SBI3U Biology Test Review (DL1-DL16)

Comprehensive review flashcards covering SBI3U Biology review topics DL1 through DL16, including taxonomy, evolution, cladograms, cell types, domains, viruses, microscopes, protists, plants, fungi, and animal phyla.

How does the morphological species concept identify a species?

Species are identified using physical appearance or structural traits.

How does the biological species concept identify a species?

Members can interbreed naturally and produce fertile offspring.

How does the phylogenetic species concept identify a species?

Species are identified by evolutionary history and ancestry.

What is the correct taxonomic order from broadest to most specific?

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

What are the rules for writing a scientific name using binomial nomenclature?

Use a two-part scientific name consisting of Genus species: capitalize the genus, lowercase the species, and italicize both when typing or underline them separately when handwriting.

What is a dichotomous key and how is it structured?

It is an identification tool with two contrasting choices at each step.

What is the difference between anatomical and physiological evidence for evolutionary relationships?

Anatomical evidence compares physical structures such as bones, body parts, and internal anatomy, whereas physiological evidence compares how bodies function, such as enzyme activity, proteins, or hibernation patterns.

How do homologous and analogous structures differ, and what evolutionary patterns do they illustrate?

Homologous structures share underlying anatomy inherited from a common ancestor but may serve different functions (e.g., human arm and whale flipper), illustrating divergent evolution. Analogous structures share similar functions but evolved independently (e.g., bird wing and insect wing), illustrating convergent evolution.

What is the difference between divergent evolution and convergent evolution?

Divergent evolution occurs when related lineages become increasingly different after splitting from a common ancestor, while convergent evolution occurs when distantly related organisms independently evolve similar adaptations.

In a phylogenetic tree or cladogram, what do a node and the root represent?

A node represents a branching point that marks a common ancestor, while the root represents the ancestral starting lineage shown in a rooted tree.

What is a derived trait in phylogenetic analysis?

An evolutionary feature that arises in a lineage and can be shared by descendants.

How are closest relatives determined when reading a cladogram?

They are the pair that shares the most recent common ancestor, identified by tracing branches backward until they meet, rather than simply looking at tips drawn closest together.

In the sample cladogram from DL4, what traits are successively added among fish, frog, lizard, and bird?

Fish branches first with a backbone; frog adds four limbs; lizard adds an amniotic egg; and bird has a feather trait on its own branch.

How does DNA sequence comparison help determine evolutionary relatedness?

It assesses relatedness by comparing corresponding DNA positions; fewer sequence differences usually support a closer evolutionary relationship for the same gene or region.

What are the major structural differences between prokaryotes and eukaryotes?

Prokaryotes lack a nucleus and membrane-bound organelles and are unicellular with DNA not enclosed in a nucleus. Eukaryotes have a true nucleus, membrane-bound organelles, DNA mainly in the nucleus, and can be unicellular or multicellular.

What distinguishing cell wall characteristic separates the domain Bacteria from Archaea?

Bacterial cell walls typically contain peptidoglycan, whereas Archaea cell walls lack peptidoglycan.

What nutritional modes characterize the six kingdoms in the six-kingdom model?

Eubacteria, Archaebacteria, and Protista can be autotrophs or heterotrophs; Fungi absorb organic nutrients; Plantae mostly use photosynthesis; and Animalia ingest other organisms or food.

What are two key differences between plants and fungi?

Plants generally photosynthesize with chloroplasts and possess cellulose cell walls, whereas fungi lack chloroplasts, absorb nutrients, and have chitin cell walls.

What is a virus and what are its primary structural components?

A virus is an acellular infectious agent that requires a host cell to reproduce, consisting of a genome (DNA or RNA) surrounded by a protein coat called a capsid, and sometimes an additional membrane envelope.

How do the lytic and lysogenic reproductive cycles of viruses differ?

In the lytic cycle, the virus attaches, injects its genome, synthesizes components, assembles, and rapidly releases new virions through host cell lysis. In the lysogenic cycle, the viral genome integrates into host DNA (becoming a provirus) and replicates passively with the host before later switching to lytic replication.

What is a retrovirus and which enzyme does it utilize?

A retrovirus is an RNA virus that uses the enzyme reverse transcriptase to synthesize DNA from an RNA template.

What does the endosymbiotic theory state regarding the origins of mitochondria and chloroplasts?

An ancestral larger cell engulfed smaller prokaryotes that survived and evolved into mitochondria; a photosynthetic engulfed cell later gave rise to chloroplasts in plant and algal ancestors.

What four lines of evidence support the endosymbiotic theory?

Mitochondria and chloroplasts have their own circular DNA, bacterial-like ribosomes, double membranes, and divide independently by fission.

What is the formula used to calculate total microscope magnification?

$$\text{Total magnification} = \text{eyepiece magnification} \times \text{objective magnification}$$

What is the formula for calculating an unknown field of view (FOV)?

$$\text{FOV}_1 \times \text{magnification}_1 = \text{FOV}_2 \times \text{magnification}_2$$

How is the estimated size of an object under a microscope calculated?

$$\text{Approximate object size} = \frac{\text{field-of-view diameter}}{\text{number of objects fitting across the diameter}}$$

What is the metric conversion factor between millimetres and micrometres?

$$1\,\text{mm} = 1000\,\mu\text{m}$$

What are the three main functional categories of protists?

Animal-like protists (heterotrophic protozoans such as Amoeba and Paramecium), plant-like protists (photosynthetic algae), and fungus-like protists (absorptive decomposers such as slime molds or water molds).

What three structures do protists use for locomotion or feeding?

Cilia (many short hair-like projections), flagella (one or more long whip-like structures), and pseudopodia (temporary cell extensions).

From what group did land plants evolve, and what evidence supports this ancestry?

Land plants evolved from green-algal ancestors, especially relatives of charophyte green algae, supported by similar chlorophyll pigments, cellulose cell walls, and genetic similarities.

What are the four major groups of land plants and their evolutionary sequence?

Bryophytes (nonvascular/spores) > Seedless vascular plants (ferns, vascular/spores) > Gymnosperms (naked seeds) > Angiosperms (flowering plants with seeds enclosed in fruits).

What are hyphae and mycelium in fungi?

Hyphae are threadlike fungal filaments, and a mycelium is the interconnected mass formed by these hyphae.

What is a lichen?

A mutualistic association between a fungus and a photosynthetic alga or cyanobacterium.

What are the three types of body symmetry found in animals?

Asymmetry (no predictable plane of symmetry, e.g., sponges), radial symmetry (parts arranged around a central axis, e.g., cnidarians), and bilateral symmetry (one plane divides the body into left and right halves).

What defines a true coelom in animals?

A body cavity that is completely lined by mesoderm.

What are the defining characteristics of phylum Porifera and phylum Cnidaria?

Porifera (sponges) lack true tissues, are often asymmetrical, and are filter feeders; Cnidaria (jellyfish, corals) have radial symmetry and specialized stinging cells called cnidocytes.

What are the key traits of Platyhelminthes, Annelida, and Mollusca?

Platyhelminthes are bilateral, flattened, acoelomate flatworms; Annelida are segmented bilateral worms with a true coelom; Mollusca have soft bodies commonly featuring a mantle and muscular foot.

What are the distinctive traits of phylum Echinodermata?

Adults often exhibit pentaradial symmetry and they possess a water vascular system (e.g., sea stars, urchins).

What are two major identifying characteristics of phylum Arthropoda?

They have jointed appendages and a hard protective exoskeleton made mainly of chitin.

What four features characterize chordates at some stage of development?

A notochord, a dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail.