Download botany 306 - Department of Ecology, Evolution, and Organismal

Name: ________________________
BIOLOGY 366
PLANT SYSTEMATICS
EXAM II KEY
GYMNOSPERMS THROUGH ROSIDS
100 POINTS TOTAL (LECTURE 50, LAB PRACTICAL & KEYOUTS 50)
SECTION 2: Short answer (30 points total). Be as precise as possible in your answers.
1. List three synapomorphies for angiosperms. (3 points)
Several possibilities, including: flower, carpels, fruit, ovules with two integuments,
reduced female gametophyte (no archegonium), double fertilization, 3n endosperm,
stamens with two pairs of lateral pollen sacs (thecae), pollen 3-nucleate, pollen tube, and
phloem of sieve tube members each with 1 or more companion cells derived from the
same mother cell.
Also acceptable, although not strictly synapomorphic: vessels.
2. Gymnosperm families. A. Fill in the table to show the characters that differentiate the
four families of gymnosperms that we studied. (5 points)
Family
Character
Leaf shape
Gingkoaceae
Pinaceae
Cupressaceae
Taxaceae
fan-shaped
needle-like
needle-like
needle-like
Branch structure
long and short
shoots
no
long only or long
and short shoots
yes
long shoots only
long shoots only
yes
no
not applicable
inverted
uninverted
not applicable
tan, fleshy
brown, hard
brown, hard
red, fleshy
Ovules in cones?
Ovule position
on cone scale
Seed coat
color/texture
3. The Poaceae, Juncaceae and Cyperaceae are important in many habitats, especially
wetlands, and they often grow side by side. Write a dichotomous key (bracketed or
indented, two characters per lead) for these three families. (6 points)
Several possibilities:
1. Flowers in cymose inflorescences; fruit a many-seeded capsule……….……Juncaceae
1. Flowers in spikelets, these variously grouped in compound inflorescences; fruit
single-seeded, an achene or caryopsis…………………………………………………..…..2
2. Leaf sheaths closed; flowers subtended by a single bract; fruit an achene
……………………………………………………………….………………Cyperaceae
2. Leaf sheaths usually open; flowers enclosed by two bracts (lemma and palea);
fruit a caryopsis…………………………………………...........…………….Poaceae
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Name: ________________________
4. Match each taxon on the left with the best or most appropriate adaptations from the
column on the right. Put your answer in the 2nd column. Each taxon and adaptation
must be used only once. (1 point each, 9 points total)
Adaptations/Characters
Trees; solitary flowers;
elongated receptacle
Spadix subtended by a
spathe; netted leaf venation
Usually equitant leaves; 3
stamens; inferior ovary
Epicalyx; calyx valvate;
stamens monadelphous or
polydelphous
Latex often present; flowers
unisexual; 3-carpellate
gynoecium
Usually herbs with dissected
leaves; numerous stamens;
apocarpous gynoecium
Flowers with a conspicuous
labellum; pollinia
Ocrea present or absent;
tepals connate; fruit usually a
3-sided achene or nutlet
Floating aquatics; enlarged
receptacle
D
Taxon
A. Nymphaeaceae
H
B. Orchidaceae
I
C. Ranunculaceae
F
D. Magnoliaceae
G
E. Polygonaceae
C
F. Malvaceae
B
G. Euphorbiaceae
E
H. Araceae
A
I. Iridaceae
5. Among the angiosperm families and genera we have covered to date (ANITA grade
through the rosids), we have seen examples of the independent evolution of various
features or syndromes and also the modification of homologous structures for different
functions. Give one example of each, indicating which taxon or taxa are involved, and
explaining what feature(s) have been modified for which function. (4 points)
A) Example of independent evolution: Many possible answers, including: wind
pollination in families such as the Juncaceae or Cyperaceae and Poaceae or between
these and Ranunculaceae, Sapindaceae, Salicaceae and others; latex in Nymphaeaceae
and Euphorbiaceae; spikelets in Cyperaceae and Poaceae.
B) Example of modification of homologous structures for different functions:
Again, many possible answers, including: modification of photosynthetic leaves into
brightly colored bracts as in Araceae or Euphorbiaceae; modification of leaves or
leaflets into tendrils as in Fabaceae; modification of leaves into spines as in Cactaceae.
6. What is an herbarium and why are herbaria important to biodiversity studies? (3
points)
A herbarium is essentially a plant library, containing pressed and dried specimens of
plants and also usually fungi. The specimens help to document the geographic
distribution of species, their habitats, and range of variation, and therefore provide
fundamental knowledge for analysis of patterns of biodiversity.
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Name: ________________________
SECTION 3: Fill in the blank (20 points total; 1 point each). Provide the appropriate
term.
1. The ___Amborellaceae___ (family) are sister to all other angiosperms.
2. A well-developed hypanthium can be found in the __Rosaceae__ (family). Other
possible answers include: Fabaceae, Saxifragaceae and technically the Cucurbitaceae,
Iridaceae, Onagraceae, and Orchidaceae.
3. Within the Fabaceae, a well differentiated floral banner, keel and wings are
characteristic of the _____Faboideae______ (subfamily), whereas the
____Mimosoideae____ (subfamily) usually have pinnately compound leaves and showy
stamens.
4. Seeds of _Gingkoaceae_ (family) were probably dinosaur-dispersed. Also acceptable:
Cycadales or Cycadaceae or cycads; Taxaceae.
5. The combination of tetramerous flowers, six stamens, a gynophore and a 2-carpellate
gynoecium is diagnostic for the __Brassicaceae__ (family).
6. A megasporophyll bearing marginal ovules is homologous to the angiosperm
____carpel____.
7. __Parallel leaf venation__ and __trimerous flowers__ are synapomorphies for the
monocots. Also acceptable: one cotyledon, atactostele, adventitious root system, lack of
a vascular cambium, flowers pentacyclic, sieve tube members with cuneate protein
crystals.
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Name: ________________________
8. Onions and garlic are in the ___Alliaceae___ (family); their characteristic taste and
smell come from __sulphur-containing__ compounds.
9. The presence of a perigynium is a synapomorphy for the genus __Carex___.
10. When we eat peanuts or kidney beans, we are eating the __seeds__ of the plant.
11. Eudicots are defined by the presence of ___tricolpate___ pollen.
12. Apocarpy and laminar stamens are considered __plesiomorphic__ within the
angiosperms.
13. The __Fabaceae__ (family) are important ecologically in part because of their
nitrogen-fixation symbiosis with bacteria.
14. A compound ovary with 5 stigmas and 5 locules is inferred to consist of _5_ carpels.
15. If a flower has a superior ovary and no adnation is present, the other flower parts are
described as __hypogynous__ relative to the ovary.
16. The presence of nectar glands in flowers of Salix indicates __insect__ pollination,
whereas the lack of glands in the flowers of Populus indicates __wind__ pollination.
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Name: ________________________
SECTION 4: LABORATORY PRACTICAL (30 PTS TOTAL; 2 PTS EACH)
Name: ___________________KEY____________________
TA: _______________
1. Cactaceae
9. Trifolium
2. Rosaceae
10. Araceae
3. Juniperus
11. Brassicaceae
4. Amaranthaceae
12. Malvaceae
5. Poaceae
13. Liliaceae
6. Carex
14. Typha
7. Euphorbia
15. Acer
8. Orchidaceae
Bonus points (3 points; 1 point each)
1) Family? Rosaceae
2) Describe carpel fusion in this flower? Apocarpous
3) Name the unit fruit. Achene
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Name: ________________________
SECTION 1: KEYOUTS (20 PTS; 10 PTS EACH)
Key each of the two plants out as instructed using the keys in your lab manual. For
partial credit, be sure to write your way through the keys using the couplet numbers.
1. Family, genus
1b →6b →43b →135b →141b →142a →143a →144b →160a →161b →162b →163a
→Bacopa in Plantaginaceae
2. Family, genus
1b →6a →7b →18b →35a →36a →Ranunculaceae
or
1b →6a →43a →44a →45a →46a →47b →49b →51b →52b →54a →55a
→Ranunculaceae
1b →2a →3b →4a →5b →Delphinium
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