthetic capacity
ability to store starch
The four adaptations to life on land
sporophyte
waxy cuticles
protected embryos
sporopollenin
( all related to the land plant life cycle)
mitosis
no change in the copies of chromosomes per cell (2n→ 2n, n→ n)
meiosis
reduction of chromosomes per cell
(2n→ n)
Diplontic life cycle
diploid stage is dominant and multicellular (2n)
no multicellular haploid stage (n)
does not occur in plants
T or F
In eukaryotic life cycles, the embryo results from the meiotic division of the zygote
F, it is mitosis not meiosis
Do plants make gametes by meiosis or mitosis?
mitosis
What are zoospores
-the product of 2n zygote undergoing meiosis resulting in four swimming spores
Haplontic life cycle (most but not all algae)
Has a dominant and multicellular haploid adult but no multicellular diploid stage
Alternation of Generations
has both adult, dominant haploid and diploid stage ( gametopyte and sporophyte)
bryophytes
early- diverging land plants
non vascular
lack lignified vascular tissue (xylem and phloem)
no leaves or roots ( has rhizoids)
diffusion
low to the ground and small
T or F
Bryophytes are monophyletic
F
Poikilohydry
water content matches that of the environment
If bryophytes lack xylem and phloem, by what process does water enter cells?
diffusion
Bryophyte body plan
dominant gametophyte generation (main body)
smaller, nutritionally dependent sporophyte generation
Archegonia
structures that produce eggs
antheridia
structures that produce sperm (must swim to the archegonia)
sporopollenin
protein that coats the outside of spores to reduce water loss
Liverworts body plans
thallose
leafy
they have the smallest sporophytes in land plants
sporangium
container of spores (moss has them)
hornworts
has persistently green sporophyte with indeterminate growth
What is not evidence that supports the endosymbiotic origin of the chloroplast from cyanobacteria?
use of chlorophyll a by glaucophytes
multiple membranes around the chloroplasts
haploid chloroplast genome
peptidoglycan in the chloroplasts of bryophytes
circular chloroplast DNA
peptidoglycan in the chloroplasts of bryophytes
Do bryophytes or glaucophytes have peptidoglycan in the chloroplasts?
glaucophytes, they are the only lineage that have peptidoglycan- very good evidence of the endosymbiosis of the chloroplast
In homosporous alternation of generations:
one sporophyte produces one size of spore
Hornworts in contrast to other bryophytes have:
persistently green sporophytes
Plasmodesmata
cell to cell junction in plants ( strong evidence that multicellularity evolved independently )
What is in a primary cell wall?
cellulose and hemicellulose (no lignin)
What is in the secondary cell wall?
Cellulose, hemicellulose, and lignin
Meristems
regions of undifferentiated cells, can develop into any different types of plant tissue
What are the two types of meristem
apical and lateral
What are the two types of apical meristem
SAM and RAM
Dermal tissue
form the epidermis and secrete waxy compounds that protect the plant from desiccation
Vascular Tissue
(xylem and phloem) transport water, minerals and sugar
Ground tissue
fills in the inner space of the plant and performs metabolic and storage functions.
purpose of lignin
Bryophytes do not have lignin, plants that need to grow tall have it.
What are the 3 types of ground tissues
parenchyma, collenchyma, sclerenchyma
Parenchyma
does most of the work
photosynthesis happens
sugar is stored
alive
Collenchyma
Celery
bendy
alive
support
Sclerenchyma
dead, woody tissue (attached to lignin)
toughest
What are the four organs?
Leaves, Stems, Roots, Flowers
Parts of the leaves
Blade, Midrib, petiole
stomata
where gas exchange occurs for photosynthesis
guard cells ( for stomata)
like lips, closes if it gets too dry
Difference between leaves and stems
Stems have meristem and leaves do not.
They also have nodes
What are nodes and internodes?
nodes: collections of meristematic tissue from which leaves or other organs grow
internodes are the sections of stems between nodes
How to tell the difference between leaves and stems
the presence of nodes
What are the parts of roots
root apical meristem
root cap
root hair
What do root hairs do?
they increase surface area for water and mineral absorption
What do root caps do?
protects the RAM, secretes lubricant for easier growth
Tracheids
first type of xylem tissue that evolved
all vascular plants have tracheids
What are the innovations of vascular plants
tracheids, roots, bigger sporophytes
Are bryophytes gametophyte or sporophyte dominant?
gametophyte
Are vascular plants gametophyte or sporophyte dominant?
sporophyte
Advantages of larger sporophytes
They have wider range to disperse spores as well as more production
What are the two types of vascular tissue
xylem (water) and phloem (sugar)
Two types of xylem
trachieds (all vascular plants)
vessel elements (some vascular plants)
(dead)
Phloem parts
sieve tube- flow of sugar (no organelles)
companion cells- regulates sieve tube
(alive)
