Bio 111 Midterm Vocab

Phylogeny

A branching tree depicting evolutionary relationships among a group of organisms with a common ancestor. Shows ancestor and descendants.

Insects

½ of all species on Earth.

Evolution

Changes in allele frequencies across generations.

Key Mechanisms of Evolution

Mutation, genetic drift, natural selection, sexual selection, and gene flow.

Mendelian study of evolutionary change

The study of how genes in individuals are inherited from parents.

Quantitative study of evolutionary change

Looking at populations and seeing how multiple genes are favored for survival.

Allele Frequencies

Count up the total number of one type of allele and divide by the total number of alleles.

Genetic drift

Within small populations, frequency of existing gene variants changes due to random chance. Causes random changes in allele frequencies.

Sexual Selection

Can be intra-sexual = male-male competition, or inter-sexual = female choice of mate.

Gene flow

Migration or Immigration between populations. That causes allele frequencies to change.

Maladaptation

When a species is not appropriately adjusting to their environment (may be a new environment due to climate change) and can lead to extinction or extirpation.

Ecological Traps

When organisms make poor habitat choices based on cues that correlated formerly with habitat quality.

Evolutionary Traps

Dissociation between cues that organisms use to make any behavioral or life-history decision and outcomes normally associated with that decision.

Range changes

The change in distribution (where a species is located in the world).

Elevational shifts

As species (like birds) get pushed up or down the mountain, their habitat space may run out.

Latitudinal shift

When a species is pushed north or south of its original habitat, this may lead to habitat space running out.

Symbiosis

Interaction between two organisms living in close proximity, typically a mutual advantage however could be a disadvantage or no effect. "Living together". Played a big role in the evolution of life.

Microbiome

Community of microorganisms existing in a particular environment. Most plants and animals have microbes living in and on them.

Microbe

Within the invisible world, about 100 nm to 1 um. Microbes reproduce very quickly due to small surface area. Because they are small cells, they can absorb more nutrients per unit volume, thus needing less energy and nutrients to survive and reproduce.

Plasma Membrane

Boundary of all cells made up of a phospholipid bilayer. This is made up of hydrophobic (fear of water) tails on the inside, which consist of lipids, and a hydrophilic head group (phosphorus) on the inside and outside of the lipids.

Plasmids

Small DNA molecules in bacteria that are picked up from the environment that help them survive adverse conditions or harm the bacteria like a parasite.

DNA polymerase

An enzyme that makes up a replisome, aids in bringing in new nucleotides during replication to complete both single strands of the DNA that was split and creates two double strands of DNA.

Replisome

Consists of DNA polymerase that aids in bringing new nucleotides during replication to complete both single strands of the DNA that was split and creates two double strands of DNA.

Photoautotroph

An organism that makes its own energy using sunlight and carbon dioxide via photosynthesis.

Heterotroph

An organism that cannot produce its own energy, getting carbon from other organic sources like plant or animal matter.

Ribosome

Consists of ribosomal RNA and proteins, where mRNA is translated into proteins.

Special Creation

The belief that a higher power created life on Earth.

Panspermia

Undirected - dispersal of microbes from planet to planet. Directed - deliberate seeding of planets by aliens. Misdirected - galactic pollution by spacecraft (meteors).

Spontaneous generation

The theory that life spontaneously and randomly appeared.

Electron transport chain

Happens in the mitochondria of eukaryotes, when electrons are passed from more electropositive to more electronegative molecules and in the process energy is released.

Glycolysis

Initial stage of energy production where a 6-carbon molecule of glucose is broken down into two 3-carbon molecules of pyruvate.

Fermentation

If oxygen is not available, pyruvate is the final electron acceptor. NADH must be re-oxidized (loss of electron) to NAD+ as the electron carrier necessary for a fresh round of glycolysis. This process doesn’t generate energy.

Phylogenetic Methods

Start with a sequence alignment, identify changes at homologous sites, choose either distance-based approach or parsimony.

Domains

Bacteria, Eukarya, Archaea.

Monophyletic

Sharing a common ancestor that excludes other groups.

Relatedness

When two species share a common ancestor. The more recent that common ancestor is, the more related they are.

LUCA

Last Universal Common Ancestor gave rise to two daughter cells, one was the ancestor of all living Eubacteria, the other was the ancestor to all living Archaea.

Endosymbiotic theory

A horizontal process (Horizontal Gene Transfer) across a phylogenetic tree in which prokaryote engulfed another prokaryote.

Evolutionary Trade-Off

Adapting to one thing will include trade-offs of being less good at something else.

Phage

A virus that infects bacteria or archaea, highly diverse, linear double-stranded DNA.

Features of fungi

Fungi are single-celled or multicellular (made of filaments that are thread-like cells). They have cell walls that are made of chitin. Fungi don't have a complex transport system like animals and plants do with a vascular system, instead, they are made of hyphae. Fungi are heterotrophs, they absorb food directly from surroundings.

Mycelia

Network of hyphae underground that allows the mushroom to absorb nutrients from their surroundings.

Hyphae

Cells that make up Fungi, they are long and thin, creating a large surface area which leads to high absorption.

Fungi Reproduction

They reproduce sexually and asexually, and sometimes during both haploid and diploid phases.

Plasmogamy

Sexual reproduction in fungi when two compatible individuals fuse their mycelia together to initiate the sexual cycle.

Karyogamy

When a dikaryotic cell fuses their two haploid nuclei, creating a cell with a 2n nucleus.

Saprophytes

Fungi are saprophytes meaning they eat dead stuff, decomposers.

Yeast

A single-celled fungus that reproduces by budding and is able to ferment sugars.

Mycorrhizae

Through symbiosis of plant and fungi, mycorrhizae are created.

Monophyletic

A group that evolved from a common ancestor and includes all descendants.

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Secondary Endosymbiosis

The process in which an organism engulfs a cell that has previously undergone endosymbiosis, resulting in the transfer of genetic material and acquisition of a new organelle.

Photosynthesis

The process by which organisms convert sunlight, water, and carbon dioxide into glucose and oxygen, using chlorophyll and other pigments.

Phytoplankton

Single-celled photosynthetic organisms, either bacteria or eukaryotes, that form the base of the ocean food web.

Trophic Cascade

An ecological change that occurs when a predator is removed from the food pyramid, leading to impacts on prey animals and vegetation.

Carotenoid

A pigment used in photosynthesis and found in various organisms for UV protection, coloration, and photosynthetic purposes.

Viridiplantae

A monophyletic group of "green plants" characterized by key innovations such as chloroplasts, UV-absorbing compounds, a cuticle, and specific reproduction methods.

Non Vascular Plants

The first plants to evolve, lacking vascular tissue and relying on diffusion to absorb water and nutrients from their surroundings.

Desiccation Resistant Spores

Spores with a tough outer shell that can resist drying out, survive for long periods, and be dispersed.

Bryophytes

Non-vascular plants, such as mosses, that lack true roots and absorb water and nutrients through their leaves. They undergo alternation of generations, with the gametophyte phase being more dominant.

Cuticle

A watertight sealant covering aboveground plant parts, produced by epidermal cells and composed of hydrocarbons, lipids, and wax. It prevents water loss and limits gas exchange.

Spore

A reproductive product (1n) encased in a tough outer shell, allowing for resistance to drying, long-term survival, and wind dispersal.

Alternation of Generations

A reproductive cycle in plants where multicellular organisms exist in both 1n (gametophyte) and 2n (sporophyte) stages, with spores and gametes being produced.

Gametophyte

A multicellular organism in the 1n stage of the alternation of generations, where cells fuse to form a 2n zygote.

Sporophyte

A multicellular organism in the 2n stage of the alternation of generations, which produces spores through meiosis.

Sphagnum

A type of moss that forms peatlands, acting as a keystone species and creating highly efficient carbon sinks. They have slow growth rates.

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