VCE Biology Units 1 and 2: Functioning Systems and Homeostasis

Comprehensive vocabulary flashcards covering plant and animal functioning systems, homeostasis, thermoregulation, blood glucose control, and osmoregulation based on VCAA VCE Biology Unit 1.

Vascular plants

Multicellular land plants whose cells are organised at the system, organ, and tissue levels, featuring a shoot system and a root system.

Meristematic tissues

Plant tissues composed of cells that can undergo cell division and continue to divide for the life of the plant, typically found in root and shoot tips.

Parenchyma tissue

The most common plant ground tissue, composed of living thin-walled cells that serve as sites of photosynthesis in leaves and starch storage in roots.

Xylem tissue

A complex vascular tissue consisting of hollow dead cells (tracheids and vessels) with walls hardened by lignin, responsible for transporting water and minerals.

Phloem tissue

A complex vascular tissue consisting of living cells that transport sugars, such as dissolved sucrose, and other organic compounds throughout the plant.

Root hairs

Extensions of epidermal cells in the root that increase surface area to facilitate the uptake of water from the soil by osmosis.

Transpiration

The loss of water vapour from plant leaves, primarily through the stomata, which pulls water through the xylem from the roots.

Stomata

Pores located mainly in the lower epidermis of leaves that serve as exit points for water vapour and entry points for carbon dioxide.

Guard cells

Pairs of specialized epidermal cells that surround each stoma and regulate its opening and closing based on their turgor pressure.

Cohesion

The property of water molecules tending to stick together, which helps maintain an unbroken column of water in the xylem.

Adhesion

The property of water molecules tending to stick to the walls of a container, such as xylem vessels, preventing the water column from pulling away.

Epithelial tissues

Sheets of cells that cover internal and external surfaces of the body, functioning in protection, absorption, and secretion.

Muscle tissues

Tissues that contract to enable movement, categorized into skeletal (striated), cardiac, and smooth muscle.

Connective tissues

The most abundant tissue type that provides structural support, energy storage, and transport, including bone, cartilage, fat, and blood.

Nervous tissues

Tissues made of different kinds of nerve cells (neurons) that are found in the brain, spinal cord, and peripheral structures.

Alimentary canal

Also known as the gastrointestinal tract, it is an open tube extending from the mouth to the anus consisting of hollow organs like the stomach and intestines.

Mechanical digestion

The physical breakdown of food into smaller pieces, such as through chewing or the churning action of the stomach, to increase surface area for enzymes.

Chemical digestion

The process of using enzymes to break down macromolecules like proteins, carbohydrates, and lipids into smaller sub-units or monomers.

Villi

Finger-like projections on the surface of the small intestine mucosa that greatly increase the surface area for the absorption of nutrients.

Homeostasis

The outcome of processes that maintain a relatively stable internal environment for physiological variables and the chemical composition of body fluids.

Negative feedback

A homeostatic mechanism where the response counteracts or negates the original stimulus to move a variable back toward its set point.

Positive feedback

A cycle of continuing change in which an original change is increasingly amplified, moving a system further from its set point.

Hypothalamus

A region of the brain that acts as a control centre for many homeostatic variables, including body temperature, blood glucose, and water balance.

Endotherms

Animals that maintain a relatively steady internal core body temperature regardless of variation in the external environmental temperature.

Islets of Langerhans

Specialized clusters of endocrine cells in the pancreas containing alpha cells and beta cells that regulate blood glucose levels.

Insulin

A peptide hormone produced by pancreatic beta cells that lowers blood glucose levels by stimulating glucose uptake into cells and conversion to glycogen.

Glucagon

A peptide hormone produced by pancreatic alpha cells that raises blood glucose levels by stimulating the liver to break down glycogen into glucose.

Glycogen

A polymer built of glucose sub-units stored in the liver and skeletal muscle as a short-term energy reserve.

Nephron

The functional unit of the kidney, which consists of the Bowman’s capsule, proximal tubule, loop of Henle, distal tubule, and collecting duct.

Antidiuretic hormone (ADH)

A hormone released by the posterior pituitary that increases water reabsorption in the kidney's collecting ducts by inserting aquaporins into plasma membranes.

Type 1 diabetes

A chronic autoimmune disease where the immune system destroys the beta cells of the pancreas, leading to little or no insulin production.

Hyperthyroidism

A condition resulting from an overactive thyroid gland that produces excessive thyroxine, leading to an increased basal metabolic rate.

T3 and T4

Thyroid hormones (triiodothyronine and thyroxine) that require iodine for production and regulate metabolism, growth, and development.

Piloerection

An involuntary response where tiny muscles at the base of hair follicles contract to raise hair or fur, creating an insulating layer of air.

Brown adipose tissue (BAT)

A type of fat tissue specifically used for heat-producing metabolism, releasing energy from fatty acids as heat rather than ATP.

Osmoregulation

The homeostatic process of controlling the water content and solute concentration (osmolality) of body fluids.