Plant cell biology Flashcards
Compare plants and animals regarding: how they get energy, mobility, cell components
Animals: hetertrophic, mobile, no cell wall
Plants: autotrophic with chloroplast, stationary, cell walls, central vacuole
What does the lack self-mobility mean about a plant and its environment? Are plants or are animals the better indicator of environmental conditions for life?
it means they have to become more well adapted to their environment than the animals in the same area. Therefore, The plants are more representative of the region and conditions for life
think about what the lack of a nervous system in plants means in terms of sensing environmental signals. Animal mobility and sensing requires it in many cases. Recall what I briefly said about plants sensing each other and sensing their environment
plants use mainly chemicals to communicate with each other, more rarely touch
What are the levels of plant structure from atoms to whole plant?
atoms, compounds, cell components, cells, tissues, organs, whole plant
What are the major elements important to a plant? What elements make up the 4 classes of biomolecules?
C, H, O, N, P, K, S, Fe Carbs: C, H, O Lipids: C, H, O, P Proteins: C, H, N, O, S Nucleic A: C, H, N, P, O
What are the two general classes of all plant cells?
living and dead
What is the name for the general living cell type of a plant?
Parenchyma cells
What are the two categories of parenchyma cells?
autotrophic, hetertrophic
What are the two major structures of a plant cell?
cell wall, protoplast
What are the major components or divisions of the protoplast?
Cell membrane, organelles, nucleus, cytosol (cell solution)
Which term would be most specific in indicating that an enzyme was found in the solution of the cell, cytosol or cytoplasm?
cytosol
What cell wall do all plant cells have?
primary
Is the primary cell wall somewhat flexible and can stretch or is it very hard?
somewhat flexible and can stretch
Describe levels of structure for fibrils found. Why are fibrils important?
glucose-> cellulose -> woven into microfibrils -> woven into firbrils
fibrils make up the primary cell wall
What other types of components are present in the cell wall, and what are some of their general uses in the wall?
cellulose, carbs, proteins, enzymes like cellulose synthase, rosettes that are part of cellulose synthase that spit out cellulose
What is the enzyme that synthesizes cellulose? What subunit is it made of that spits out the cellulose?
cellulose synthase
rosettes
What is the substrate for cellulose synthase?
UDP-uracine diphosphate
What enzyme supplies the UDP-glucose to the synthesis of cellulose?
sucrose synthase
Where is the secondary cell wall found?
b/w membrane and primary wall
Cells with thick secondary walls are used primarily for what function?
structure and support, is made of mainly dead cells
What is the substance that is found in most secondary walls that is not found in the primary wall and that gives strength to the secondary wall?
lignin
The outer boundary of the protoplast is formed by the __________.
cell membrane
What are the two major component materials of all membranes?
phospholipids, protein
Keep in mind that, unlike the cell wall, cell membranes are selective as to what passes through them. What component type provides that selectivity?
proteins?
What organelle takes up 80-90% of cell volume? What else does it do?
central vacuole
It is also used for water regulation and storage of toxic stuff
The chloroplast is a special version of what type of organelle? What is the major function of the chloroplast?What environmental signal stimulates the changes that result in a chloroplast developed from the generic form of the organelle?
plastid
to do photosynthesis
red light?
What major process occurs in the mitochondrion?
cellular respiration
The chloroplast and mitochondrion were once freely-living __________ cells.
What is the strong evidence for this unusual origin?
prokaryotic
their own DNA
What is the definition of a tissue?
group of cells that function in a similar or coordinated manner
What are the 4 major classes of tissue?
meristem, ground tissue, dermal tissue, vascular tissue
What basic process occurs in meristems?
cell replication via mitosis
Generally, where do apical meristems occur?
roots
Where do the lateral meristems develop? What does their activity result in?
near the outside of stem and root
increase in stem and root diameter
What do ground tissue do? (4)
fill space, storage, photosynthetic*****, support
What do dermal tissues protect from?
dehydration, uv, pathogens, herbivores
What do vascular tissues do?
conduct water, inorganic nutrients, and sugars to rest of plant
What is the difference between primary and secondary tissues?
primary tissues come from apical meristem
secondary tissues come from lateral meristems
How does the root grow longer? In other words, what are the two processes that are required for the root to grow?
Cell replication at the apical meristem and cell elongation by the older cells further up the root
What happens to cells once they reach their final size? What is an example of this in a fiber cell?
they mature to their final functional structure
Cells destined to be fiber cells develop secondary walls and die to become a fiber cells
What are the tissues of the cross section of a young, mature root? These tissues form from cells produced by the _______ meristem making them _______ tissues.
epidermis, cortex (made of ground tissue and parenchyma tissue), and vascular tissue (xylem, phloem)
apical; primary
How would I tell the xylem and phloem apart in the roots and stems of a dicot plant?
the xylem (tracheid, vessel cells, fiber cells) are much larger than the phloem
What cell type is a clear indicator of the xylem portion of the root of a flowering plant?
tracheid, vessel cells, and fiber cells because they all have lignin in 2ndary wall that can be stained red
What is the basic function of the endodermis? What feature of the endodermis allows it to perform its function?
separate vascular tissue from nonvascular; prevent apoplastic movement of water and nutrients from parenchyma to vascular tissue
??? Casparian Strip?(wax; like a brick and mortar)
What is the consequence of the endodermis?
it prevents movent of water and inorganic nutrients so the epidermis and cortex parenchyma tissue are the two tissues of the root that are responsible for water and inorganic nutrient absorption.
What is the result of lateral (branch) roots being formed from the interior of its parent root?
the lateral root will have primary tissue because it is being formed from a new apical meristem
Why do many biennials, such as carrot, store “food” in their roots?
carb reserves for future growth
What is the function of prop roots of tall grasses or most species in the fig (Ficus) genus?
It is a modified root coming from the stem that will grow down to help stay upright
What does adventitious mean?
organs arising from other organs
Propagative roots produce shoots. What tree types are well-known for producing shoots from their roots?
Aspen
The large group of genetically identical plants that were asexually produced by sprouting from roots is called a _____.
clone
What is the major function of a stem/shoot system?
to display or support the leaves
What do node, internode, lateral bud, and lateral branch mean?
node=place where leaf attaches
internode=section b/w 2 nodes
lateral bud=a meristem @ the node/leaf junction
lateral branch=what grows from lateral bud
. What is the general purpose of the various leaf arrangements on a stem?
to maximize light absorption
Which leaf arrangements have one, two, or more than two leaves/node?
1= alternate
2=opposite
>2=whorled
Where is the general region where the apical meristem is located on the stem? Name?
tip top part that is covered in tiny leaves
shoot apex
Generally, where do the immature leaves and lateral buds arise?
apical meristem @ shoot apex
Note that the region below the apical meristem region is the region of cell ________.
elongation
What is the type of ground tissue found in the primary stem?
cortex made of parenchyma tissue
How is the vascular tissue (xylem and phloem) organized in the typical dicot and monocot stem? How would the vascular tissues appear in a longitudinal view?
dicot= single circle of vascular bundle strands
monocot= vascular bundle strands spread throughout.
For both, the Xylem is pointed towards the inner part of the stem and phloem to the outer
What part of a primary stem could be used to make rope or cloth once the stem is dried?
a. Why is this portion of the stem useful for such commercial purposes? In other words, what are the cell types that make these uses possible?
vascular bundle strands
fiber cells
A corm is an underground stem that stores ___________ to support rapid growth of the above-ground shoot system in the spring. These are perineal unlike carrots
carbs
Example: crocus
What is the primary function of the white potato? The technical term for this structure is _________. What are the eyes of a white potato? Into what may they grow?
an asexual reproductive structure, a modified stem
tuber
shoots that may grow into roots
Rhizomes are horizontal underground stems for what purpose?
What is a type of plant that produces rhizomes and uses them very effectively?
to store nutrients and if it gets cut, a new plant will form
Bermuda grass
What part of a shoot system grows into a thorn? Do roses have true thorns? If not, what do botanists call the structure that the rose plant uses to keep animals away? From what tissue does it develop?
modified branches
No
prickles
epidermis
What are two reasons for why the stem of a young tree (or even of some annual plants) grows larger in diameter as the tree grows larger? Given the two functions of the increase in a stem’s diameter, what tissue would perform both of those functions?
- support for the crown
- need for more water conduction
xylem- all that wood is
Which of the two vascular tissues is produced more when a stem gets larger in diameter?
xylem
There is a particular type of lateral meristem that allows stem diameter to get larger by producing a large amount of 2nd-ary vascular tissue. What is this meristem that allows for secondary growth?
vascular cambium
Initially, where in a young, primary dicot or conifer stem does the vascular cambium arise?
between the primary xylem and phloem
Which cambium produces the periderm that replaces the epidermis as it cracks?
cork cambium
Remember that most of the periderm is made of dead _____ cells with ___ in their walls
cork cells
lignin?
In what region of the primary stem does cork cambium initially arise?
parenchyma cortex
Bark is all of the material outside of the __________ of a plant undergoing secondary growth.
vascular cambium
What are the two tissues that make up bark, keeping in mind that the epidermis is gone?
phloem and periderm
What happens to phloem after a year?
made of praencyma cells, it will produce new sections of cork cambium as a new layer of phloem is made
What are the many functions of bark?
transport sugar soln
protect from water loss, insects, pathogens, blows, and insulates
What is the difference b/w heartwood and sapwood? What are their functions?
heartwood= made of dead parenchyma cells so it is only good for support. it releases toxins toxic to fungi and insects; more resistant to rot
Sapwood=made of xylem, conduction of water and inorganic nutrients, support
Which area of the stem would be more resistant to decay if cut into lumber, the heartwood or the sapwood? Why?
heartwood
it releases toxins toxic to fungi and insects; more resistant to rot
Which region of the wood has no living parenchyma cells?
heartwood
Recall that some fungi can attack the heartwood of living trees. These fungi are pathogens feeding on the heartwood. What is the ultimate result of such an invasion?
heart rot
What type of cell is the only conducting cell of the conifer xylem?
?
tracheids?
What runs from the center of the stem outward in conifer woods?
narrow bands of parenchyma cells
What cellular structure composes each band during each year of growth for conifers?
tracheids
Which part of the growth ring (light or dark) would be the stronger and why?
dark b/w more tracheids=more lignin
What is the substance that seals wounds and smells good in conifers? What are its other functions?
resin; those are its main functions. made of smelly good volatile compounds and has antifungal properties
What is resin called when it dries? What can be distilled from resin?
rosin
turpentine
A. Resin in ducts in conifer wood has volatile chemicals. These chemicals evaporate from resin that oozes from a wound, leaving rosin that seals the wound. These chemicals have anti-________ properties, as well.
Antifungal
What are the structures of angiosperm wood?
tracheids, parenchyma cells (ray parenchyma), fiber cells, and vessels (the primary conducting cell).
In the latter part of the growing season of an angiosperm tree, a thin or thick (depending on the species) band of cells is produced that produces a band. What kind of cell predominates in this band? What makes this type of cell strong? Which band is stonger?
Fiber cells
Lignin in their 2ndary wall
Dark or light (small cells)
Many species of Angiosperm trees produce vessels of the same size throughout the growing season with thick-walled cells among them and also forming a band at the end of the season. What are these thick-walled cells that are abundant in maple and make maple wood hard?
?
What is the major function of a leaf?
To do photosynthesis
What are the basic parts of a leaf? What do veins do?
Petiole, blade, veins
Vascular tissue, vascular bundle strands
What is the function of the stomata?
To exchange CO2
To let air in and out of leaf to fill air spaces
What are mesophyll cells? What would be another name for mesophyll tissue and mesophyll cells?
they are photosynthetic parenchyma tissue of the leave
spongy mesophyll?
Note the large amount of air space in the leaf. What is the purpose of this air space?
to get CO2 to the mesophyll cells
What is a usually negative, consequence of having this air space in the leaf?
loss of water
What is an example of a plant with spines? What is the function of spines?
cacti
protection from herbivores; they are modified leaves that are not photosynthetic
Insect Traps are used to get what from the insect bodies? These plants grow in ________-poor soils, often in wetlands. Examples?
nitrogen
nitrogen
Venus Fly Trap, Sundews, and Pitcher Plants.
What is the basic function of a flower?
sexual reproductive structure of angiosperms
Of the basic parts of the flower, which ones are asexual and which ones are sexual?
asexual: petals and sepals
sexual: stamen and carpel
Since flowers are just modified leaves, what is their leaf arrangement?
whorl
What part of a stamen produces pollen? In terms of sexual reproduction, what does pollen produce?
anther
2 sperm
What is a carpel? What portion of the carpel contains one or more ovules? What cells do ovules have?
female reproductive structure
ovary
egg cell
If there is a carpel or a set of fused carpels, what is this called?
a pistil
What is the function of the stigma?
to catch pollen
What are the three ways that pollen can be transferred from the anther of one flower to the stigma of another flower (pollination)?
wind, animals, water
Generally, why has flower evolution focused on pollen transfer?
because it is sexual reproduction and the sperm needs to get to the egg for fertilization
What are the general characteristics of flowers of wind-pollinated plants? Do they have petals? Why or why not?
- lots of pollen
- large, feather stigmas
- individuals of a species grow together
No, because you do not need to attract animals
What is a common family of species that all use wind pollination?
grasses, maize
What are mechanisms of attraction used by animal-pollinated plants? What is the function of directional devices on flowers? Recall that sepals may be involved. How are they often used to attract an animal’s attention?
petals, sepals, odor
to bring in animals (lines, color differences)
they look like petals
What rewards does a flower potentially offer an animal?
nectar (a sugar solution)
pollen can be used as food
To which class of tissue does parenchyma tissue belong?
ground tissue
What is the important function of parenchyma tissue in leaves? What is a substance that might often be stored in parenchyma tissue?
they are photosynthetic in leaves
starches and H2O
What are plasmodesmata?
protoplasmic strands that connect parenchyma cells
The spaces between cell walls and the spaces within the walls belong to the region of an organ or tissue called the ________. Where does the symplast of parenchyma cells/tissue occur?
apoplast
inside the cell membrane
Sclerenchyma is a primary tissue composed of either fiber cells OR sclereid cells. What is the function of this ground tissue?
support ground tissue
What are the features of the fiber cell that allows it to perform the main function of sclerenchyma?
primary and secondary cell walls with lignin
What kind of cell comprises the epidermis? Is it a primary or a secondary tissue?
parenchyma cells
primary
What are the specific functions of the epidermis? What portion of the epidermis actually performs these functions?
to prevent dessication
cuticle-wax layer
What is the major reason for having the stomata in the epidermis? In other words, what is the main function of stomata?
to get CO2 into photosynthetic cells
When water moves into the guard cells, the stoma is _____________. When water leaves the guard cells, the stoma is ______________.
open
closed
What is the big paradox that plants face and that involves the epidermis?
should they open or close stomata. They need CO2 but lose water
What is the periderm?
A secondary covering for stem and root when the epidermis of a young stem/root is damaged by some process, as when the root/stem gets larger in diameter. Wounding resulting in damage to the epidermis also induces periderm production.
What is the major, important cell type of the periderm, and what is the material in the walls of these cells that is required for the tissue’s function?
cork cells
wax
What are the two basic functions of xylem?
support and conduction of water and inorganic nutrients
What was the first type of conducting cell? Describe its structure. Is it living or dead when functioning?
tracheid
long, slender, w/ thick secondary wall
dead
What features of the tracheid make it a good support cell? What features of the tracheid make it a poor conducting cell?
a thick secondary wall
resistance to water flow b/w its narrow and water can only get from cell to cell via fine holes
What is the cell type primarily used for conduction in the xylem of flowering plants? Support? Describe them
vessel cell-short and wide with large holes
fiber cell- 2ndary wall, long and slender
What is the main function of the phloem? What are the basic features of the phloem conducting cell compared to the features of the xylem conducting cells?
transport of sugar solution
conducting cells are mainly living cells
What modification is required as the phloem conducting cell matures to allow the flow of the solution through the conducting cells?
have lost their vacuoles to be better conductors
What are the 2 major functions of the root system?
anchor
absorb H2O and inorganic nutrients
Know the advantage(s) for tap roots and fibrous.
taproots- good anochoring system and allow for obtaining deep water
fibrous roots- absorptions of water and nuturients
What is the root cap and what are its two functions?
tip of root
- protect apical meristem
- gravity perceiving portion of the root
What are the two processes that result in an increase in the length of the root? Where in the root do these processes occur?
cell replication-apical meristem
cell elongation-cells further up root
What is the mechanism that members of the Aster family use to get many flowers pollinated by one visit of an insect?
they have clusters of flowers that look like one flower (sunflowers, black eyed susans)
Flowers that tend to be pollinated by birds have what general features?
they are red or yellow, also flower is long so that only beaks can get in there
Do bees normally pollinate red flowers?
no they are colorblind
How does a carrion flower trick an insect into transferring pollen?What type of insect usually pollinates carrion flowers.
they smell like rotten meat to make it seem like they have a reward, but they do not.
flies
Do all Angiosperms that are aquatic produce flowers? What is the approach that most aquatic angiosperm plants use to get successful pollination
No
they are either a sexual, their flowers bloom above water (example is the yellow-flowered bladderwort)?, or the flower’s pollen float on the water
From what flower part(s) does the fruit basically arise? What mechanism controls fruit development/growth?
carpel/pistil/ a swollen ovary
seed directs fruit growth via pheromones
What is the major function of fruits? What is the basic mechanism of fleshy fruits to get seed dispersal? What must the seeds have in order to do this?
spread the seed and prevent dessication
they are meant to get eaten and pooped out.
hard seed coat
What type of seed is an acorn? In the case of an acorn, a one-seeded fruit, if it is destroyed when an animal eats it, how does it help to get seed dispersal?
dry fruit that does not open
stored and forgotten
The cocklebur and the sand bur plants get the seed inside of their fruits moved by what mechanism? What type of seeds are they?
cling to fur
dry fruits that do not open
What type of fruits are dandelion seeds and seed of elms? How do they get dispersed?
dry fruits that do not open
wind
What are examples of dry fruits that open? What do they have in common?
willows, cotton
fluff and seeds blow in winds
All Angiosperm seeds start developing by storing “food” for the new seedling (embryo) in a special tissue called the _______. For many dicot species, this tissue continues to store at least some food, but some is also stored in the ______ of the embryo.
Endosperm
Cotyledon
For other dicot species, this tissue disappears, so all of the food is stored in the _____ of the embryo. What is a common example of such a seed?
Cotyledon
Peanut
For what purpose is food stored in the seeds?
To have nutrients available in order to germinate
What are the basic types of compounds stored in seeds? What is the most abundant stored “food” in grass seeds? It would be the major constituent of flour.
Carbs, oils, proteins
Starches
What is germination? What organ emerges first from the seed during germination
Emergence of plant from seed
Roots, to anchor
What happens to the complex compounds stored in the seed during germination? You need to be as specific as I was in lecture.
Carbs oils and proteins are digested to glucose, sucrose, and amino acids respectively
What are the three environmental factors required for germination
Water, oxygen, and certain temps. A cold season may be necessary
When is a seed dormant?
If given the three factors and the seed does not germinate, but is alive, the seed is dormant
