VCE Biology Unit 1 AoS2

How do plant and animal systems function?

Organelle

A structure within a cell which performs a specific function.

Cell

The basic structural and functional unit of living things.

Tissue

A collection of similar cells which work together to perform a particular function.

Organ

A collection of different tissues that work together to carry out a particular function within a system.

System

A collection of organs working together to achieve a major task in an organisim.

Root

The plant organ responsible for the absorption and storage of soil water and minerals. It acts as an anchor and structural support for the plant.

Stem

A plant organ which provides structural support, and allows the transport of water and nutrients.

Leaf

A plant organ which is the site of photosynthesis and the gas exchange.

Flower

A plant organ for sexual reproduction

Fruit

What a flower becomes post-fertilisation. Organ which protects and enables the dispersion of seeds.

Xylem

the vascular tissue in plants which conducts water and minerals upwards from the root

Phloem

the vascular tissue in plants which conducts sugars and other metabolic products downwards from the leaves.

Vascular bundle

a strand of conducting vessels in the stem or leaves of a plant, typically with phloem on the outside and xylem on the inside.

Stomata

Pores (largely) on the under-side of the leaf enable gas exchange and regulate water loss.

Guard cells

Two cells positioned around a stoma. Contain chloroplasts for photosynthesis. Swell with turgor pressure, controlling if the stomata are open or closed.

Waxy cuticle

A waxy layer secreted by the epidermis. (not cells)

Epidermis

Singer layer of cells below the cuticle. Transparent, allowing light to penetrate to the mesophyll cells below.

Palisade mesophyll

Primary photosynthetic cells of the leaf, containing many chloroplasts. Located beneath the upper epidermis.

Spongy mesophyll

Found beneath palisade mesophyll. Loosely packed, creating air spaces. Most gas exchange (O₂, CO₂) occurs here.

Glucose

C₆H₁₂O₆. Sugar produced during photosynthesis. Used by mitochondria to synthesis ATP.

Photosynthesis

Chemical process where sunlight energy is used to convert CO₂ and O₂ into glucose.

Homeostasis

Maintenance of a condition of the internal environment within narrow limits.

Stimulus

A detectable change in the (internal or external) environment that triggers a response in an organism.