Exam 2 Flashcards
Monokaryotic (n)
cell has one or more haploid nuclei of a single genetic type
Plasmogamy
sexual fusion of cytoplasm of two cells, and followed by karyogamy
Dikaryotic (n+n) “heterokaryotic”
a cell containing genetically different nuclei
Karyogamy
fusion of two nuclei
Hyphae
filaments comprising the body of fungus. chains of connected cells
sexual reproduction of fungi cycle (8)
- meiosis 2. haploid 3. gametes. 4. haploid and monokaryotic 5. plasmogamy 6. haploid and dikaryotic 7. Zygote Karyogamy 8. Diploid
Sexual reproduction may
involve union of (4):
- hyphae
- motile gametes
- male and female gametangia
- female gametangium with motile or non-motile sperm
yeast
single globular cell body type, morphological not taxonomical
mycelium
mass of many hyphae, clustered in one fungal body, located underground
coenocytic
the multinucleate hyphae without cell walls in mycelium
budding
(yeast) mitotic cell division is the common way the fungus exploits a resource-rich environment
asexual spores (mitospores)
spores produced by mitosis
asexual reproduction of fungi cycle
- mycelium 2. mitosis 3. spores 4. germination
modes of asexual reproduction
fragmenation, budding, and asexual spores (mitospores)
two main body forms of fungi
mycelium and yeast
mycelium septate
cell walls separating each successfully arranged cell with a nucleus in mycelium
evolutionary origin of fungi
similarities to animals (3)
opisthokonta eukaryotic supergroup (posterior flagellum).
similarities of animals and fungi:
1. similar DNA sequence for ribosomal RNA involved in protein synthesis
2. motile cells have flagella
3. mannitol and trehalose are similar to storage compounds in animals
distinguishing features of fungi (7)
domain, mode of nutrition, cell walls, _loid nuclei, sexual or asexual spores?
1) Eukaryotic, membrane-bound organelles- ER, vacuoles, and mitochondria
2) Hyphae, apical growth, mycelium, yeast
3) Heterotrophs
4) Cell walls made of chitin and glucans
5) Storage compounds – mannitol, trehalose, glycogen
6) Haploid nuclei
7) Sexual and asexual spores
distinguishing features and evolutionary origins of chytridiomycota (6) cell walls?, single or multicellular?, found where, haploid or diploid, about spores, structure
earliest branch of fungi.
- have chitin and glucans in cell walls
- only true fungi that produce motile flagellated spores
- typically singe-celled
- found on decaying matter in moist soils or aquatic environments or rumen of animals
- anchored to their organic substrates with thin tapering rhizoids
- alternate between two generations: haploid and diploid
distinguishing features and evolutionary origins of zygomycota (5) haploid or diploid, about spores,
second branch of fungi.
- Ceonocyctic (hyphae without septa)
- Haploid only generation (monobiontic)
- Only group to produce large, resting zygospores after karyogamy
- sexual spores produced in large sporangia on stalk
- Rhizopus is the genus for bread mold
distinguishing features and evolutionary origins of glomeromycota (5)
third branch of fungi
- Form mycorrhizae with roots of plants, type of mycorrhizae called VAM
- use arbuscule for symbiotic exchange with plants.
- use vesicles to store lipids
- fossils from devonian period show widespread association between fungi and roots of early plants like in Asteroxylon and Rhynia
- asexual reproduction only
apical growth
they add and grow new cells on the terminal ends of the filaments the apex or the apices
heterotroph
they need pre-formed organic compounds as energy and also as carbon skeletons for biosynthesis of other compounds
chitin
part of cell wall, long chains of glucosamine a nitrogen containing molecule that is derived from glucose
glucan
part of the cell wall, branched polymers of the simple glucose molecule
mannitol
fungi store energy in this sugar alcohol
trehelose
fungi store energy in this disaccharide
rhizoids
long, tapering root-like absorptive. secrete enzymes that break down complex organic material into simpler forms to be absorbed by the fungus
zoospores
asexual vs sexual reproduction
asexual reproduction- with the release of motile zoospores after finding a suitable substrate the diploid asexual zoospores will form dormant cysts.
sexual reproduction- cells of the
diploid fungus body form sporangia and through meiosis form haploid zoospores
they are motile with a single flagellum and appear to be very similar to the flagellated cells of animals so we call them zoospores these
cysts
dormant spores.
asexual zoospores form dormant cysts. cysts germinate to produce another diploid phase body
sexual zoospores? cysts germinate to form a haploid generation spores released from the haploid phase are gametes
coenocytic
lacking partition walls in a filament or hyphen
zygosporangium
in Zygomycota, two different genetic mating types find each other and form gammatangia that then fuse into a zygosporangium
zygospore
in Zygomycota, haploid nuclei from the different mating types fuse or undergo karyogamy in the zygosporangium to form a large zygospore which often forms a large warty surface dormant spore
mycorrhizae
in Glomeromycota, close symbiotic relationships involving fungi and plant roots. mycorrhizae are associated with the vast majority of plants
vesicular arbuscular mycorrhizae (VAM)
the type of mycorrhizae formed by fungi of the glomeromycota
vesicle
in Glomeromycota, stores lipids (energy) for fungus
arbuscule
in Glomeromycota, highly branched hypha inside root cell of plant. symbiotic exchange nutrients with the plant and acquire sugars from the plant.
distinguishing features and evolutionary origins of ascomycota
fourth branch of fungi.
ascus!!!
life cycle stages and structures of ascomycota
- how are spores discharged?
- sexual vs asexual
- steps (4)
-spores are discharged from sporocarps passively and actively by wind, hydrostatic pressure and force of a raindrop hitting sporocarp
noted for producing large multicellular structures from coordinated assembly of their hyphae during the sexual phase of their life (sporocarp)
asexual spore production happens during haploid monokaryotic phase
haploid dikaryotic phase- two genetic mating types join their protoplast during plasmogamy
1. after plasmogomy, two haploid nuclei of compatible and different mating types come together fuse and karyogamy to form a diploid nucleus
2. the diploid nucleus undergoes meiosis to form haploid sexual spores
3. the meiotic division which forms four ascospores is followed by a mitotic division to produce eight ascospores, in brewers yeast, only form 4 spores
1. haploid dikaryotic in plasmogamy
2. karyogamy to diploid nucleus
3. meiosis to 4 haploid sexual spores
4. mitotic division 8 ascospores
examples of ascomycota
common brewers or baking yeast, ergot fungus- develops perithecium parasitic to cereal crops (ergot disease)- grows on flowers, black truffle- cleistothecium
life cycle stages and structures of basidioimycota
4
producing large multicellular structures from coordinated assembly of their hyphae during the sexual phase of their life (sporocarp)
haploid monokaryotic and haploid dikaryotic
mushroom is haploid and dikaryotic development of basidium, sterigma and basidiospores
a - after karyogamy (the zygote 2n nucleus)
b - after meiosis producing 4 haploid nuclei
c - development of the sterigma and protoplasts to receive the haploid nuclei
d – migration of the 4 haploid nuclei into the external basidiospores
ascocarp
– the ascospore-bearing, multicellular sporocarp of Ascomycota (mushrooms)
ascus
- the “sac” with ascospores Plural - asci
distinguishing feature of ascomycota
apothecium
a fertile region on an ascocarp where the ascii are not covered by sterile fungal tissue at maturity
the asci that contain the spores are open freely to the outside environment as they mature and release their spores
perithecium
a type of fertile region on an ascocarp. a closed structure on the ascocarp where the asci are surrounded and enclosed by sterile mycelial tissue
the sterile wall has a regular means of opening with a slit or pore
cleistothecium
a type of fertile structure, characterized by having sterile tissue that completely encloses the ascii inside but in this case there is no opening that allows the spores to be released to the outside
basidiocarp
a sporocarp produced by a member of the Basidiomycota and which bears basidiosores (mushrooms)
distinguishing features and evolutionary origins of basidiomycota
fifth branch of fungi. sister group with ascomycota- form mushrooms.
2nd largest phylum
1. BASIDIUM!!!
sporocarp
A multicellular body or structure that produces and contains spores. “sporo” = spore; “carp” = fruit… “spore-fruit”
basidiospore
basidium produces 4 haploid spores, produced on outside of spore bearing structure, held up by sterigma
Basidium
a cell in which karyogamy and meiosis take place and which bears external spores, the basidiospores, of sexual origin
sterigma
the spike-like structure on the basidium that supports the external basidiospore
clamp connection
growing haploid dikaryotic hyphae develops clamp connection
clamp branch forms and the two different nuclei when undergoing mitosis distribute themselves on each side of the clamp with one nucleus being returned backwards to ensure that each cell receives one of each type of nucleus as they are added
gilled fungi
basidia form on surface of gills underneath cap to develop basidiospores
fairy ring
sporocarps of gill fungi on occasion grow in large rings across the soil surface, defines the outer margin of the growing mycelium in the soil
inky cap fungi
type of gilled fungi- inky slime that helps to shed off outer parts of the cap that already have released their spores to the air allowing the basidia towards the center to have a greater chance of dispersal
polypore fungi
basidia develop inside the pores and release their spores down the tube that makes the pore polypore fungi include those that infect trees and produce shelf-like basidiocarps on the side of the tree
bracket fungi
type of polypore- some bracket fungi grow their mycelia into already damaged and dead parts of the tree trunks and live as saprotrophs but others are parasitic growing their hyphae and mycelium into the living tissue of the tree and become pathogenic and damaging to the tree
puffballs
at maturity release their spores through open slits or pores on the top after something agitates the structure
jelly fungi
no gills or pores. a durable gelatinous or jelly-like mass these structures can desiccate during dry periods and then reconstitute after wet periods and continue to produce new basidia and release spores from their surface the hyphae that make up the basidiocarp and the jelly fungi do not have rigid walls
rust disease
rust fungi damage cereal crops the little rust looking pustules on the surfaces of infected plants are asexual spore structures that spread the pathogen throughout the field during the main growing period
life cycle has wintering phase on secondary host
barberry- secondary host for wheat, campaign to eradicate this
examples of basidiomycota
gilled, inky cap, polypore, bracket, puffballs, jelly, rust fungi
protoplasm/ cytoplasm
everything inside the cell excluding the outer wall
cytosol
the fluid mass that surrounds and provides a home for the organelles
plasma membrane (3)
1) Regulate passage of molecules
2) Divide the cell into numerous specialized compartments
3) Act as surfaces that hold enzymes for metabolism
endoplasmic reticulum (smooth and rough)
– a system of narrow tubes and sheets of
membrane that form a network throughout the cytoplasm.
Rough ER – ribosomes attached, involved in protein synthesis
Smooth ER – no ribosomes attached, involved in lipid synthesis
central vacuole
membrane bound (tonoplast) space in plant cells which stores material, either dissolved in water or as a crystalline mass, 85% of cell volume
tonoplast
membrane surrounding central vacuole
cell wall (primary and secondary)
Primary cell wall – thin, cellulose microfibrils
and other polysaccharides (pectins, hemicelluloses)
Secondary cell wall – thick, includes cellulose microfibrils, other polysaccharides and also is cemented together with lignin
cellulose
A structural polysaccharide found in the cell walls of plants.
- polymers of glucose,
- arranged in bundles called microfibrils in cell walls
- a component of all primary and secondary cell walls
lignin
a complex branched polymer that impregnates
the cellulose microfibril network only in secondary cell walls
making the tissues stronger, water proof and more
resistant to attack by fungi, bacteria and animals
parenchyma
Thin primary walls. Typically alive at maturity. Many
functions. water storage cells
chlorenchyma
photosynthetic parenchyma cells (chlorophyll)
collenchyma
Unevenly thickened primary walls. Typically alive at
maturity. Provide plastic support. allows plant to bend
scelerenchyma
Primary and secondary walls. Often dead at maturity.
Provide elastic support and some are involved in water transport.
sclereids type of sclerenchyma cell
(mechanical) – isodiametric, often dead at maturity
fibers type of sclerenchyma cell
(mechanical) – long, mostly dead at maturity
tracheids type of sclerenchyma cell
(conducting) – long and narrow with tapered ends, dead at maturity, no perforations, all vascular plants, have lignin and secondary cell walls
vessel elements type of sclerenchyma cell
(conducting) – short and wide with perforations at ends, dead at maturity, found almost exclusively in flowering plants, have lignin and secondary cell walls
Meristems (apical and lateral)
– Region of specialized cells that undergo cell
division
give rise to:
apical- primary plant body, leaves
lateral- secondary plant body, wood and bark
Node, internode, axillary bud, leaf
Node – point of leaf attachment on stem
Internode – portion of stem between nodes
Axillary bud – dormant shoot at node with dormant apical meristem
Leaf (next week!)
Primary plant body
growth from shoot and root apical meristems (tips of
roots and shoots)
• primary tissues: epidermis, cortex, pith and primary
vascular tissues
• constitutes the herbaceous parts of the plant
Secondary plant body
growth from lateral meristems
• secondary tissues: wood, bark
• constitutes the woody, bark-covered parts of plants
modular growth
the same set of parts is produced over and over with modifications to make up the large complex features we see in all plant shoots for node, internode, axillary bud and leaf
Shoot system- plant organ system, reproductive vs vegetative
• Reproductive flowers fruits • Vegetative leaf (petiole, blade) stem (node, internode)
Root system- plant organ system
- Tap root
* Branch root
epidermis (cuticle, stomata, guard cells, trichomes)
- epidermis- outer layer
- waxy cuticle to prevent drying
- stomata for exchange of gases
- guard cells open or close stomata pore
- trichomes hairs that can be used for protection, reduce wind speeds, reduce water loss
pith
composed of soft, spongy parenchyma cells, which store and transport nutrients throughout the plant.
cortex
outer layer of a stem or root in a plant, lying below the epidermis but outside the vascular bundles
vascular bundles (xylem, vessel elements, pits, perforation plates, phloem, sieve elements, companion cells)
xylem- water transport
phloem- sugar transport
pits- allow water to flow
vessel elements- conduct water from soil through roots up to leaves
companion cells- genetic information that directs operation c-cells
sieve elements- the specialized parenchyma cells that conduct the sugary mix of fluid throughout the plant attached to companion cells
perforation plates- end wall of vessel element
leaf functions (5)
1) Photosynthesis (foliage leaves)
2) Protection
3) Support
4) Storage
5) Nitrogen acquisition (insect trapping)
blade
leaf, capture light from photosynthesis
petiole
attaches blade to the stem
simple leaf
no complete divisions into smaller sections called leaflets
compound leaf (pinnate, palmate)
leaf blade divided into smaller units- leaflets
pinnate- sections of rachis between the leaflets
palmate- leaflets stemed from one section, like a hand
leaflet
leaflets are sections of the blade divided
rachis
stemlike section between leaflets
mesophyll, palisade parenchyma, spongy parenchyma in eudicot leaf
mesophyll- middle leaf, chlorenchyma, many air gaps for CO2 to diffuse
palisade parenchyma- defensive, direct light down through top of leaf for better light penetration (upper layer)
spongy parenchyma- helps CO2 move in the leaf to get to cells, stomates on bottom of leaf (lower layer)
leaf veins (vascular bundles of xylem and phloem)
monocot- parallel, eudicot- reticulated
bud scales
protection, reduce frost, surround bud, specialized leaves
spines
protection, dead at maturity, made from sclerenchyma, modified leaves
leaf tendrils
support, 3 leaflets are tendrils without a blade, and grab onto a supporting structure
taproot
the single main root formed in the embryo in a seed and are retained in many eudicots to become the main and largest root of the plant
lateral root
emerge on the sides of downward growing tap roots or other dominant roots and typically function to spread the absorbing surfaces of the root system outward to increase the volume of soil occupied for uptake of water and nutrients
fibrous root system
usually found in monocots, dividing small roots of about the same size that serve to intensively exploit soil resources
root hairs
specialized elongated cells, these single-celled structures which are part of the epidermis serve to increase the absorptive area of the root and absorb water and nutrients from smaller pores in the soil
root cap
serves to absorb the frictional damage of the growing root tip as it expands through the soil pushed by the elongating cells behind the meristem
endodermis
specialized tissue surrounding the xylem and phloem and undifferentiated cells. protective layer of tissue formed outside the pericycle in primary roots. tissue forces absorbed water and dissolved ions through living cells and their semi-permeable membranes before arriving at the root xylem.
pericycle
tissue gives rise to new lateral roots, forming apical meristem
casparian strip
waxy structures on cell walls, part of endodermis, forces water and dissolved nutrients to pass through endodermis, preventing chemical ions getting into the plant
prop roots
specialized roots, above ground sections and stems, stabilize and add support to a plant on shifting or unstable surfaces, tropical
buttress roots
fig tree, platelike roots fuse to from thickened support structures for stability to heavy tropical trees
storage roots
radish, carrot, sweet potato. modified and used to store starch and sugars
primary growth of stem
eudicot- vascular bundles form a ring, monocot- vascular bundles don’t form a ring
xylem forms- inside direction of stem, pholem- outside
secondary growth of stem
secondary xylem to form wood
vascular cambium
meristematic cells, divides to produce secondary xylem
stolon
horizontal spread, above ground
secondary growth of stem
pro: adds capacity for transporting water and sugar
con: wood and bark are expensive for energy and nutrient resources
tuber
storage, short & fleshy horizontal stem (like potato)
cork cambium
secondary tissue, develops outside the phloem from cell divisions of another lateral meristem, bark
wood (secondary xylem)
dominant mass of woody stem
secondary phloem
outer margin of stem, lateral cell divisions
early wood
larger cells, thinner walls, produced early in the season, images have bigger holes
late wood
added in the fall are densely packed with small widths and thick cell walls, smaller cells, images have smaller holes. very thin layer in diffuse porous
bark
everything outside of vascular cambium
cork
outer bark
stolon
stem modification, horizontal spread, above ground
rhizome
stem modification, horizontal spread, winter survival, below ground
tuber
modified stem, storage, short & fleshy horizontal stem (like potato), the eyes of potatoes are nodes
thorn
modified stem, protection, sharp-pointed short shoots, protection of stems against herbivores, whole stems from axillary buds
bulb
modified stem, storage, below ground, short vertical stem, fleshy leaves
corm
modified stem, storage, below ground, vertical fleshy stem, papery leaves, winter survival
lenticels
modified stem, appearance of slits, wart-like or depressions, aid in gas exchange on stem (wood),
hyphae that forms sporocarps in Ascomycota
haploid and dikaryotic
hyphae that forms sporocarps in Basidomycota
haploid and dikaryotic
chromoplast
type of plastid found in cells of flowers and fruits that functions to hold colorful red and yellow pigments for attracting animals
mitochondria and chloroplasts have extensive internal membrane networks with associated enzymes attached to membrane surfaces. enzymes are positioned in this way onto these membranes
to optimize sequences of enzyme reactions
diffuse porous and ring porous
Ring-porous species have considerably larger pores in earlywood than in latewood of the previous and the same growth ring. Diffuse-porous species have vessels of approximately the same diameter throughout the growth ring.
both in angiosperms
