GCSE BIOLOGY PAPER 1

Light Microscope

A type of microscope developed in the mid-17th century that uses light to form an image, can view live specimens, and has a maximum magnification of up to $\times 2000$.

Electron Microscope

A type of microscope developed in the 1930s that uses electrons to form an image, requires dead specimens, has a maximum magnification of up to $\times 2000000$, and provides high resolution of approximately $0.2 \text{ nm}$.

Magnification

The factor by which an image is enlarged compared to the size of the actual object.

Resolution

The ability to distinguish between two separate points; higher resolution provides clearer details.

Eukaryotic Cells

Cells that contain a cell membrane, cytoplasm, and genetic material enclosed within a nucleus; examples include animal, plant, fungi, and protist cells.

Prokaryotic Cells

Smaller cells that contain a cell membrane, cytoplasm, ribosomes, and a cell wall, with genetic material present as a single loop of $DNA$ in the cytoplasm.

Cell Differentiation

The process by which an undifferentiated cell develops specific structures to perform a particular function.

Diffusion

The net movement of particles from an area of higher concentration to an area of lower concentration, a passive process that does not require energy.

Osmosis

The diffusion of water from a dilute solution to a concentrated solution across a partially permeable membrane.

Active Transport

The movement of substances from a dilute solution to a concentrated solution against a concentration gradient, requiring energy.

Chromosomes

Structures made of $DNA$ molecules that carry genes, located inside the nucleus, with body cells containing $23$ pairs (total of $46$).

Interphase

The longest stage of the Cell Cycle where the cell grows in size, increases the number of organelles, and replicates its $DNA$.

Mitosis

The stage of the cell cycle where one set of chromosomes is pulled to each end of the cell and the nucleus divides.

Stem Cell

An undifferentiated cell capable of dividing and differentiating into specialized cell types.

Binary Fission

A simple form of cell division in bacteria where one cell divides to form two identical cells.

Xylem

Plant tissue that transports water and mineral ions from roots upwards; consists of non-living hollow tubes reinforced with lignin.

Phloem

Plant tissue that transports dissolved sugars up and down the plant; consists of living tissue with sieve plates and companion cells.

Pathogen

Microorganisms, such as bacteria, viruses, protists, and fungi, that cause infectious diseases.

Phagocytosis

The process by which certain white blood cells engulf and digest pathogens.

Vaccination

The process of injecting small quantities of dead or inactive pathogens to stimulate immunity by producing antibodies.

Monoclonal Antibodies

Antibodies produced from a single cloned lymphocyte, used for various purposes including pregnancy tests and targeted cancer therapies.

Photosynthesis

The endothermic chemical process that converts carbon dioxide and water into glucose and oxygen, occurring in chloroplasts.

Aerobic Respiration

An exothermic reaction involving the conversion of glucose and oxygen into carbon dioxide and water, occurring in mitochondria.

Anaerobic Respiration

The process of respiration that occurs without oxygen, resulting in lactic acid in animals or ethanol and carbon dioxide in yeast and plants.