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