Unit 2 pt.2 Flashcards
GAE 4 - half of lecture 17 (90 cards)
1
Q
What is primary growth in plants?
A
allows a plant to grow tall, found in woody and herbaceous plants
2
Q
What is secondary growth in plants?
A
allows a plant to grow wide, generates the tissue found in ONLY woody plants
3
Q
What is wood made up of?
A
secondary xylem
4
Q
What is bark made of?
A
all the tissue that is on the outside of the vascular cambium (the secondary phloem/ leftovers of primary phloem, cork, and periderm)
5
Q
If something is carved into a tree, will the words get taller, wider, or both?
A
The words will get wider b/c the outside (bark) of the tree is expanding out while height is seen at the tips of the tree
6
Q
What does the vascular cambium make?
A
The secondary xylem and phloem
7
Q
What makes the cork?
A
The cork cambium
8
Q
In flower development, what happens when A is expressed?
A
A will prevent C from presenting
9
Q
In the ABC model of flower development, what does A produce?
A
sepals and petal whorls
10
Q
In the ABC model of flower development, what does B
produce?
A
Petals and stamen whorls
11
Q
In the ABC model of flower development, what does C produce?
A
stamens and carpel whorls
12
Q
B+C=?
A
Stamen
13
Q
A+B+?
A
petals
14
Q
What is the mycelium?
A
the mat of hyphae
15
Q
What is the individual fungal filament called?
A
hypha
16
Q
How do fungal life cycles differ from other eukaryotes?
A
Some have dikaryotic stages (plasmogamy and karyogamy)
17
Q
How have terrestrial fungi adapted?
A
almost all multicellular, no flagellated cell (so don’t
need water), and parallel reproductive structures
18
Q
What are some benefits of fungi?
A
disease treatment, has been genetically modeled (helpful since it is the best characterized
genome of all eukaryotes), food, fermentation, etc.
19
Q
How are fungi harmful?
A
can attack/kill plants and animals (pathogens and parasites)
20
Q
Plasmogamy and karyogamy in fungi
A
21
Q
Isogamy vs anisogamy in fungi
A
22
Q
What are the major features that differentiate fungi from other eukaryotes?
A
chitin in cell wall, glycogen (energy storage), and absorptive heterotrophy
23
Q
What is the general eating strategy for fungi?
A
they usually secrete digestive enzymes and then absorb the nutrients
24
Q
What is a chemoheterotroph?
A
Digestion happens outside the cell + absorption
25
Saprobes?
feed on dead organic matter
26
Parasite?
feed on living organic matter
27
Mutualists?
Live cooperatively (in a way that net benefits both parties) with live organism
28
True or false? There are both single-celled and multicellular fungi
True
29
What are the 6 major groups of fungi?
Microsporidia, chytrids, zygospores, fungi, arbuscular mycorrhizal fungi, sac fungi, and club fungi
30
True or false? Most lineages do not contain at least some single-celled species
or go through single-celled stages
false
31
What is the general fungi life cycle?
asexual reproduction *haploid* and sexual reproduction *haploid, heterokaryotic, and diploid*
32
Traits of chytrids
- small (uni- or multi-cellular, aquatic)
- Coenocytic (has multiple nuclei in one cell)
- absorptive feeding (saprobes or parasitic)
- chitin in cell walls (amino-sugar polymer)
- mobile asexual spores (flagellated zoospores)
33
Reproduction cycle of chytrids?
- sporangium release flagellated haploid (n) zoospores
- zoospores grow into multicellular haploid chytrid (still haploid (n))
- female and male gametangium grow on the same chytrid and when there is sexual reproduction will release zoospores that fuse
- **In fertilization, plasmogamy and karyogamy happen at the same time**
- This makes a *diploid* (2n) zygote, that will become a multicelluar **diploid** chytrid (2n) -meiosis= sporangium for asexual reproduction
34
life cycle of zygospore fungi
- sporangium release spores (each spore will become new mycelium)
- the hypha will have - or + mating type
- when the - and + mating type hypha come in contact it will create a (n) *haploid* gametangia
- this gametangia will first do plasmogamy **THEN** karyogamy during the fertilization (2n - multiple haploid)
- the zygosporangium (multiple diploid nuclei
- the hypae holding it will eventually die and the zygospore is chill in its unicellular stage until its ready to do meiosis and start the process again
35
Sexual life cycle of Ascomycetes
- The ascus produces ascospores that germinate (extend - n)
- There will be a - and + mating type hyphae
- when the mating structure comes in contact with the opposite type plasmogamy happens
- There is also dikaryotic mycelium (n+n) as well as haploid hyphae (n) present
- The ascoma (fruiting body) forms has has the dikaryotic asci (n+n) just chilling
- next is fertilization (karyogamy) where the nuclei becomes fused
- zygote undergoes meiosis and then mitosis to make new ascus and ascospores
36
sexual life cycle for club fungi?
- The basidium produces basidiospores that are either (mating type 1 or 2) **depending on the type of club fungi, there could be hundreds of mating types** *haploid*
- the mycelial hyphae fuse (plasmogamy) and are found in the basidioma (fruiting body)
- the gills are lined with basidia that contain nuclei (dikaryon stage)
- fertilization then karyogamy = fused nuclei
- meiosis to make the basidium and basidiospores
37
True of False? The plant-fungi mutualism was likely
essential for land plant success
True
38
Are chytrid oogamous?
No, they are isogamous and both are mobile
39
What does fossil evidence suggest for land plants and terrestrial fungi?
That the terrestrial phyla may have evolved as the symbionts of the first land plants = some became decomposers later
40
What are the 3 important decomposers?
zygote, sac, and club fungi
41
What is type 1 mutualism
arbuscular mycorrhrizal fungi are symbiotic mutualist with plant roots
42
What ion uptake is increases with the fungal + root relationship
PO4 3-
43
ectomycorrhizae?
hyphae extends into the soil and in-between the cell
44
Arbuscular endomycorrhizae
hyphae extends into soil but also into cell wall and comes in contact with plasma membrane
45
With lichen, asexual repro. involves the formation of what?
Soredia, small clusters of hyphae with embedded algae that can break off and grow somewhere else
46
What are three key processes that occur early in development?
proliferation, movement/expansion, and differentiation
47
How did cloning help show that all cells have the same DNA
with cell specification and differentiation determined by gene
expression?
it showed that mature cells contain all the genes in the genome
48
What is gastrulation?
major cell movements create embryonic tissue layers that will become organs (depends on cell movement and differentiation)
49
What is neurulation?
Process of forming the neural tube = central nervous system (in vertebrates)
50
What is segmentation?
the mesoderm forms somites which lay the ground work for where vertebrae, deep skin (dermis), and back muscles go
51
What are two ways to determine cell fates?
1. signals come from the cell itself (cell autonomous, signals can be put into the egg by the mother (dolly) - cytoplasmic determinant)
2. signals come from cells (cell signaling and induction) *signaling cells make diffusible proteins or other molecules that alter gene expression in near or far cells. amount of inducers getting to receptor determines whether gene is expressed*
52
What are some approaches that developmental biologists use
to understand cell determination?
surgical manipulation (embryology)
- bicoid in anterior polarity & discovery of vertebrate limb polarity)
Perturbation of genes (developmental genetics)
-forward: screening through collections of mutants to figure out what key genes are different and cause it
-reverse: inactivate specific genes and see what they do
53
How do you test whether genes or tissues are necessary or sufficient?
Necessary = if you remove it, the trait is gone completely
Sufficient = if you add it, you will gain a trait
54
How does this relate to master regulatory genes? Describe a key
experiment used to show how they work.
Master reg, genes are necessary and sufficient
Experiment: Eyeless/Pax6 ( reg. gene that signals cells to make eyes (if the gene is knocked out, the eye won't be made) and if you put pax6 somewhere else and eye will be made there (ie sufficient and necessary)
*Wg = wing, you take out Wg = lose the wing*
55
What is cell proliferation?
- cells divide (mitosis)
- timing, orientation, and rate of cell division is regulated
- cells die during normal development (apoptosis)
56
What is the difference in plant seeds and animal embryos when it comes to cell proliferation?
animal embryos cells cleave while plant seeds grow
57
What is the difference between intercalation, migration, and differential expansion in cell movement?
-intercalation is when two layers of cells smush into one another to create a single layer
-migration: when one cell types moves to another cell type
- differential expansions, when different layers of cells expands/grow at different rates. (**only plants and fungi do this**)
58
Why do cells loose ability to become any cell type in cell differentiation?
During development, cells will loose their ability to become whatever cells b/c of the expression of distinct gene sets, and some stem cells need to remain unspecialized
This is decided by mRNAs (proteins restricted to certain cell types), signals from other tissues, and environmental changes
59
What are the steps of gastrulation?
1. after cell division, embryo starts as a hollow ball of cells called a blastula (ectoderm, mesoderm, and endoderm)
2. the cells that will become the endoderm infold (ingavination) into the hallow of the ball to become the mouth to butt (anus) hole (alimentary canal)
3. the mesoderm cells move around and become the mesenchyme
4. the mesenchyme pretty much becomes an anchor by making extensions to the ectoderm
5. the archenteron (actual tube part for the canal) stretches to meet the ectoderm
60
True or false? Most animals have 2 tissue layers
False, most animals are trophoblast (3 tissue layers)
61
What is the difference between protostome developments and deuterostome development?
Clevage: (both 8-cell stage) P-spiral and determinate, D-radial and indeterminate
Coelom formation: P- forms from the split in mesoderm, D-forms by mesoderm outpocketing (folds in tube thing becomes coelom)
Fate of blastopore: P-mouth comes from blastopore, D-mouth forms from secondary opening (probably why we talk shit, cause our asses formed first)
62
How does gastrulation work in a flat yolk like a chicken?
1. mini tracing streak is formed
2. cells migrate at the streak and elongate it
3. streak narrows and lengthens
4. streak evolves to a grove and becomes the chick blastopore
5. cells move inward through the groove and Hensen's node (looks like the top of the ass crack)
6. cells made at Hensen's node pass through the gastrula and move forward to make the head strucutre and notochord
63
How are neural tubes formed
ectodermal layer invaginates and rolls up...like rolling your tongue)
64
How is notochord formed?
Endodermal layer invaginates and rolls up
65
What does the body plan specify after Gastrulation, Neurulation,
Segmentation?
head, limbs, organs (master regulatory genes are super important here)
66
What do master regulators do?
- important transcription factors that guide gene expression to make an organ
67
What is important about bicoid in Drosophilia?
- bicoid is more expressed in anterior (head) part and decreases as it gets to the butt
-bicoid gradient turns on the "head" gene in egg (deposited by maternal cell (cell autonomous), translation makes bicoid protein)
- Bicoid is sufficient as seen by testing of adding genes in random parts and the head being made there
68
Embryology example?
- ZPA (zone of polarizing activity) when shh is added to a new ZPA on a limb bud it causes double hands
-ZPA expresses Shh gene and is a master reg. (if ZPA cells aren't secreting shh = no limbs, but if they are = limbs)
69
What was the major evolutionary theme for plants?
Moving from aquatic areas to land environments
70
What was the major evolutionary themes of fungi?
symbiosis (ranging from mutualism to predation)
71
What was the major evolutionary theme for animals?
different groups within animalia gaining the ability to move in complex ways, becoming terrestrial (tikiitaka or wtv that thing is called) and high metabolic rates
72
What are the key attributes of an animal?
- multicellular and eukaryotic
- Heterotropic (usually aerobic)
- have openings to bring in food (mouths) *and internal digestion for the most part *
- movement by using muscles
- Often have a nervous system and some kind of brain
- The body plan is planned out/decided by Hox genes
- unique extracellular matrixes (different proteins) and cell adhesion
73
How and when did animals evolve?
- protist ancestors (choanoflagellates) - choanocytes are a shared cell type (collar of microvilli, flagellated cells (deadass looks like a tampon), and colonial dependency on resource availability)
74
Why did the Cambrian explosion happen?
evidence that almost all modern bilaterians were found in this time period
it also seems like the modern phyla diverged before the Cambrian period, but there was a crazy fast diversification during the explosion
75
Explain where animals are found on the phylo. tree?
Animals are opisthokonts and are pretty related to choanoflagellates
76
Why are choanoflagellates important to understanding animal evolution?
Choanoflagellates protists closely resemble chonocytes (found in sponges). Choanoflagellates live in colonies (rosettes) and use their flagellum to create a current that sucks food in. Choanocytes use the same method (on a larger scale) to pull water/food into the pores on the sponge
77
Based on fossil records, when was visible life seen?
Phanerozoic era (euk, ~ 1.5 bya and multi. euk. = less than 1 bya ago)
78
What is so important about cells sticking together in animal evolution?
cell-cell adhesion and cell-matrix adhesion means that mechanical stresses are spread across multiple cells instead of a few and connection to an extracellular matrix takes in most of the brunt of that mechanical stress.
plus the network of proteins and other molecules that surround + support cells/tissues (helps with sticking together, communication, movement, signaling, growth, etc. )
79
True or false? Human genes a pretty new in terms of composition
False, a lot of human genes are shared with unicellular animal ancestors (53% of genes are shared across eukaryotes) *if it ain't broke, don't fix it, right?)
80
What are the 6 features of the animal body plan? (g,esbbn)
1. symmetry (sometimes)
2. gasturlation order
3. body cavity strucutre
4. body segmentation
5. external appendages
6. nervous system
81
What are the 6 animal groups?
sponges, ctenophores, placozoans, cnidarians, protosomes, and deuterosomes (*there is a polytomy here bc we don't know what the hell the common ancestor was)
82
What is the variation in symmetry?
- no symmetry (sponges/placozoans)
- Bilateral (bilaterians)
- radial (ecinoderm *pentaradial* and cnidaria)
- biradial (ctenophores)
83
What is the variation in gastulation?
- Monoblasts: ecto
- Diploblasts: ecto and endo
- Triploblasts: ecto, meso, and endo
-Protosomes: mouth first then anus
- Deuterosomes: Ass first then mouth (doodoo = butt first)
*Mesoderm evolved right before protostomes and deuterostomes diverged*
84
What variation is there for body cavities?
The formation of the coelom can happen in 2 ways:
- deuterostomes: when the archenteron folds in, two little "bubbles" outpocket and then pinch off to make the coelom
- protostomes: when the archenteron folds in, at the very bottom (looks like the bottom of a horseshoe), the mesoderm starts forming and eventually grows up and alongside the walls of the infolding and ectoderm
85
What are the variations of the coelom?
- acoelomate: there is no coelom b/c body cavities aren't enclosed (no fluid-filled cavity) *flatworms*
-pseudocoelomate: fluid-filled and enclosed by mesoderm on the outside only *roundworms*
Coelomate: fluid-filled + mesoderm encloses cavities on both sides *earthworms* the ol' wombo combo
86
What are the two major groups of protostomes?
ecdysozoans (eck-du-suh-zoans) and lophotrochozoans (lo-fo-tro-co-zoans)...scientist truly playing in our faces when naming these things fr
87
What did the earliest fossil animals tell us?
ancestral sponges from site in Southern Australia ~600 mya had no specialized cells
88
What was the earliest bilaterian trace fossil?
"trackways" - narrow burrows from wormlike animal 585 mya
89
What were the most recent Ediacaran fossils?
Simple radial forms, some had body segments, with bilateral symmetry (565-542 mya)
90
Why was there a "sudden" appearance of the modern phyla?
two main ideas that pushed for diversification:
- internal: there was a threshold of complexity (needed to evolve the "toolkit" (genomic- master regulators) to get past the threshold in stem lineages and the evolution of homeobox genes
-external: evolutionary arms race, increase in O2 (large size = more complex), extinction = more niches available
