Comprehensive BIOL 1002 Exam 1 Study Guide: Evolution, Diversity, and Key Traits

What is the primary theme connecting all organisms?

All organisms are connected through common ancestry.

What is systematics?

The scientific study of biological diversity and its evolutionary relationships.

Define taxonomy.

The science of naming, describing, and classifying organisms.

What does phylogeny refer to?

The evolutionary history of a group of organisms, often depicted as a tree.

What is a taxon?

A named group of organisms at any rank (e.g., Mammalia).

What is a clade?

A group of organisms that includes an ancestor and all of its descendants.

List the taxonomic hierarchy from broadest to most specific.

Domain → Kingdom → Phylum → Class → Order → Family → Genus → Species.

What does a node in an evolutionary tree represent?

A common ancestor of the groups that branch from it.

What is binomial nomenclature?

A system for naming species using the format Genus + species (e.g., Homo sapiens).

What distinguishes Bacteria from Archaea?

Bacteria have peptidoglycan in their cell walls, while Archaea do not.

What is conjugation in prokaryotes?

The transfer of genetic material from one bacterial cell to another via a pilus.

Define quorum sensing.

A process where bacteria communicate using chemical signals to coordinate group behaviors.

What is a biofilm?

A structured community of microorganisms attached to a surface, encased in a self-produced matrix.

What are the shapes of prokaryotes?

Cocci (spheres), Bacilli (rods), Spirilla (spirals).

What is the primary method of reproduction in prokaryotes?

Binary fission, where the cell replicates its DNA and splits into two identical cells.

What are cyanobacteria?

Photosynthetic bacteria that perform oxygenic photosynthesis and are believed to be ancestors of chloroplasts.

What are viruses?

Acellular infectious agents consisting of genetic material in a protein coat; cannot reproduce independently.

What are viroids?

Infectious RNA molecules that infect plants, consisting of circular RNA with no protein coat.

What are prions?

Misfolded proteins that cause normal proteins to misfold, leading to neurodegenerative diseases.

What role do prokaryotes play in ecosystems?

They act as decomposers, nitrogen fixers, and can be involved in symbiotic relationships.

What is endosymbiosis?

The theory that certain organelles originated from free-living prokaryotes engulfed by a host cell.

What is the difference between photoautotrophs and chemoautotrophs?

Photoautotrophs use light energy and CO₂, while chemoautotrophs use inorganic chemicals and CO₂.

What is the significance of the taxonomic hierarchy?

It organizes biological diversity from broad categories to specific organisms.

What are pathogenic bacteria?

Bacteria that cause disease by producing toxins, invading tissues, or triggering immune responses.

How do prokaryotes extract energy?

Through cellular respiration (aerobic or anaerobic), fermentation, photosynthesis, or chemosynthesis.

What is the size difference between prokaryotes and eukaryotes?

Prokaryotes are generally smaller (~1-10 µm) compared to eukaryotes (~10-100 µm).

What is the role of gut bacteria?

They aid in digestion and can form symbiotic relationships with their hosts.

What are mitochondria believed to have evolved from?

Aerobic bacteria.

What are chloroplasts believed to have evolved from?

Photosynthetic bacteria, likely cyanobacteria.

What evidence supports the endosymbiotic theory for mitochondria and chloroplasts?

They have their own circular DNA, reproduce by binary fission, and have double membranes.

What type of nutrition do animal-like protists exhibit?

Heterotrophic (they ingest food).

Name an example of an animal-like protist.

Amoebas, Ciliates (e.g., Paramecium), Flagellates.

What type of nutrition do plant-like protists exhibit?

Photosynthetic.

Name an example of a plant-like protist.

Algae, Diatoms, Dinoflagellates.

What distinguishes fungus-like protists from true fungi?

They resemble fungi but are structurally and evolutionarily different.

What is the function of flagella in protists?

Whip-like tail for movement.

What is the function of cilia in protists?

Short, hair-like structures for movement and feeding.

What are pseudopods?

'False feet' — cytoplasm extensions for movement and engulfing food.

What positive ecological role do phytoplankton play?

They produce a large share of Earth's oxygen and form the base of aquatic food webs.

What negative impacts can some protists have?

They can cause diseases such as malaria (Plasmodium) and giardiasis (Giardia).

What is the main body structure of fungi called?

Mycelium, which is a network of hyphae.

What is chitin?

A polysaccharide found in fungal cell walls and arthropod exoskeletons.

How do fungi obtain nutrition?

They secrete digestive enzymes into their surroundings and absorb the nutrients externally.

What are the two main types of fungal reproduction?

Asexual (producing spores) and sexual (fusion of hyphae).

What is the significance of cuticles in plants?

They reduce water loss from the plant surface.

What is the role of stomata in plants?

They allow gas exchange while regulating water loss.

What do vascular tissues in plants transport?

Xylem transports water and minerals; phloem transports sugars.

What is the dominant life stage in nonvascular plants?

Gametophyte (haploid).

What is the dominant life stage in vascular plants?

Sporophyte (diploid).

What defines invertebrates?

Animals without a backbone or vertebral column.

What defines vertebrates?

Animals with a backbone or vertebral column.

What is bilateral symmetry?

Body can be divided into mirror-image left and right halves.

What are the three germ layers in triploblastic animals?

Ectoderm, mesoderm, endoderm.

What is the key characteristic of the phylum Porifera?

No true tissues (simplest animals).

What is the key characteristic of the phylum Cnidaria?

Presence of cnidocytes (stinging cells).

What is the key characteristic of the phylum Mollusca?

Presence of a mantle, foot, and visceral mass.

What is an acoelomate?

An organism with no body cavity, having solid tissue between the gut and body wall (e.g., flatworms).

Define pseudocoelomate.

An organism with a 'false cavity' that is not fully lined by mesoderm (e.g., roundworms).

What characterizes a coelomate?

An organism with a true body cavity fully lined by mesoderm (e.g., annelids, chordates).

In protostomes, what does the first opening in the embryo become?

The mouth.

In deuterostomes, what does the first opening in the embryo become?

The anus.

List two examples of protostomes.

Mollusks, annelids, arthropods.

List two examples of deuterostomes.

Echinoderms, chordates.

What are the four key characteristics of all chordates?

Notochord, dorsal hollow nerve cord, pharyngeal slits, post-anal tail.

What is the significance of the vertebral column?

It replaces the notochord as the main support and protects the nerve cord.

What evolutionary innovation allowed vertebrates to become active predators?

Jaws.

What adaptation allowed vertebrates to move onto land?

Terrestrial adaptations such as lungs and limbs.

What is the function of the amniotic egg?

It allows reproduction away from water by providing extraembryonic membranes.

What does endothermy allow animals to do?

Maintain a constant body temperature (e.g., birds and mammals).

What is the difference between conjugation and binary fission in bacteria?

Binary fission is asexual reproduction (one cell splits into two), while conjugation is the transfer of DNA between two cells.

Describe the endosymbiotic theory.

Mitochondria and chloroplasts originated from free-living prokaryotes that were engulfed by a host cell.

What are the three groups of protists and how do they obtain nutrition?

Animal-like (heterotrophic), plant-like (photosynthetic), fungus-like (absorptive).

Trace the evolutionary progression of plant groups.

Nonvascular → Seedless vascular → Gymnosperms → Angiosperms.

Why is pollen an important evolutionary adaptation?

It allows reproduction without requiring sperm to swim through water.

What is the taxonomic hierarchy from broadest to most specific?

Domain → Kingdom → Phylum → Class → Order → Family → Genus → Species.

What is the difference between an ancestral and a derived trait?

An ancestral trait is inherited from a distant ancestor, while a derived trait evolved more recently and is unique to a narrower group.

Correctly format a scientific name.

Genus capitalized, species lowercase, both italicized (e.g., Homo sapiens).

What is the significance of the alternation of generations in plants?

It describes the life cycle stages of sporophyte and gametophyte generations.

What are the key characteristics of sponges?

They have no true tissues.

What distinguishes cnidarians?

They possess cnidocytes (stinging cells).

What are the key traits of mollusks?

They have a mantle, foot, and visceral mass.

What characterizes arthropods?

They have an exoskeleton and jointed appendages.

What is a defining feature of echinoderms?

They have a water vascular system.