Process of Science / Properties & Chemistry — Life on Mars (Lecture Notes)

Vocabulary flashcards covering key concepts from the lecture notes on the process of science, life concepts, and basic biology.

Independent Variable

The variable deliberately changed in an experiment to test its effect.

Dependent Variable

The variable measured to assess the effect of the independent variable.

Control Group

Group that experiences no experimental intervention; baseline for comparison.

Experimental Group

Group that receives the experimental intervention or manipulation.

Placebo

A fake treatment that mimics the experience of the experimental groups.

Randomized Controlled Trial

An experimental design with random assignment to groups to minimize bias.

p-value

Probability that results are due to chance; commonly compared to 0.05.

Statistical Significance

A result unlikely to occur by chance, typically with p < 0.05.

Correlation

A statistical relationship between two variables; does not prove causation.

Causation

A cause-and-effect relationship supported by evidence.

Peer Review

System of checks in which other scientists evaluate research before publication.

MMR Vaccine

Measles, Mumps, and Rubella vaccine.

MMR-Autism Controversy

Early report alleging a link between MMR vaccine and autism; later shown flawed and unsupported.

Semmelweis

Physician who reduced childbed fever mortality by mandating hand washing with antiseptics.

Hand Washing with Antiseptics

Practice of washing hands with antiseptic solutions to prevent infection.

van Leeuwenhoek

17th-century inventor of simple, powerful microscopes enabling observation of tiny organisms.

Microscope

Instrument that magnifies small objects; relies on lenses and illumination.

Lens

Part of a microscope that magnifies; van Leeuwenhoek’s lenses were notably effective.

Culture of Science

Scientific culture characterized by replication, skepticism, cooperation, and competition.

Skeptic vs Cynic

Scientists are skeptics who test claims; cynics doubt without testing.

Virus

Non-cellular infectious agent; carries genetic material and protein coat; often not considered alive.

Virus Structure

Nucleic acid genome enclosed by a protein coat (capsid).

Life is Cellular

All living things are composed of cells; organized into cells, tissues, organs, and organ systems.

Domains of Life

Three domains: Bacteria, Archaea, and Eukarya; Archaea are prokaryotes closely related to Eukarya.

Cell Theory

All living things are made of cells; cells are the basic units of life.

Autotroph / Producer

Organisms that produce their own energy, typically via photosynthesis or chemosynthesis.

Heterotroph / Consumer

Organisms that obtain energy by consuming other organisms.

Metabolism

Sum of all chemical reactions in living things; includes breaking down and building up mass.

Energy Processing

Process by which organisms obtain and use energy from sunlight or food.

Photosynthesis

Process by which autotrophs convert light energy into chemical energy.

Chemosynthesis

Energy derived from chemical reactions rather than light, used by some autotrophs.

Evolution

Descent with modification; species related through common ancestry and accumulate differences over generations.

Descent with Modification

Darwin’s phrase for evolution; new species arise from common ancestors with changes.

Four Classes of Life Molecules

Carbohydrates, lipids, proteins, and nucleic acids constitute the fundamental molecules of life.

Organic vs Inorganic

Organic molecules contain carbon; many life molecules are organic; inorganic lack carbon or have different bonds.

Water and Polarity

Water is a polar molecule; its polarity makes it an excellent solvent for charged or polar substances.

Hydrogen Bond

A weak attraction between a hydrogen atom and an electronegative atom, influencing water’s properties.

Acids and Bases

Acids donate protons (H+); bases accept protons, affecting pH.

Subatomic Particles

Protons, neutrons, and electrons that compose atoms.

Isotopes

Variants of elements with different numbers of neutrons.

Cell Membrane

Phospholipid bilayer that surrounds the cell and regulates what enters and leaves.

Growth

Growth is an increase in size; unicellular growth means cell enlargement; multicellular growth means more cells.

Reproduction

Process of producing new organisms; offspring resemble but are not necessarily identical.

Adaptation

Evolutionary changes that improve an organism’s survival and reproduction.