BIOL 108 Midterm 2

What are Ciliates?

A diverse group of unicellular alveolates

What are cilia used for in ciliates?

Locomotion and feeding

What is unique about Rhizarians?

They are chemoheterotrophs that use THREAD-LIKE pseudopodia to capture prey (through phagocytosis)

Archaeplastida

Photosynthetic supergroup

What kind of cell walls do archaeplastida have?

Cellulose-based cell walls

What classifies something as an algae?

Photoautotrophic eukaryotes that are NOT plants

Unikonta

A supergroup that consists of chemoheterotrophic protists

How do Amoebozoans differ from Rhizarians in terms of pseudopodia?

Amoebozoans have lobe/tube shaped pseudopodia, whereas Rhizarians have thread-like pseudopodia

Two main lineages of slime moulds?

Plasmodial slime moulds and cellular slime moulds

Tubulinds are a subgroup of which supergroup?

Amoebozoans

What are Enatomoebas and what disease are they responsible for?

Intestinal parasites that cause amebic dysentery

Charophytes

Freshwater green algae

6 features of a living thing:

Organization, metabolism, response to stimuli, homeostasis, adaptation, reproduction

Organization (definition of life)

Structurally composed of one or more cells

Metabolism (definition of life)

A way to manage energy and materials through chemical rxns

Response to stimuli (definition of life)

Changes in growth, movement, and changing chemical rxns

Homeostasis (definition of life)

Maintaining of internal chemical and/or thermal consistency relative to variation of environment

Adaptation (definition of life)

The ability to change over time in response to the environment

Reproduction (definition of life)

The ability to produce new individual organisms

What are the three major eons

Archaean, Proterozoic, Phanerozoic

Within the phanerozoic eon, what are the three eras

Paleozoic, Mesozoic, Cenozoic

What two eons make up the Precambrian period

Archaean and Proterozoic

Which extinction bounds the Paleozoic and Mesozoic eras?

Permian mass extinction (The Great Dying)

Two lineages of seed plants

Gymnosperms and Angiosperms

______ have “naked seeds” like cones

Gymnosperms

______ have “vessel” seeds like in fruit

Angiosperms

Four extant phyla of gymnosperms

Cycadophyta, gingkophyta, gnetophyta, coniferophyta (much more diverse)

Gymnosperms form a ________ group

Monophyletic

Cycads are unique among seed plants in that they have…

Flagellated sperm

Phylum _________ has only one extant species

Gingkophyta

Gingkophyta (G. biloba) is pollinated with…

Wind (flagellated sperm)

Trees that are _______ can carry out photosynthesis year-round

Evergreens

T/F: Phylum Coniferophyta are comprised of only conifers

False

3 F’s of the life cycle of Angiosperms

Flowers, double Fertilization, Fruits

Flowers are specialized for ______________

Sexual reproduction

Infloresences

Clusters of complete flowers that looks like one big one (eg. Sunflower)

Which extinction bounds the Mesozoic and Cenozoic eras?

The Cretaceous mass extinction, which killed non-avian dinosaurs

Cause of the Permian mass extinction?

Unknown, but speculated to be volcanic activity

Cause of the Cretaceous mass extinction?

Meteorite

Adaptive Radiation is…

Rapid evolution of diversely adapted species from an ancestral species

What can lead to adaptive radiation?

Mass extinctions, evolution of novel characteristics (eg. photosynthesis and flight), colonization of new regions

How do Archaea cell walls differ from bacterial cell walls? How are they similar?

Archaea cell walls lack peptidoglycan but have structural polysaccharides and proteins like bacteria

Four major adaptations of prokaryotic success

Cell-surface structures, endospores, motility, simple internal organization and DNA

What is a bacterial capsule?

Sticky layer of polysaccharides or proteins SURROUNDING the cell wall

How can a capsule help with prokaryotic survival?

They help them stick to surfaces and each other, which can help form adhesive biofilms (communities), and protect against desiccation.

What are the different cell-surface structures of prokaryotes?

Capsules, fimbriae, and pili

What do fimbriae do?

Help prokaryotes adhere to surfaces

What do pili do?

The sex pili allow for exchange of DNA between prokaryotes

How might a prokaryote be able to survive a long period of unfavourable conditions?

Forming a metabolically inactive endospore

How might the simple internal organization of a prokaryote contribute to survival?

Rapid reproduction and they won’t need as much nutrients

Three factors that contribute to prokaryotic genetic diversity

Rapid reproduction, mutations, and genetic recombination

How do prokaryotes reproduces

Frequent binary fission

Why do mutations accumulate so quickly in prokaryotic populations?

Because they reproduce so rapidly

T/F: Prokaryotic DNA mutate at a faster rate

False

What is HGT (Horizontal Gene Transfer)?

Movement of genetic material between cells by mechanisms OTHER THAN PARENT-TO OFFSPRING

Types of genetic recombination in prokaryotes?

Transformation, transduction, and conjugation

Difference between transformation and transduction?

Transformation is when a viable cell takes up DNA fragments or plasmids. Transduction is when a bacteriophage transfers DNA

Obligate aerobes

Rely on O2 for cell resp; obligated to do aerobic resp

Obligate anaerobes

Inhibited by O2, so instead use fermentation or anaerobic resp for energy; obligated to do anaerobic resp

Facultative anaerobes

Can switch between using O2 and not using O2 depending on availability

Proteobacteria are Gram-____

Negative

A prokaryote has a close relationship with a eukaryotic host, living in root nodules and fix nitrogen. What group would it fall into?

Proteobacteria

The origin of which organelle is linked to Proteobacteria

Mitochondria

Which bacterial group is ENTIRELY DEPENDENT on a host for survival and reproduction?

Chlamydias

Organisms that entirely depend on a host for survival and reproduction are called…

Obligate parasites

Which bacterial group is known for their spiral shape?

Spirochetes

Mode of nutrition of Spirochetes

Heterotrophic

Which bacterial group is photoautotrophic?

Cyanobacteria

Bacterial decomposers in soil are most likely

Gram-positive bacteria, like Actinomycetes

Endosymbiont

Any organism living INSIDE the body or cells of another organism

In the Serial Endosymbiotic theory, which features of a cell first formed by infoldings of plasma membrane?

The ER and nuclear envelop (endomembrane systems)

In the Serial Endosymbiotic theory, which prokaryote was the first key endosymbiont and what organelle is this now?

The alpha-proteobacterium, which became the mitochondria

In the Serial Endosymbiotic theory, what was the second key endosymbiont and what was its significance?

The cyanobacterium, which utilized light and CO2 (becoming the chloroplast)

What is the difference between primary and secondary endosymbiosis

Primary is when a prokaryote is eaten by another prokaryote or eukaryote, secondary is when a eukaryote is taken up by another eukaryote

Four major supergroups of eukaryotes

Excavata, SAR, Archaeplastida, Unikonta

What is the closest living relative to plants?

Charophytes

What do charophytes and plants have in common?

Both have circular rings of proteins embedded in the plasma membrane that synthesize cellulose, and their flagellated sperm structures are similar

What clade includes charophytes and plants?

Streptophyta

What is another name for an embryophyte?

A plant

What are the main challenges of transitioning from aquatic to terrestrial

Desiccation, lack of structural support, and reproduction and dispersal (without water)

Coenocytic structure

Aseptate; lack septa or dividing walls within their hyphae

_______ fungi have separated cell nuclei in hyphae

Septate