189 - Ch 1 Levels of Organisation

Vocabulary-style flashcards covering key terms, concepts, and processes from Chapter 1: Invitation to Biology.

Animals

Multicellular eukaryotic consumers made of unwalled cells that develop through stages, ingest food, usually reproduce sexually, and can move.

Archaea

Domain of prokaryotes more closely related to eukaryotes than to bacteria.

Atom

Smallest unit of matter, composed of protons, neutrons, and electrons.

Bacteria

Largest, most diverse domain of prokaryotes that diverged early from archaea and eukaryotes.

Biology

Scientific study of life.

Biosphere

All regions of Earth where organisms live.

Cell

Smallest unit of life; begins with plasma membrane, cytosol, and DNA.

Community

All populations of all species living in a defined area.

Consumer

Heterotroph that obtains carbon and energy by feeding on other organisms or their remains.

Control group

Experimental group identical to the test group except for the variable under investigation.

Critical thinking

Evaluating information before accepting it.

Data

Factual information collected from experiments or observations.

Development

Process by which the first cell of a new individual becomes an adult in multicelled species.

DNA

Deoxyribonucleic acid; double-stranded nucleic acid carrying hereditary information.

Ecosystem

Community interacting with its environment.

Eukaryotes

Organisms whose cells possess a nucleus (protists, fungi, plants, animals).

Experiment

Procedure designed to test a prediction and yield data.

Experimental group

Individuals receiving the variable or treatment being tested, compared to a control group.

Fungi

Single-celled or multicelled eukaryotic consumers that digest externally and absorb nutrients.

Genus

Taxonomic group of closely related species; first part of a species’ scientific name.

Growth

Increase in cell number, size, or volume.

Homeostasis

Maintenance of internal conditions within tolerable ranges by sensing and responding to change.

Hypothesis

Testable explanation for a natural phenomenon.

Inheritance

Transmission of DNA to offspring.

Law of nature

Generalization describing a consistent natural phenomenon lacking complete explanation.

Model

Analogous system used in experiments in place of another subject.

Molecule

Two or more atoms joined by chemical bonds.

Nutrient

Substance an organism must obtain from the environment for growth and survival.

Organ

Structural unit of two or more tissues arranged to perform a specific task.

Organism

Individual living entity consisting of one or more cells.

Organ system

Set of interacting organs performing a collective function.

Photosynthesis

Metabolic pathway where autotrophs use light energy to build sugars from CO₂ and water.

Plants

Multicellular, typically photosynthetic eukaryotes that develop from nourished embryos within the parent plant.

Population

Group of individuals of the same species in a given area that interbreed more with each other than with outsiders.

Prediction

Logical statement about an outcome if a hypothesis is correct.

Probability

Chance that a particular outcome will occur out of all possible outcomes.

Producer

Autotroph that makes its own food from energy and raw materials in the environment.

Prokaryotes

Informal term for single-celled organisms without a nucleus (bacteria and archaea).

Protista

General term for eukaryotes that are not fungi, plants, or animals.

Pseudoscience

Claims or methods presented as science but lacking adherence to scientific principles.

Reproduction

Processes by which organisms produce offspring (sexual or asexual).

Sampling error

Difference between results from a subset and those from the whole population.

Science

Systematic study of the observable world.

Scientific method

Process of making hypotheses, testing predictions, and forming conclusions from data.

Scientific theory

Hypothesis that has withstood extensive testing, fits existing evidence, and predicts a wide range of phenomena.

Species

Unique type of organism whose members can potentially interbreed and produce fertile offspring.

Statistically significant

Result very unlikely to have occurred by chance alone.

Taxon

Rank in biological classification grouping organisms with shared traits (e.g., genus, family).

Taxonomy

Practice of naming, describing, and classifying species.

Tissue

Group of specialized cells organized to perform collective functions.

Traits

Inherited characteristics of an organism or species.

Variable

Characteristic or event that differs among individuals or over time in an experiment.

Levels of organization

Hierarchy from atom → molecule → cell → tissue → organ → organ system → organism → population → community → ecosystem → biosphere.

Properties of life

Cellular basis

need for energy/nutrients homeostasis

DNA-based inheritance.

Energy flow

One-way movement of energy from the sun to producers to consumers, eventually lost as heat.

Characteristic of life

consist of 1 or more cells

require energy

sense/respond

homeostasis

growth and reproduction

Purpose of DNA

Stores hereditary information and encodes instructions for building proteins that guide development and regulation.

Producers vs. Consumers

Producers make food from non-biological materials; consumers obtain food by eating producers or other consumers.

Domains of life

Three major lineages—Bacteria, Archaea, and Eukarya—based on cellular structure and genetics.

Archaea–Eukaryote relationship

Genetic evidence shows archaea are more closely related to eukaryotes than to bacteria.

Prokaryotic cell

Single-celled organism lacking membrane-bound organelles, including a nucleus.

Eukaryotic cell

Cell containing membrane-bound organelles, such as a nucleus, and may be unicellular or multicellular.

Linnaean system

Binomial naming system (genus + specific epithet) forming the basis of modern taxonomy.

how to reduce Sampling error

Increase sample size and use random sampling to minimize discrepancy between sample and population results.

Avoiding bias

Declare conflicts of interest and rely on quantitative, objective measurements.

four main groups of euk

protistas

animalia

plantae

fungi

components of scientific name

species - based on evolutionary relationships

genus - grouping of related species

postive control vs negative

positive - receives treatment with known result

negative - receives no treatment