IB Biology Topic B3.2: Transport Key Definitions

The attraction between water molecules and other surfaces, enabling water to cling to them and move against gravity.

Valves located between the atria and ventricles that prevent the backflow of blood.

The attraction between water molecules due to hydrogen bonding.

Specialized cells in phloem that assist sieve tube elements by providing metabolic support, including energy production.

The difference in concentration of a substance (e.g., oxygen or carbon dioxide) between two regions.

Definition:

Coronary arteries are specialized vessels branching from the aorta.

A statistical measure that quantifies the strength and direction of the relationship between two variables.

The diastolic pressure is the pressure exerted on the walls of the arteries when the heart is in the relaxation phase (diastole), and the ventricles are filling with blood.

A circulatory system in which blood passes through the heart twice in one complete cycle. There are two distinct circuits: the pulmonary circuit (lungs) and the systemic circuit (body tissues).

Capillaries with small pores (fenestrations) in their walls.

A soluble plasma protein that is converted into fibrin during clotting.

Horizontal gene transfer involves the direct exchange of genetic material between unrelated organisms, bypassing traditional parent-offspring inheritance. It is especially common in prokaryotes (bacteria and archaea).

The pressure exerted by a fluid on the walls of its container, in this case, the pressure exerted by blood against the walls of the capillaries.

Lignin is a complex, strong polymer deposited in the walls of xylem vessels.

Lymph is a clear, watery fluid that moves through the lymphatic system and carries nutrients, white blood cells, and other substances throughout the body.

A network of vessels, tissues, and organs that work together to drain excess tissue fluid and return it to the blood, while also aiding immune function.

Osmosis is the net movement of water molecules across a semi-permeable membrane from a region of lower solute concentration to a region of higher solute concentration.

The pressure that draws water into the capillaries due to the presence of solutes (especially proteins like albumin) in the blood.

A group of cells in the right atrium that regulates the heartbeat by initiating electrical impulses.

The liquid component of blood, consisting mostly of water, proteins, and other substances.

Plasmodesmata are microscopic channels that connect plant cells, allowing substances to move between them

A pulse is the pressure wave created by each heartbeat as blood travels through arteries near the skin’s surface.

A positive hydrostatic pressure in the roots that helps push water up the xylem when transpiration is low.

Valves located between the ventricles and the arteries that prevent blood from flowing back into the heart.