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BIO SCI 94 Study Guide - Midterm Guide: Sponge, Tunicate, Cestoda


Department
Biological Sciences
Course Code
BIO SCI 94
Professor
Nancy Burley
Study Guide
Midterm

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Bio94 Midterm 2 Study Guide
Lecture #8: Protists
Question
Answer
What are the characteristics of protists?
They have membrane-bound organelles
(including mitochondria and chloroplast),
cytoskeleton, pseudopodia for movement,
undergo meiosis, and can be unicellular or
multicellular. They also have a flexible cell
surface to be heterotrophic.
What is the evidence of the endosymbiotic
theory?
Mitochondria are the same size as alpha-
proteobacteria, they replicate via fission, have
their own ribosomes, have two membranes,
and have a similar genome sequence to
proteobacteria. Chloroplasts also likely
evolved this way (originally cyanobacteria)
but from secondary symbiosis (4
membranes).
What are three of the protist innovations?
1) Structures for support and protection:
diatom, dinoflagellate, and
foraminifera
2) Sexual reproduction via meiosis and
syngamy: produces more viable
offspring, advantageous in stressful
environments
3) Multicellularity: cell communication,
specialization, and adhesion
List the ecological roles of protists.
- Base of the food chain ex)plankton
and kelp in the ocean
- Pathogens and parasites (plasmodium
causes malaria, water mold and
potato famine)
- Mutualists: dinoflagellates and coral
- Decomposers: plasmodial slime mold
List the important uses of protists
Marine food chains, source of limestone,
component of petroleum and sedimentary
rock, can cause algal blooms, carbon cycle!
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Lecture #9: Plants
What synapomorphies do green algae share
with land plants suggesting common
ancestry?
Both have chloroplasts with chlorophyll alpha
and beta, same cell wall composition, both
store starch, and they have the same sperm
structure. Land plants evolved from
freshwater forms of algae.
What are land plants called?
Embryophyta
What were the benefits and challenges of the
transition to land?
Benefits: more sunlight, more CO2
Challenges: dehydration
What trends occur throughout the evolution in
plants?
Increasing independence from water,
increasing size, increasing parental
contribution to zygote.
What are the early innovations of land plants?
Found in algae: spore and sporopollenin
Found in land plants: cuticle, stomata,
alternation of generations.
Describe the alternation of generations.
A haploid gametophyte produces gametes,
which undergo syngamy to form a diploid
zygote. This undergoes mitosis to form a
diploid sporophyte, which undergoes meiosis
to form haploid spores, which in turn undergo
mitosis to form another gametophyte.
What are the characteristics of nonvascular
plants? Give an example.
Nonvascular plants have no roots (rhizoids
instead), stems, or leaves. They are resistant
to desiccation but need water for
reproduction. They are also small.
Mosses (bryophyta) which are gametophyte
dominant and the zygote is retained on the
plant. Only group that is gametophyte
dominant.
What are the characteristics of seedless
vascular plants? Give an example.
Seedless vascular plants have vascular
tissue, lignin for strength, and tracheids and
roots for water transport.
Ferns (pteridophyta) are sporophyte
dominant.
What are the characteristics of seed plants
(gymnosperms-naked seed)? Give an
example.
Possess seeds (embryo+nutrition+seed coat),
and are heterosporous (microspores and
megaspores), have wood and vessels.
Includes cycads, ginkgos, conifers, and
gnetophytes.
What are the characteristics of angiosperms
(enclosed seed)?
They have flowers (male stamen and female
carpel), and zygote is provisioned with
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