Exam 1 Principles of Bio II

Population

A group of individuals of the same species that live in an area and interbreed.

Heritable

Traits that can be passed from parents to offspring.

Natural Selection

The process by which organisms that are better adapted to their environment (because of genetically heritable differences) tend to survive and produce more offspring.

Genetic Drift

Random changes in allele frequencies within a population from random chance.

Founder Effect

Small group of individuals establish a new population, usually not genetically representative of the original population. (Genetic Drift)

Bottleneck Effect

Many organisms in a population die due to some large-scale event like an earthquake, survivors aren’t genetically representative (Genetic Drift)

Phylogeny

Evolutionary history of an organism

Taxon

Name given to organisms to classify them.

Taxonomy

A process to create taxons for organisms and classify them.

Branch Point

The point on a Phylogenetic tree where two separate species formed from one common ancestor.

Homology

Similar structures between species coming from a shared common ancestor.

Analogy

Similar structures between species evolving by random chance.

Cladistics

Grouping organisms by their phylogenetic trees.

Paraphyletic Group

Many descendants of a common ancestor from a phylogenetic tree, but not all of them. (Ex. Reptiles)

Monophyletic Group

All descendants of a common ancestor in a phylogenetic tree.

Speciation

The process by which new species are founded.

Ecological Niche

The role an organism plays in the ecosystem.

Prokaryote

A cell not containing a nucleus or membrane bound organelles.

Abiogenesis

A theory about how life was created (beginning without life) involving organic molecules forming from inorganic ones, moving together to make amino acids, then those making a protocell which can replicate.

Protocell

A very simplistic form of a cell containing some proteins/amino acids surrounded by a membrane.

Ribozyme

RNA functioning as an enzyme by speeding up reactions.

Montmorillonite

A special kind of clay that lets polymers form from RNA building blocks and makes membranes from lipids.

Cyanobacteria

Photosynthetic bacteria that could have been the reason the earth is oxidized now.

Obligate Anaerobe

Cannot survive in the presence of oxygen.

Obligate Aerobe

Needs oxygen to survive.

Peptidoglycan

The major component of the cell wall in bacteria, giving them shape. Gram positive cells have a thick layer, while Gram negative cells have a thin layer.

Lipopolysaccharide

Molecule found in Gram Negative bacteria’s cell membrane.

Charophyte

Algae that is the closest living relatives to modern-day plants, and it has sporopollenin.

Desiccation

The process of drying out because of the environment.

Sporopollenin

Resistant polymer in algae that stops plants from drying out.

Meristem

Local part of plants that always divides to let the plant keep growing. They act as stem cells, turning into any kind of cell needed.

Sporophyte

Diploid; makes unicellular spores by meiosis.

Gametophyte

Haploid; makes haploid gametes by mitosis

RNA-World Hypothesis

The idea that early life relied on RNA to store info + act as catalyst.

Biological Species Concept

Defines species as populations whose members make viable (reproducing and surviving) offspring. If they can’t make viable offspring, they’re different species (Ex. horses and mules)

Habitat Isolation

Same species live in different habitats, and over time change. (Speciation, Ex. snakes deciding to live in water instead of land). Can be by choice or not by choice.

Temporal Isolation

Members of a population breed during different seasons by preference, over time creating new species. (Ex. skunks breed in late fall OR early winter.)

Behavioral Isolation

Different courting methods that make Speciation (Ex. some Blue-Footed Booby birds show feet to court, others show wings).

Allopatric

Geographic separation which causes Speciation not by choice (Ex. an earthquake separating populations).

Flagellin

Protein in prokaryotic flagellum. Bacteria move by using their flagellum as a motor.

Tubulin

Protein in eukaryotic flagellum. Eukaryotes move by lashing their flagellum like a whip.