Science Process & Life Sciences — Vocabulary Flashcards

Vocabulary flashcards covering key terms from science process, experimental design, life forms, cell biology, taxonomy, and emerging topics.

Science

Systematic study of the natural world using observation, hypothesis testing, experimentation, analysis, and communication; yields a cumulative, peer-reviewed body of knowledge.

Traditional scientific method

Linear, checklist-style model of procedure commonly taught in textbooks.

Real scientific process

Iterative, community-driven cycle including exploration, testing ideas, and community analysis & feedback.

Exploration & Discovery

Stage to identify gaps in knowledge through data mining, literature review, and field observations.

Testing Ideas

Phase involving hypothesis formulation, experimental design, and statistical planning.

Community Analysis & Feedback

Peer review, open data sharing, and replication studies to critically evaluate findings.

Benefits & Outcomes

Innovations, evidence-based policy, education, and public engagement arising from scientific work.

Hypothesis

A plausible, testable, and falsifiable explanation grounded in existing knowledge.

Prediction

A concrete, quantitative expectation derived from a hypothesis.

Theory

A broad explanatory framework supported by a body of evidence.

Law

Concise statement of a regularity (often mathematical), e.g., Newton’s law of gravitation.

Tentativeness

All scientific claims are provisional; revisions occur via peer review and replication.

Control

Baseline in an experiment that isolates the effect of the independent variable.

Independent variable

Variable deliberately altered by the researcher.

Dependent variable

Outcome measured; expected to change in response to the independent variable.

Controlled variables

Factors kept constant to prevent confounding effects.

Randomization

Random assignment of subjects to groups to reduce bias.

Blinding

Masking of group assignment to reduce bias (single or double blind).

Placebo

Inert treatment used as a control to test the effect of an intervention.

Statistical power

Probability of detecting a true effect if it exists; depends on sample size and design.

Correlation

Statistical association between variables that may be due to confounders or coincidence; does not imply causation.

Causation

Cause-and-effect relationship established by controlled experiments isolating variables.

Citizen science

Collaborative research where volunteers contribute data, observations, or analyses to professional projects.

iNaturalist

Web platform enabling open participation for biodiversity observations in citizen science.

eBird

Citizen science database of bird observations using standardized protocols.

Protists

Diverse eukaryotic organisms, which can be photosynthetic, heterotrophic, or mixotrophic, representing a paraphyletic group (i.e., not a single evolutionary lineage) including various algae, protozoa, and slime molds.

Chlamydomonas

A genus of green algae, serving as a representative example of a photosynthetic protist.

Amoeba

A type of heterotrophic protist characterized by its irregular, changing shape and movement via temporary cytoplasmic extensions called pseudopods.

Paramecium

A genus of motile ciliate protists, known for their slipper-like shape, locomotion and feeding using cilia, and complex reproductive processes including conjugation.

Seven characteristics of life

Fundamental traits that define living organisms: cellular organization, response to stimuli, reproduction, growth and development, energy processing, homeostasis, and evolutionary adaptation.

Cellular organization

All living systems are composed of one or more cells, the fundamental unit of life, demonstrating a hierarchical organization.

Response to stimuli

Organisms possess the ability to detect and react to changes or cues in their internal or external environment.

Reproduction

The biological process by which new individual organisms (offspring) are produced from their parents, ensuring the continuation of species (can be sexual or asexual).

Growth and development

Living organisms increase in size (growth) and undergo a series of progressive changes over their life cycle, leading to maturation and specialized functions (development).

Energy processing

Organisms acquire and transform energy through metabolic processes (e.g., catabolism, anabolism) to fuel their life functions, such as growth, maintenance, and reproduction.

Homeostasis

The active regulation by an organism to maintain stable, relatively constant internal physical and chemical conditions (e.g., temperature, pH, glucose levels) despite external fluctuations.

Evolutionary adaptation

Populations of organisms acquire heritable traits over generations that enhance their survival and reproductive success in a specific environment, driven by natural selection and genetic drift.

Domain

The highest taxonomic rank in the biological classification of life, categorizing all organisms into three major lineages: Archaea, Bacteria, and Eukarya.

Binomial nomenclature

A formal system of naming species, consisting of two parts: the genus name (capitalized) and the species epithet (lowercase), both italicized (e.g., Homo sapiens).

Dichotomous key

A scientific tool used to identify organisms or objects by presenting a series of paired statements, with each choice leading to another pair of statements until the identification is made.

Fungi

A kingdom of eukaryotic organisms characterized by cell walls containing chitin, typically forming filamentous structures called hyphae which collectively make up a mycelium, performing extracellular digestion, and reproducing via spores.

Chitin

A tough, nitrogen-containing polysaccharide that forms the primary component of fungal cell walls and the exoskeletons of arthropods.

Hyphae

The thread-like, branching filaments that constitute the main body (mycelium) of most fungi, responsible for absorption of nutrients.

Mycelium

The vegetative part of a fungus, consisting of a network of branching filamentous hyphae, typically growing underground or within a substrate.

Fungi ecological roles

Fungi play crucial roles in ecosystems as decomposers (breaking down organic matter), symbionts (e.g., mycorrhizal associations with plants), and pathogens (causing diseases in plants and animals).

Plants

Multicellular, eukaryotic organisms primarily characterized by photosynthesis (using chlorophyll a/b), cell walls made of cellulose, the presence of vascular tissues (xylem and phloem), and often exhibiting diverse reproductive strategies (e.g., seeds, spores, flowers).

Chlorophyll-a/b

The primary photosynthetic pigments found in plants and algae, responsible for absorbing light energy to drive the process of photosynthesis.

Carotenoids

Accessory pigments in plants and some other photosynthetic organisms that absorb light in different wavelengths than chlorophyll, providing additional light capture and photoprotection.

Xylem

A principal vascular tissue in plants responsible for the unidirectional transport of water and dissolved minerals from the roots to the rest of the plant, primarily driven by transpiration.

Phloem

A principal vascular tissue in plants responsible for transporting sugars (produced during photosynthesis) and other organic nutrients from leaves (sources) to other parts of the plant where they are needed for growth or storage (sinks).

Lignin

A complex, rigid polymer that strengthens and waterproofs the secondary cell walls of vascular plants, providing structural support and enabling plants to grow tall.

Cuticle

A protective, waxy, and water-impermeable layer secreted by the epidermal cells on the surface of plant stems and leaves, primarily to reduce water loss.

Stomata

Microscopic pores, typically on the underside of plant leaves, surrounded by guard cells, that regulate gas exchange (carbon dioxide uptake, oxygen release) and water vapor transpiration.

Root systems

The underground network of roots, whose primary functions include anchoring the plant, absorbing water and dissolved mineral nutrients from the soil, and storing food reserves.

Plants reproductive strategies

Diverse methods employed by plants for reproduction, including sexual reproduction involving wind or animal pollination of flowers, and various mechanisms for seed and spore dispersal.

Animals

Multicellular, heterotrophic eukaryotic organisms characterized by their ability to move (locomotion), the absence of cell walls, the presence of various specialized tissues (e.g., nervous, muscular), and typically complex sensory systems to interact with their environment.

Endoskeleton

An internal skeleton, such as bone or cartilage in vertebrates, that provides structural support, protection for internal organs, and points of attachment for muscles, allowing for movement.

Closed circulatory system

A circulatory system where blood is confined within a network of blood vessels (arteries, veins, capillaries) and pumped by a heart, allowing for efficient and regulated transport of substances.

Lungs

Paired respiratory organs found in many terrestrial vertebrates, responsible for gas exchange, where oxygen is absorbed into the bloodstream and carbon dioxide is released.

Amniotic egg

A desiccation-resistant egg, characteristic of reptiles, birds, and monotremes, containing specialized membranes (amnion, chorion, allantois, yolk sac) that protect and nourish the developing embryo on land, reducing dependence on water for reproduction.

Cell Theory

A fundamental biological principle stating that all living organisms are composed of one or more cells, cells are the basic unit of life, and all cells arise from pre-existing cells.

Cell Cycle (G1, S, G2, M)

The ordered sequence of events that a cell undergoes from its formation to its division into two daughter cells. It consists of interphase (G1-growth, S-DNA synthesis, G2-preparation for mitosis) and the mitotic phase (M-mitosis and cytokinesis).

Apoptosis

Programmed cell death, a highly regulated process essential for normal development, tissue homeostasis, and elimination of damaged or unwanted cells.

Stem cells

Undifferentiated biological cells that have the capacity for self-renewal (dividing to produce more stem cells) and differentiation (developing into various specialized cell types).

Ribosomes

Complex molecular machines, composed of ribosomal RNA (rRNA) and proteins, responsible for synthesizing proteins from messenger RNA (mRNA) sequences (translation). In eukaryotes, they are found free in the cytoplasm or bound to the rough endoplasmic reticulum (RER). In prokaryotes, they are free in the cytoplasm.

Ribosomes (70S)

A specific class of ribosomes, approximately 70S (Svedberg units) in size, composed of a 30S small subunit and a 50S large subunit. These ribosomes are characteristic of prokaryotic cells (bacteria and archaea) and are also found in the mitochondria and chloroplasts of eukaryotic cells, supporting the endosymbiotic theory.

Smooth ER

A network of interconnected membranes within the cytoplasm of eukaryotic cells characterized by the absence of ribosomes on its surface. Its functions include the synthesis of lipids (like phospholipids and steroids), carbohydrates, detoxification of drugs and poisons, and the storage and release of calcium ions for cellular signaling.

Rough ER

A network of interconnected membranes within the cytoplasm of eukaryotic cells, studded with ribosomes on its surface. It plays a crucial role in the synthesis, folding, modification, and quality control of proteins destined for secretion, insertion into membranes, or delivery to other organelles; it also contributes to phospholipid synthesis. Proteins are then packaged into transport vesicles.

Golgi Apparatus

A stack of flattened membrane-bound sacs (cisternae) in eukaryotic cells that further modifies, sorts, and packages proteins and lipids synthesized in the endoplasmic reticulum. It adds carbohydrate tags, directs molecules to their final destinations, and forms vesicles for transport within or out of the cell (secretion).

Lysosomes

Membrane-bound organelles containing a variety of hydrolytic enzymes (acid hydrolases) that function at an acidic pH. They are responsible for the degradation of waste materials, cellular debris, worn-out organelles (autophagy), and macromolecules ingested by endocytosis, enabling the cell to recycle basic building blocks.

Mitochondria

Double-membrane-bound organelles, often called the 'powerhouses' of the cell, found in most eukaryotic cells. They are the primary sites of aerobic cellular respiration, where glucose and other organic molecules are oxidized to produce adenosine triphosphate (ATP), the cell's main energy currency. Mitochondria possess their own circular DNA, 70S ribosomes, and reproduce independently, supporting the endosymbiotic theory.

Chloroplasts

Double-membrane-bound organelles primarily found in plant cells and some protists (algae). They are the sites of photosynthesis, the process by which light energy is converted into chemical energy in the form of glucose and oxygen. Chloroplasts contain chlorophyll pigments, their own circular DNA, and 70S ribosomes, consistent with their endosymbiotic origin.

Cytoskeleton

A complex, dynamic network of protein filaments and tubules (microtubules, actin filaments, intermediate filaments) located in the cytoplasm of eukaryotic cells. It provides structural integrity, maintains cell shape, anchors organelles, enables cell motility (e.g., amoeboid movement, flagella/cilia beating), and facilitates intracellular transport of vesicles and organelles.

Nuclear pore complexes

Large, intricate protein channels embedded in the nuclear envelope of eukaryotic cells. They regulate the selective passage of macromolecules, such as proteins and RNA, between the nucleus and the cytoplasm, playing a vital role in gene expression and cellular regulation.

Total magnification

Product of objective power and ocular power in microscopy.

Resolution (Rayleigh criterion)

Minimum distinguishable distance between two points; ~0.25 \mu m with visible light; <1 nm with electron microscopy.

Gram stain

Bacterial staining method classifying bacteria as Gram-positive or Gram-negative.

Acid-fast stain

Stain for organisms with waxy cell walls (e.g., Mycobacteria).

DAPI

Fluorescent stain that binds DNA for fluorescence microscopy.

Immunofluorescence

Technique using fluorescent antibodies to visualize specific proteins.

Diffusion

Movement of particles from high to low concentration; affected by temperature, gradient, permeability, and surface area.

Osmosis

Diffusion of water across a selectively permeable membrane.

van ’t Hoff equation

\Pi = iCRT; relates osmotic pressure to solute concentration and temperature.

Plasmolysis

Contraction of plant cell membranes in hypertonic solutions.

Turgor pressure

Pressure of cell contents against the cell wall in hypotonic environments.

Systems biology

Integrating genomics, proteomics, and metabolomics to model complex networks.

Synthetic biology

Engineering biology to design new biological parts, devices, and systems (e.g., CRISPR-based gene drives).

Microbiome

Community of microorganisms in a given environment and their collective roles.

CRISPR-based gene drives

Gene-drive systems using CRISPR to bias inheritance and spread traits through populations.

Hypertonic

A solution with a higher concentration of solutes compared to another solution, causing water to move out of cells.

Hypotonic

Solution with lower solute concentration than another solution.

Eu

A Greek prefix meaning 'true,' 'good,' or 'well,' often used in biological terms such as 'eukaryote' (true nucleus).

Karyon

A Greek word meaning 'kernel' or 'nucleus,' used in biological terms like 'eukaryote' (true nucleus) and 'prokaryote' (before nucleus).

Linear DNA

DNA that exists in a straight, elongated form as opposed to circular. It is characteristic of eukaryotic chromosomes.

Pro

A Greek prefix meaning 'before' or 'prior to,' often used in biological terms such as 'prokaryote' (before nucleus).

Bacteria

A domain of life consisting of diverse single-celled, prokaryotic microorganisms. They lack a membrane-bound nucleus and organelles, can exist as independent organisms or as parasites, and play critical roles in various ecosystems.

Archaea

A domain of single-celled prokaryotic microorganisms that, while similar to bacteria in cellular structure, possess distinct genetic and biochemical differences (e.g., in cell wall composition, membrane lipids). They are often found in extreme environments.

Circular DNA

A type of DNA molecule that forms a closed loop, commonly found as the main chromosome in prokaryotes (bacteria and archaea), as well as in plasmids and in the mitochondria and chloroplasts of eukaryotes, enabling independent replication.

Unicellular

Describing an organism that consists of only a single cell, which is capable of performing all necessary life functions independently.

Phospholipid

A class of lipids that are a major component of all cell membranes, consisting of a hydrophilic ('water-loving') polar head (containing a phosphate group) and two hydrophobic ('water-fearing') nonpolar fatty acid tails. This amphipathic nature is crucial for forming the lipid bilayer.