OCR (A) Biology GCSE Topic 2: Scaling up

This set of flashcards covers key vocabulary and definitions related to cell transport mechanisms, cell division, and plant and animal biology as discussed in the OCR (A) Biology GCSE curriculum.

Diffusion

The spreading out of particles resulting in a net movement from an area of higher concentration to an area of lower concentration.

Passive process

A process that does not require energy.

Osmosis

The movement of water from a less concentrated solution to a more concentrated one through a partially permeable membrane.

Isotonic solution

A solution with the same concentration of solutes as the cell, resulting in no net movement of water.

Hypertonic solution

A solution with a higher concentration of solutes than the cell, causing water to move out of the cell.

Hypotonic solution

A solution with a lower concentration of solutes than the cell, causing water to move into the cell.

Active transport

The movement of particles from an area of lower concentration to an area of higher concentration, requiring energy.

Interphase

The stage in the cell cycle where the cell grows, organelles increase in number, proteins are synthesized, and chromosomes are replicated.

Mitosis

A type of cell division where one cell divides to form two identical daughter cells.

Cytokinesis

The division of the cytoplasm and cell membranes to form two identical daughter cells.

Differentiation

The process by which a cell gains new sub-cellular structures to suit its role.

Stem cells

Undifferentiated cells that can divide to produce various specialized cells.

Xylem

Vascular tissue in plants that transports water and minerals from roots to shoots.

Phloem

Vascular tissue in plants responsible for transporting food substances made in the leaves.

Transpiration

The loss of water vapor from the leaves and stems of a plant.

Guard cells

Cells that open and close the stomata to regulate gas exchange and water loss.

Surface area to volume ratio

A measure of the amount of surface area per unit volume, affecting exchange rates in organisms.

Alveoli

Tiny air sacs in the lungs that provide a large surface area for gas exchange.

Concentration gradient

The difference in concentration of substances between two areas.

Turgor pressure

The pressure exerted by the fluid in the vacuole against the cell wall, helping to keep the plant upright.

Plasmolysis

The process in which plant cells lose water and the cell membrane detaches from the cell wall.

Lignin

A chemical deposited in xylem that strengthens the plant and helps withstand water pressure.

Sieve plates

Structures in phloem cells that facilitate the transportation of nutrients through the plant.

Osmotic pressure

The pressure required to prevent water movement across a selectively permeable membrane.

Heart structure

The heart has muscular walls, four chambers, and valves to ensure unidirectional blood flow.

Red blood cells

Cells that contain hemoglobin for transporting oxygen throughout the body.

Plasma

The liquid component of blood that carries blood cells and nutrients.

Veins

Blood vessels that carry blood towards the heart.

Arteries

Blood vessels that carry blood away from the heart.

Capillaries

Small blood vessels that allow for the exchange of substances between blood and tissues.

Mitochondria

Organelles that produce energy through respiration, present in cells for energy supply.

Amino acids

The building blocks of proteins, essential for cell function and repair.