Lecture 8- The plant body Flashcards
97% of angiosperms belong to which two clades?
Monocots and eudicots
What features distinguish monocots?
Narrow leaves Veins in leaves- parallel One cotyledon Flower parts in multiples of three Primary vascualr bundle scattered
What features distinguish eudicots?
Broad leaves Veins in leaves are net like Two cotyledons Flower parts in multiples of 4 or 5 Primary vascular bundle in a ring
The remaining species of angiosperms resemble which of the two major clades more closely?
Eudicots
Give examples of monocot plants
Grasses, lilies, palms, orchids
Give examples of eudicot plants.
Soy beans, roses, sunflowers, maples
What are angiosperms?
Vascular plants characterized by double fertilization, a triploid endosperm, seeds enclosed in modified leaves called carpels
Flowering plants possess what three types of vegetative (non-reproductive) organs?
Roots, stems, leaves
What two basic systems are all organs organised into?
Shoot system and root system
What does the shoot system consist of?
Stems, leaves and flowers
What are nodes and internodes?
Nodes are points of attachment of stem to leaf, and the stem regions between successive nodes are internodes
What is the function of the stem?
To hold and display the leaves to the sun and provide connections for transport of materials between roots and leaves
What is the function of the leaves?
Photosynthesis
What is the function of the root system?
To anchor the plant in place and provide nutrition
What does the structure of vegetative organs include?
The overall shape, morphology
and the anatomy- the arrangement of component cells and tissues
What are the two principle types of root systems?
Taproot system- single, large, deep growing primary root accompanied by less prominent lateral roots- common in most eudicots
Monocots- fibrous root system- numerous thin roots, roughly equal in diameter
What are adventitious roots?
Roots that arise above ground from points along the stem- these can form when a piece of shoot is cut or broken from the plant and placed in water or soil. This enables the cutting to establish its self as a new plant- vegetative reproduction
What is a bud?
An embryonic shoot
What is the difference between an axillary bud and an apical bud?
Axillary buds are where each leaf meets a stem and can develop into a new branch. Apical buds are at the tip of stems or branches and produces upwards and outwards growth or develop into flowers
Some stems are highly modified. Explain how this is demonstrated by a potato, desert plants and runners.
The tuber of a potato is an underground stem.
Desert plants have large, water-retaining stems.
Runners in strawberry plants and Bermuda grass are horizontal stems from which roots grow at intervals. If links are broken, individual plants can grow on either side.
What is a blade and how is it attached to the plant?
A blade of a leaf is a thin, flat structure, attached to the stem by a stalk called a petiole.
How do leaves maximize the amount of sunlight that they receive during the day?
Some leaves track the sun over the course of the day- moving to constantly face it
Why may some leaves on the same plant have different shapes?
Genetic, developmental and environmental factors
What are the two types of leaf structure?
Compound leaves- consist of multiple leaflets arranged along an axis or central point. Simple leaves consist of a single blade. Doubly compound leaves is the result of further division of the axis.
What determines the shape of a leaf?
Differential growth of the leaf veins and the tissue between the veins determines overall shape of blade or leaflet
What types of modifications can occur to leaves during development in order to become specialised?
- Modified to become storage depots for energy rich functions (onion bulb)
- Water storage- such as in succulents
- Tendrils- support the plant by wrapping around other structures or plants (peas)