UNIT 3: Kingdom Plantae Flashcards
Plants are
All multicellular
All photosynthetic
Cotyledon
Embryonic seed leaf
In early stage of plant development, cotyledons are used as a food source / photosynthesis
Monocotyledons
Have one embryonic seed leaf
Dicotyledons
Two embryonic seed leafs
Dermal tissue
Outer covering.
Functions in protection , gas exchange or absorption of water and minerals (depending on location)
Ground tissue
Makes up the bulk of the plant .
Functions in photosynthesis, storage or support (depending on its location)
Vascular tissues
Composed of xylem and phloem tissue
Functions in water and mineral transport (xylem) and food transport (phloem)
Meristematic tissue
Develops into each of the three types of tissue
Meristem
Composed of unspecialised cells that are continuously dividing by mitosis
Shoot system
Consists of stem, branches, petioles, buds, leaves, flowers, seeds and fruits. Functions: - photosynthesis - support - transport - sexual reproduction - food storage - gas exchange
Stem
Functions mainly in support and transport - but can function in photosynthesis ( if it is herbaceous). Also functions in growth. Divided into nodes and internodes. Nodes - regions where branching occurs Internodes - where no branching occurs Have lenticels
Lenticels
Small pores on the stem that function in gas exchange
Leaf
- thin organ with a large surface area.
- organ that makes food.
- contains the green pigment, chlorophyll
- the outer dermal layer secretes a waxy cuticle to prevent excess water loss.
- organ that also functions in transpiration
Parallel leaf veins
Veins run parallel, the entire length of the leaf e.g. grass, tulip, daffodil.
Most monocot plants have parallel Venetian
Net/ reticulate leaf vein
Veins spread out from a central vein called the midrib
Most dicot plants have net or reticulate venation
Internal leaf structure
- the leaf contains many internal air spaces that gives greater surface area for gas exchange.
- the cells that make up the internal area contain many chloroplasts that carry out photosynthesis
- the lower dermal layer has many pores, called stomata
- stomata openings and closing is controlled by guard cells
Flower arrangement between monocots and dicots
- monocots have flower parts arranged in multiples of three.
- dicots have flower parts arranged into multiples of four / five
Bud
Undeveloped shoot
Axillary bud
Present at the axil of leaf (between stem and petiole)
Apical bud
Present at the tip of the plant or the tip of a branch
Adventitious bud
Present in an unusual area of the plant - such as the stem, branch, root or even leaf
Root system
A network of underground branches that have various functions.
- anchorage
- absorbing water and minerals
- transport of absorbed water and minerals to the shoot system
- storage of food
- support
Tap root system
One main root growing downwards with small secondary roots e.g. carrot, dandelion
Fibrous root system
Main roots of equal size e.g. grass
Adventitious root system
Roots that grow in usual places such as the stem or branches e.g. ivy
Zone of protection
Consists of a root cap, enabling the root to push its way through the ground
Meristematic zone
Consists of meristematic tissue that divides rapidly by mitosis, creating new root tissue
Zone of elongation
Area of the root affected by growth regulators, where the cells increase in size
Zone of differentiation
Area of the root where unspecialised cells start to become specialised, becoming ground, dermal and vascular tissues.
Vascular system
Composed of xylem and phloem.
Xylem
- A dead tissue - there is no cytoplasm and no nuclei in xylem tissue.
- contains lignin that gives the tissue high strength.
- transports water and dissolved minerals upwards.
- composed of two types of cell: tracheids and vessels
Phloem
- A living tissue
- transports foods upwards and downwards, depending on where the food is needed.
- composed of companion cells and phloem sieve tubes
