Chapter 1: Principles of Life

Organism

All living things; An individual living entity that grows and reproduces as an independent unit.

Nucleic acids

Molecules that could reproduce themselves and also contain the information for the synthesis, or manufacture, of other large molecules with complex (but stable) shapes [proteins]

Protein

Large, complex molecules synthesized by nucleic acids which are able to interact and react with other molecules.

Cell membrane - evolution

Evolved after nucleic acids; Enabled the formation of fatty acid layer that separated cells from the surrounding environment.

Prokaryotes

Unicellular organisms that do not have nuclei. Includes bacteria and prokaryotic archaeans.

Biology

The scientific study of living things or organisms.

Photosynthesis

A set of chemical reactions that transforms the energy of sunlight into chemical-bond energy of the sugar glucose and other relatively small biological molecules; Evolved around 2.5 billion years ago.

Aerobic metabolism (cellular respiration)

Requires or uses oxygen; Releases energy from life's molecules by using O2.

Anaerobic metabolism

a set of reactions that extracts energy without using O2.

Ozone (O3)

A result of O2 accumulation in the atmosphere, which then created a layer of ozone to protect living organisms on land on Earth.

Organelles

Structures specialized to perform distinct processes within a cell -> little organs

Cyanobacteria

Similar to early photosynthetic prokaryotic cells; Aquatic and photosynthetic.

Nucleus

A part of the cell containing DNA and RNA and responsible for growth and reproduction

Eukaryote

Organisms made up of one or more complex cells, including a nucleus.

Three Domains of Life

Bacteria, Archaea, and Eukarya.

Endosymbiosis

The engulfing of one cell by another; Thought to be the precursor to eukaryotic cells.

Mitochondria

Organelle within eukaryotic cells that release energy for use; Thought to evolve from engulfed prokaryotic organisms.

Chloroplast

Organelle found in cells of plants and some other organisms; Conduct photosynthesis in photosynthetic eukaryotes.

Cellular specialization

The division of labor in multicellular organisms, where different cells types become responsible for different functions within the host organism; Enabled multicellular eukaryotes to increase in size and become more efficient at gathering resources.

Genome

The sum total of its genetic material; The complete DNA (or RNA for viruses) sequence for a particular organism or individual.

Mutation

A change in the genetic material that is not caused by recombination; Alter nucleotide sequences of a gene and protein.

Binomial

A name system which each species is given two names; [Genus species]

Phylogenic tree

A "tree" that documents and diagrams evolutionary relationships as part of an overarching "tree of life"

Eukarya

Arose from the Archaea; Defining contributions of mitochondria and chloroplasts from endosymbiotic bacteria.

Tree of Life

A term that encompasses the evolutionary history of all life, or a graphic representation of that history.

Bacteria

One of the major branches of life; Unicellular organisms lacking a nucleus, can process distinctive ribosomes and tRNA. Distinguished primarily by nucleotide sequence data.

Archaea

One of the major branches of life; Main line of specialized groups of organisms (eukaryotes)

Model system / Model organisms

Small groups of organisms that adapt well to laboratory situations and are able to be applied across a broad range of species.

Nucleotides

Basic units of DNA molecule, composed of a sugar, a phosphate, and one of 4 DNA bases (adenosine, guanine, cytosine, and thymine)

Gene

A unit of heredity; Specific segment of DNA whose sequence carries the information for building one or more proteins.

Proteins

Molecules that govern the chemical reactions within cells and form much of an organism's structure; Genes "encode" proteins.

Natural history of organisms

The understanding of how an organism survives in the world, as well as its behaviors, reproduction, and interactions with other organisms.

Quantitative

numbers

Qualittative

no numbers / descriptions.

Controlled experiment

An experiment in which only one variable is manipulated at a time.

Comparative experiment

Compares unmanipulated data gathered from different sources

Null hypothesis

the hypothesis that there is no significant difference between specified populations, any observed difference being due to sampling or experimental error.