National Gifted Olympiad - Biology Level 1 Vocabulary Flashcards

Vocabulary flashcards generated from the National Gifted Olympiad Biology Level 1 scientific training program material.

Prokaryotic Cells

Cells whose genetic material is free in the cytoplasm and not surrounded by a nuclear membrane, such as in bacteria.

Eukaryotic Cells

Cells whose genetic material is enclosed within a true nucleus surrounded by a nuclear membrane, such as in plants, animals, fungi, and protists.

Protoplasm

The living contents enclosed within the plasma membrane, consisting of the cytoplasm and the nucleus.

Cytoskeleton

A network of protein filaments that supports the cell, gives it its shape, anchors organelles inside the cell, and regulates the movement of organelles.

Cell Wall

A perforated membrane that allows materials to pass into and out of the cell, providing support and protection; found in plants, fungi, and bacteria, but absent in animal cells.

Cell Membrane

A double layer composed of phospholipids, proteins, and carbohydrates that defines the cell boundary and regulates the passage of substances through selective permeability.

Golgi Apparatus

An organelle system composed of stacked membranes that modifies, sorts, and packages materials into vesicles, and forms lysosomes.

Lysosome

An organelle originating from Golgi bodies and the endoplasmic reticulum that carries out intracellular digestion and programmed cell death.

Mitochondria

The double-membraned powerhouse of the cell that contains its own genetic material and serves as the site for cellular respiration and ATP generation.

Chloroplast

A double-membraned organelle containing chlorophyll and genetic material that converts light energy into chemical energy through photosynthesis.

Osmosis

The movement of solvent molecules (water) from a solution with a lower solute concentration to a solution with a higher solute concentration across a semipermeable membrane.

Hypertonic Solution

A solution with a higher solute concentration relative to the inside of a cell, causing water to leave the cell and leading to cell shrinkage.

Hypotonic Solution

A solution with a lower solute concentration relative to the inside of a cell, causing water to enter the cell and leading to cell swelling or bursting.

Isotonic Solution

A solution with an equal solute concentration compared to the inside of a cell, resulting in no net movement of water.

Facilitated Diffusion

The passive movement of molecules along their concentration gradient across a cell membrane with the assistance of specific transport or carrier proteins.

Active Transport

The movement of substances across a cell membrane against their concentration gradient (from low to high concentration), requiring energy expenditure.

Phagocytosis

A form of endocytosis (cell eating) in which the cell engulfs solid particles by folding its plasma membrane inward to form an internal vesicle.

Pinocytosis

A form of endocytosis (cell drinking) in which the plasma membrane folds inward to ingest extracellular fluid droplets into vesicles.

Exocytosis

The process of expelling substances outside the cell by fusing intracellular vesicles or vacuoles with the plasma membrane.

Monosaccharides

Single sugar carbohydrate molecules with the chemical formula $C_6H_{12}O_6$ (such as glucose and fructose) that dissolve in water and pass through cell membranes.

Disaccharides

Carbohydrate molecules formed by joining two monosaccharides through the removal of a water molecule ($C_{12}H_{22}O_{11}$), such as sucrose and lactose.

Polysaccharides

Complex carbohydrates composed of many monosaccharide units ($(C_6H_{10}O_5)_n$), such as glycogen, starch, and cellulose, which do not dissolve in water or pass through membranes.

Saturated Fats

Lipids containing single bonds between carbon atoms that are solid at room temperature, such as animal fats.

Unsaturated Fats

Lipids containing one or more double bonds between carbon atoms that are liquid at room temperature, such as vegetable oils.

Enzymes

Special catalytic proteins that lower the activation energy required for biochemical reactions and accelerate reaction rates without being consumed.

Nucleotide

The basic structural unit of nucleic acids, consisting of a pentose sugar, a nitrogenous base, and a phosphate group.

Metabolism

The sum total of all biochemical processes and chemical reactions occurring within the body of a living organism.

Catabolism

Metabolic pathways that break down complex molecules into simpler ones, releasing energy, such as digestion and cellular respiration.

Anabolism

Metabolic pathways that construct complex molecules from simpler ones, consuming energy, such as photosynthesis.

Adenosine Triphosphate (ATP)

The primary cellular energy currency composed of adenine, ribose sugar, and three phosphate groups, storing chemical energy in its phosphate bonds.

Thylakoids

Stacks of flattened membrane sacs inside chloroplasts that contain photosynthetic pigments and serve as the site for light-dependent reactions.

Stroma

The fluid-filled space surrounding grana within a chloroplast where light-independent reactions (Calvin Cycle) take place.

Glycolysis

The breakdown of glucose in the cytoplasm that yields two molecules of pyruvic acid, two NADH molecules, and a net of two ATP.

Krebs Cycle

A series of cyclic oxidation reactions occurring in the mitochondrial matrix that processes acetyl-CoA to produce $CO_2$, ATP, FADH_2, and NADH.

Electron Transport Chain

The final stage of aerobic respiration located in the inner mitochondrial membrane that uses high-energy electrons from NADH and FADH_2 to generate the majority of ATP.

Lactic Acid Fermentation

An anaerobic pathway occurring in muscle cells during oxygen deficiency where pyruvate is converted into lactic acid, yielding two ATP without producing $CO_2$.

Alcoholic Fermentation

An anaerobic pathway occurring in yeast and certain bacteria that converts pyruvate into ethanol, two ATP, and two $CO_2$.

Cell Cycle

The complete sequence of events and time interval between two successive cell divisions, including interphase, mitosis, and cytokinesis.

Interphase

The phase of the cell cycle during which the cell grows ($G_1$), replicates its DNA (S phase), and synthesizes proteins ($G_2$) in preparation for cell division.

Mitosis

Equational cell division occurring in somatic cells ($2n$) that separates duplicated chromosomes to produce two genetically identical diploid daughter cells.

Cytokinesis

The final stage of cell division involving the cleavage or division of the cytoplasm to separate one cell into two distinct daughter cells.

Cyclins

Regulatory proteins that bind to cyclin-dependent kinases (CDKs) to control the progression and timing of various stages in the cell cycle.

Apoptosis

A controlled and organized process of programmed cell death where cells shrink and condense, protecting organisms from damaged or cancerous cells.

Stem Cells

Undifferentiated biological cells that can divide and develop into specialized cell types to repair or build specific tissues.

Meiosis

Reduction cell division occurring in reproductive cells that involves two successive divisions to produce four haploid ($1n$) gametes.

Homologous Chromosomes

Pairs of chromosomes having the same length, centromere location, and gene positions, with one member inherited from each parent.

Hinge Joint

A type of joint that opens and closes in a single direction, such as the elbow or knee joints.

Ball and Socket Joint

A joint in which the rounded end of one bone fits into an indentation of another, allowing rotation in almost any direction, such as shoulder and hip joints.

Threshold Stimulus

The minimum stimulus required for a nerve cell to generate a nerve impulse.

Nonspecific Immunity

Innate general defenses present at birth that protect the body against a wide range of pathogens without targeting a specific organism.

Specific Immunity

Adaptive defense mechanisms developed by the lymphatic system that target and eliminate specific foreign pathogens using lymphocytes and antibodies.

Biosphere

The global ecological portion of Earth that supports life, encompassing all ecosystems and interactions between biotic and abiotic factors.

Biotic Factors

The living components within an organism's environment, such as plants, animals, and bacteria.

Abiotic Factors

The non-living physical and chemical components in an organism's environment, such as water, air, and temperature.

Niche

The functional role or position that an organism fulfills within its environment.

Mutualism

A symbiotic relationship between two or more living organisms in which both benefit from each other.

Commensalism

A symbiotic relationship between two organisms in which one benefits while the other is neither helped nor harmed.

Parasitism

A symbiotic relationship in which one organism benefits at the direct expense of harming another organism (the host).

Primary Succession

Ecological succession occurring on newly exposed surfaces devoid of topsoil, such as bare rock or cooled volcanic lava.

Secondary Succession

Ecological succession occurring in an area where an existing biological community was destroyed or removed, but topsoil remains intact.

Climax Community

A stable, mature biological community that undergoes minimal change in species composition over time.

Bioremediation

The environmental restoration technique using living organisms (such as prokaryotes, fungi, or plants) to remove toxic substances from a polluted area.

Biological Augmentation

The ecological practice of introducing natural predatory organisms into a disturbed ecosystem to help restore its balance.

Innate Behavior

Genetically programmed or instinctive behavior that depends solely on inheritance without prior learning or experience.

Learned Behavior

Behavioral responses acquired, modified, or refined through individual life experience and interaction with the environment.