Biology AS Level Vocab- OCR- Chapters 1 and 2


A Levels Biology (AS Biology) Flashcards on Biology AS Level Vocab- OCR- Chapters 1 and 2, created by Laura Perry on 04/08/2014.
Laura Perry
Flashcards by Laura Perry, updated more than 1 year ago
Laura Perry
Created by Laura Perry over 9 years ago

Resource summary

Question Answer
Magnification The number of times greater an image is than the object.
Resolution The ability to distinguish two separate points that are distinct from each other.
Ultra-structure (or Fine Structure) Detailed structure of the internal components of cells as revealed by the electron microscope, rather than the light microscope.
Mitosis Nuclear division that results in the formation of two cells that are genetically identical to the parent cell.
Meiosis Nuclear division that results in the formation of four cells that each contain half the number of chromosomes as the parent cell (haploid).
Chromosome A linear DNA molecule wrapped around histone proteins, found in the nucleus.
Gene A short sequence of DNA that carries the code for the synthesis of one specific polypeptide (protein).
DNA Deoxyribonucleic Acid- a polymer of nucleotide molecules that form the instructions for the synthesis of proteins found within organisms.
Mitochondria A membrane bound organelle responsible for the generation of ATP molecules by aerobic respiration.
Rough Endoplasmic Reticulum A membrane bound organelle covered with ribosomes- the site of protein synthesis.
Flagella Protein based structure that extends from the membrane and is involved in moving the cell itself through a medium.
Prokaryotic Organism A single celled organism that does not contain a true nucleus.
Eukaryotic Organism An organism consisting of cells that contain a true nucleus and membrane bound organelles.
Hydrophilic Associates with water molecules easily.
Hydrophobic Water repelling molecule.
Channel Protein A protein pore that spans the membrane, through which very small ions and water soluble molecules may pass.
Diffusion The net movement of molecules or ions in a gas or liquid from an area of high concentration to an area of lower concentration.
Osmosis The movement of water molecules from a region of high water potential to a region of lower water potential across a partially permeable membrane.
Active Transport The movement of substances across membranes against a concentration gradient that requires the use of energy in the form of ATP via transport proteins.
Facilitated Diffusion The passive movement of molecules down a concentration gradient, aided by transport proteins.
Enzymes A globular protein molecule with 3D structure that acts as a biological catalyst.
Molecular Shape The particular shape of a molecule.
Complementary Shape When two molecules have (matching) shapes which allow them to bind together (Lock and Key).
Target Cell A cell with specific receptors on the cell surface membrane which can receive a signal molecule (like a hormone).
Endocytosis The process of taking materials into the cell by surrounding them with part of the plasma membrane, which then pinches off to form a vesicle inside the cell. This is an active process requiring ATP.
Exocytosis The process of removing materials from a cell by fusing vesicles with the plasma membrane. This is an active process requiring ATP.
Phagocytosis Endocytosis of large solid materials such as microorganisms or cell fragments.
Zygote Diploid cell made from the fusion of male and female gametes.
Differentiation The development and changes seen in cells as they mature to form a specialised cells.
A tissue A similar group of cells that perform a particular function.
Organ A collection of tissues that work together to perform a specific function or a set of functions.
Metabolism All the chemical reactions that take place in the cells of an organism.
Plasma/Cell Surface Membrane The outside surface of a organism or cell.
Surfactant A chemical that can reduce the surface tension of a film of water.
Smooth Muscle A type of muscle (involuntary muscle) found mostly in certain internal organs and involved in involuntary movements such as peristalsis.
Elastic Ability to stretch and recoil.
Intercostal Muscle Muscles between the ribs responsible for moving the ribcage during breathing.
Double Circulatory System Transport system in which blood travels twice through the heart for each complete circulation of the body.
Respiration The process in which energy is released from complex molecules (such as glucose) within a cell and transferred to molecules of ATP.
Atrium One of the upper chambers of the heart.
Ventricle The lower chambers in the heart.
Coronary Arteries Arteries that carry blood to the heart muscle.
Hydrostatic Pressure The pressure created by a fluid pushing against the sides of a container.
Diastole The period when the heart muscles in the ventricles are relaxing and blood pressure is at its lowest.
Systole The stage in the heart cycle when heart muscles contract to pump blood.
Sinoatrial Node (SAN) A region in the right atrium from which the wave of excitation is initiated.
Staining The use of chemical or computer imaging to provide contrast between different parts of a cell for identification.
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