Biol unit and exam 3

what are the criteria for coevolution to occur?

1. two or more interacting species must exist in the same place at the same time

2. each species must exert a direct selection pressure affecting the others’ survival and reproduction

Criteria for evolution by natural selection to occur:

1. variation must exist among organisms in a population

2. the varying trait must be heritabloe

3. differential survival and reproduction must occur

4. individuals with traits best suited to the environment possess higher fitness and leave more offspring

Examples of coevolution:

Predator-prey dynamics

parasite-host interactions

plant-herbivor / granivore, or pollinator relationships

Coevolutionary Arms race?

a continous cycle of reciprocal adaptation where two species evolve new adaptations and counter-adaptation in response to eachother

an example of a coevolutionary arms race and why its a coevolutionary arms race ex

Rough-skinned newts produce powerful neurotoxins (tetrodotoxin) when threatened, while garter snakes have evolved physiological resistance.

restistant snakes survive better and eat toxic newts, which in turn selects for even higher toxicity in newts

What is an example of mutualistic coevolution

Plant-pollinator interacftions

where pollinators obtain nutritional rewards (nectar) while brushing against the plants pollen (reproduction area) and transferring pollen to other plants, ensuring mutual survival and reproduction success

Proboscis Length and Flower Depth Correlation

Coevolving long-tounged flies and flowers (zaluzianskya microsiphon) show a direct positive correlation; deeper flowers require longer probscises, forcing the insect to get clsoe to the pollen source to ensure effective pollination.

Anderson and Johnson study components: interaction frequency

because the zaluziaskya microsiphone provides the bulk of nectar for long-tounged flies, it ensures frequent interaction between the species’. adding the fact that they also rely on eachother for survival and reporudction

Anderson and Johnson study components: Allometry

Measured fly thorax width and flower diameter to account for body scaling size effects

Anderson and Johnson study components: abiotic factors

The authors measure latitude,longitude, and latitude to account for environmental influences on crolla and proboscis length.

Anderson and Johnson study components: Geographic structuring

the authors tested whether trait lengths are geographically structured to rule out gene flow as the cause of trait matching

Anderson and Johnson study components: Seed set assesment

it was used to show whether seed set in plants with short corollas and in plants with long corollas pollination was affected by the fly proboscis length; that flies with longer proboscises successfully pollinate flowers with long corollas but not flowers with short corollas

Anderson & Johnson Study Components: Population-level coevolution

indicated by a positive correlation between fly proboscis length and flower depth, where proboscis length was the only significant factor affecting corolla length

Anderson & Johnson Study Components: did the authors measure the all fitness consequences?

No, because they didn’t measure the survival or reproduction

Anderson & Johnson Study Components:if flies got equal nectar from other species, what would happen to the coevolutionary evidence?

it fail to show, because the flie wouldn’t rely soely on the flower, which means there wouldn’t be enough frequent interaction between them for them to become dependent on one another for survival and reproduction

General characteristics of prokaryotes

they are single-celled organisms

that lack a membrane bound nucleus and organelles

and reproduce via asexual reproduction (binary fission)

Bacteria vs. Archaea Differences: cell wall of bacteria

contains peptidoglycan

Bacteria vs. Archaea Differences: cell wall of archaea

contains pseudopeptidoglucan

Bacteria vs. Archaea Differences: cell membrane of bacteria

standar lipid bilayer

Bacteria vs. Archaea Differences: cell membrane of archaea

can use lipid bilayers or rigid lipid monolayers

Bacteria vs. Archauea differences: Genetics of bacteria, do they lack or have introns?

they lack introns associated with DNA

Bacteria vs. Archauea differences: Genetics of bacteria pt 2

they lack histones associated with DNA

Bacteria vs. Archauea differences: Genetics of Archaea

they have both introns and histones which are associcated with dna

Bacteria vs. Archauea differences: Envrinment and pathogenicity; bacteria

they are common everywhere (non-extremophiles), pathogeneic, and sensitive to antibiotics

Bacteria vs. Archauea differences: Envrinment and pathogenicity; archaea

often extremophiles (high heat and salt) and non pathogenic (insesitive to antibiotics)

what is the importance of the prokaryotes under the category of extremophiles?

they thrive in extreme heat, high salt, high pressure, and cold temps

what is the importance of the prokaryotes under the category of Endospores?

they are tough, dormant structures formed under stress that resist extreme temperatures, UV radiation, and antibitics.

what is the importance of the prokaryotes under the category of abundance and diversity?

They represent the most diverse taxon, living extensively, including in and on other organisms

what is the importance of the prokaryotes under the category of biofilms?

They’re dense bacterial colonies encased in a polysaccharide-rich matrix that shields them from antibiotics

what is the importance of the prokaryotes under the category of bioremediation?

Natural breakdown of environmental pollutants like petroleum hydrocarbons (oild spills) and heavy metals (mercury).

Prokaryotic Metabolic Classification (Energy Sources): what is the term for the energy source sunlight?

phototrops / photo at beginning of the sentence

Prokaryotic Metabolic Classification (Energy Sources): chemical compounds?

Chemotrophs or chemo at beginning of sentence

Prokaryotic Metabolic Classification (Carbon Sources): inorganic CO₂

Autotrophs or Auto

Prokaryotic Metabolic Classification (Carbon Sources): pre-formed organic compounds

Heterotrophs or hetero

Key combinations: Sunlight + CO₂ (e.g. plants)

Photoautotrophs

Key combinations: Chemical energy + organic carbon (e.g. animals, fungi, and many bacteria)

Chemoheterotrophs

Key combinations: Sunlight + organic carbon

Photoheterotrophs

Key combinations: inorganic chemical energy + CO₂ (e.g. deep-sea vent microbes)

Chemoautotrophs

what are the eukaryotic characteristics?

They posess membrane-bound nucleus with linear DNA

membrane-bound organelles (mitochondria, chloroplasts)

and undergo mitosis and meiosis

What is the endosymbiotic theory?

organelles evolved when a larger acestral host cell engulfed smaller prokaryotic cells without digesting them, forming a permanent mutualism

Mitochondria origin?

Evolved from an engulfed aerobic heterotrophic alphaproteobacterium, providing efficient oxygen-baserd energy generation (ATP)

Chloroplast origin?

Evolved from an engulfed photosynthetic cyanobacterium captured by an early eukaryotic lineage

Protist Group Classifications:Plant-like autotrophs performing photosynthesis (green, red, brown)

Algae group

Protist Group Classifications: Animal-like heterotrophs consuming other organisms (amoebas, ciliates)

Protozoa group

Protist group classifications: absorptive decomposers or pathogens (slime molds, water molds/oomycetes)

Fungus like protist group

Key protist lineages: (parasitic with complex life cycles, e.g. plasmodium)

apicomplexans; a single-celled protozoan parasite belonging to the large phylum Apicomplexa

Key Protists lineages: (marine/aquatic with cellulose plates)

Dinoflagellates

Protist support

Flexible plasma membranes, stiff cellulose plates forming the theca (dinoflagellates), mineralized shells/tests (formaniferans), and resting cysts/ endospores.

Protist Feeding

Autotrophic, heterotrophic (phagocytosis/filter-feeding), or mixotrophic

Protist movement

flagella (long whip-like tails), cilia (short hair-like structures), and pseudopodia (temporary cytomplasmic foot extensions).

what is the importance of protists?

1. they form the base of aquatic food webs (phytoplankton)

2. drive global carbon cycling nd oxygen production

3. cause human diseases like malaria (plasmodium), and harmful algal blooms (HABs)

4. provide commercial uses (agar, carrageenan, alginates)

Dinoflagellates anatomy

two perpendigular flagella in a longitudinal groove and transverse girdle groove creating a spinning motion; armored by a cellulose theca and a permenantly condensed nucleus (dinokaryon)

Dinoflagellates and their ecological impact: food webs and health

Vital primary producers, but under warm, nutrient-rich conditions cause harmful algal blooms (“Red Tides”) that accumulate toxins in filter-feeding shellfish and poison humans.

Dinoflagellates and their ecological impact: Coral symbiosis (zoozanthellae)

Photosynthetic dinoflagellates live endosymbiotically inside coral tissues, tradigng sugars for shelter and nutrients.

When does cloral bleacking occur?

when stres (warm water, pollution) causes corals to expel zooxanthellae, leading to starvation and reef collapse

Dinoflagellates and their ecological impact: Bioluminescense

chemical reactions inside scintillons where luciferase acts on luciferen, triggered mechanical shear stress (waves or predators) to create an anti-predator “burglar alarm”

Importance of fungi: what do they help with on earth?

they are the primary decomposers, breaking down dead organic material and recycling nutrielnts

Importance of fungi: what does them being ecological symbionts mean?

that they have essential partnerships with plants (mycorrhizae) and photosynthetic organisms (lichens)

fungi economic and food value

used as food (mushrooms, truffles) and in biotechnology/industry for baking (yeast), brewing, and producing antibiotics (penicillin)

Fungi pathogens

Major agrucultural pests (rusts and smuts) and causes of human/ wildlife diseases (athlete’s foot, chytrid fungus)

the charactistic of fungi that is described as Eukaryotic and heterotrophic

says they acquire nutrients by external absorption (secreting digestive enzymes outside the body)

the charactistic of fungi that they have: chitin cell walls

they’re rigid cell walls reinforced with chitin instead of plant cellulose

body structure of fungi

can be single-celled (yeasts) or multicellular networks of tiny branching filaments called hypae, which weave together into an underground feeding mass called a mycelium

Reproduction of fungi

they reproduce via spores, and both sexually and asexually

key fungal lineages: Microsporidia

extremely reduced, obligate intracellular parasites infecting animals using a unique polar tube

Key Fungal Lineages: chytrids (chytridiomycota)

mostly aquatic fungi with flagellated spores (zoospores); implicated in global amphibian declines

Key Fungal Lineages: zygomycetes

form resistant thick-walled sexual zygosporangia (e.g. black break mold Rhizopus)

Key Fungal Lineages: glomeromycetes

form vital endomycorrhizae (arbuscular mycorrhizae) intimately associated with plant roots

Key Fungal Lineages: Ascomycetes (sac fungi)

characterized by sac-like structures called asci producing ascospores (yeasts, truffles, cup fungi, Penicillium)

Key Fungal Lineages: Basidiomycetes

Recognized by club-shaped spore-bearing structures called basidia (mushrooms, puffballs, shelf fungi, rusts, smuts)

Symbiotic Mutualistic Relationships: Mycorrhizae

Mutualism between fungi and plant roots. Fungal hyphae increase surface area for water and mineral absorption (phosphorus) in exchange for plant photosynthetic sugars.

Symbiotic Mutualistic Relationships: Mycorrhizae; extomycorrhizae (EMF)

Hyphae form a dense sheath/mantle around the root and extend outward into soil and inward between cortical cells without penetrating cell walls.

Symbiotic Mutualistic Relationships: Mycorrhizae; Arbuscular Mycorrhizae (AMF)

Hyphae extend outward into soil and inward, penetrating root cell walls to contact the plasma membrane directly

Lichens: Mutualism between a fungus (Ascomycete/Basidiomycete) and a photobiont (green algae or cyanobacteria).

The fungus provides structure, moisture retention, and protection against herbivores; algae/cyanobacteria provide sugars and nitrogen.

Endophytes:

Fungi living inside plant tissues (e.g., grasses) without causing disease.

Provide host plants with increased drought tolerance or herbivore-deterring alkaloids in exchange for sugars.

Endophytes: Vertical Transmission (asexual)

ungus grows into plant seeds $\rightarrow$ Mutualistic (both plant and fungus must survive).

Endophytes; Horizontal Transmission (Sexual):

Fungus forms a stroma around the plant stem → Parasitic (causes choking disease, suppressing the plant's flower/inflorescence development).

Fungus-Animal Mutualisms: Ruminants/Moose

Fungi live inside animal guts, helping break down complex cellulose

Fungus-Animal Mutualisms: leaf-cutter ants

Ants harvest plant leaves and “farm” fungi, feeding on specialized nutrient rich hyphal structures produced by the fungus

Batrachochytrium dendrobatidis (Bd) Infection in Amphibians: Pathogen & Disease:

Causes chytridiomycosis, threatening global amphibian populations

Batrachochytrium dendrobatidis (Bd) Infection in Amphibians: Temp and climate

thrives in cooler, moist environments and high-altitude habitats

Batrachochytrium dendrobatidis (Bd) Infection in Amphibians: host species and taxonomy

Susceptibility varies drastically between taxonomic groups (e.g., high infection loads in many anurans vs. certain salamanders).

Batrachochytrium dendrobatidis (Bd) Infection in Amphibians: Life stage and age

Juveniles and subadults show higher vulnerability and prevalence compared to tadpoles or adults, largely due to structural skin changes and keratin concentration occurring during metamorphosis.

Batrachochytrium dendrobatidis (Bd) Infection in Amphibians: Environmental Microclimates

Local water chemistry, wetland structure, and geography influence spore transmission and environmental persistence.