VCE Biology 2025: Functioning Systems

aorta

The large artery that carries blood from the left ventricle of the heart to the body.

arteriole

A small blood vessel that stems from an artery and leads to capillaries.

artery

A blood vessel with thick, elastic walls, through which blood flows from the heart to the rest of the body.

atrium (pl. atria)

A chamber of the heart that receives blood returning from the body or the lungs, before passing the blood into a ventricle.

capillary

A tiny blood vessel with a wall only one cell thick, across which exchange occurs between blood and tissues.

cell differentiation

The process by which a cell becomes specialized in order to perform a specific function.

cell replication

A process by which cells duplicate their genetic material and then divide to yield two daughter cells.

connective tissue

Tissue that connects, separates or supports tissues or organs in the body.

haemoglobin

A protein molecule in red blood cells that carries oxygen from the lungs, and returns carbon dioxide from the tissues to the lungs.

left atrium

Receives oxygenated blood from the lungs.

left ventricle

Pumps oxygenated blood out to the body via the aorta.

multicellular

Consisting of two or more specialised cells that have identical DNA, are responsible for specific functions, and depend on each other for survival.

organ

A structure, consisting of different tissues, that carries out one or more specific functions.

phloem

Plant tissue through which sugars and other organic compounds are distributed to different parts of a plant. Composed of living cells.

pulmonary vein

In humans, a blood vessel that carries oxygen-rich blood from the lungs to the left atrium of the heart.

right atrium

Receives deoxygenated blood from the body.

right ventricle

Pumps deoxygenated blood to the lungs.

root hair

A very thin extension of an epidermal cell of a root that work to increase the root's surface area, making the absorption of water and minerals from soil more efficient.

semilunar valves

Pocket like structures attached at the point at which the pulmonary artery and the aorta leave the ventricles.

stoma (pl. stomata)

Pores in the leaf epidermis, bounded by specialised guard cells that open and close the pore. The main routes through which gas exchange occurs in plants, and through which water loss is regulated.

system

A group of organs in animals that work together for a particular purpose. The major systems in humans are the integumentary system, skeletal system, circulatory system, muscular system, digestive system, nervous system, endocrine system, respiratory system and excretory system.

tissues

Groups of specialised cells working together to carry out a particular function.

translocation

The transport of organic substances in the phloem of a vascular plant. It is an active process and requires an expenditure of energy by the plant.

transpiration

The evaporation of water, mainly, through stomata. A passive process largely controlled by the humidity of the atmospheric and the moisture content of the soil.

transpiration stream

The flow of water within a plant, from the uptake by the roots to the loss of water as water vapour to the environment via the leaves.

tricuspid valve (also called the right atrio-ventricular valve)

One of four valves found in the heart that lie between the right atrium and the right ventricle. The function of the valve is to prevent back flow of blood into the right atrium.

valve

A specialised structure in circulatory systems that allows movement in one direction only. In humans, valves occur in the heart, veins and lymph vessels.

vascular (adj. vascularised)

Having vessels that transport fluids.

vascular bundle

A grouping of vascular tissues in vascular plants, containing both xylem and phloem. Vascular bundles are continuous, from the roots into the stem, branches and leaves.

vascular tissue

The tissue that conducts water and nutrients from the roots to the leaves in vascular plants. It consists of two types of tissue: xylem and phloem.

vein

A blood vessel that carries blood towards the heart. All veins except the pulmonary veins carry deoxygenated blood.

vena cavae

Large veins that return deoxygenated blood from the body into the heart.

ventricle

A muscular chamber of the heart that pumps blood from the heart to the rest of the body.

venule

A small vessel that connects capillaries to a vein.

xylem

The tissue in vascular plants that transports water and mineral ions upwards from the roots. It consists of hollow chains of dead cells.

xylem vessel

A long tube consisting of cells joined end to end, through which water and mineral ions are transported from the roots to the leaves in a vascular plant.