AS Level Biology Vocabulary Review

These flashcards cover key vocabulary terms and definitions from the AS Level Biology lecture notes.

Microscopy

The use of microscopes to observe structures that are too small to be seen by the naked eye.

Resolution

The ability of a microscope to distinguish two objects as separate.

Magnification

The process of enlarging the apparent size of an object.

Eukaryotic cells

Complex cells that contain a nucleus and membrane-bound organelles.

Prokaryotic cells

Simpler cells without a membrane-bound nucleus or organelles.

Cytoplasm

The fluid inside a cell that contains organelles and is the site of metabolic processes.

Ribosomes

Cellular structures that synthesize proteins by linking amino acids.

Mitochondria

Organelles that generate ATP through aerobic respiration.

Chloroplasts

Organelles found in plant cells that conduct photosynthesis.

Homeostasis

The process by which organisms maintain a stable internal environment.

Diffusion

The passive movement of molecules from an area of higher concentration to an area of lower concentration.

Osmosis

The diffusion of water molecules across a selectively permeable membrane.

Cell membrane

A biological membrane that separates and protects the interior of a cell from the outside environment.

Active transport

The process of moving molecules across a cell membrane against their concentration gradient, requiring energy.

Cohesion

The attraction between molecules of the same substance, important for water movement in plants.

Transpiration

The process through which water evaporates from the aerial parts of plants.

Antigen

A substance that induces an immune response, especially the production of antibodies.

Antibody

A protein produced by plasma cells that specifically binds to antigens to neutralize them.

Pathogen

An organism that causes disease, such as bacteria, viruses, or fungi.

Phagocytosis

The process by which a cell engulfs large particles or other cells.

Vaccination

A method of inducing immunity by exposing the body to an antigen.

Gene mutation

A change in the nucleotide sequence of a gene, which can lead to changes in the protein it encodes.

Ecosystem

A community of living organisms and their physical environment interacting as a system.

Producers

Organisms that produce their own food, typically through photosynthesis.

Consumers

Organisms that obtain energy by feeding on other organisms.

Decomposers

Organisms that break down dead organic material, returning nutrients to the ecosystem.

Nitrogen fixation

The process of converting nitrogen gas from the atmosphere into a form that plants can use.

Photosynthesis

The process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll.

Chlorophyll

The green pigment found in plants that absorbs light energy for photosynthesis.

Bioaccumulation

The accumulation of substances, such as pesticides or other chemicals, in an organism.

Epidemiology

The study of how diseases affect the health and illness of populations.

Hemoglobin

The protein in red blood cells that carries oxygen.

Enzyme

A protein that acts as a catalyst to speed up chemical reactions in biological processes.